[{"content":"","permalink":"https://murli-shenoy.com/pages/blog/","summary":"","title":"Blog"},{"content":" Digital Minimalism: Choosing a Focused Life in a Noisy World ","permalink":"https://murli-shenoy.com/pages/intersting-books/","summary":"\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https://www.goodreads.com/book/show/40672036-digital-minimalism\"\u003eDigital Minimalism: Choosing a Focused Life in a Noisy World\u003c/a\u003e\u003c/li\u003e\n\u003c/ul\u003e","title":"Interesting Books list"},{"content":"I’ve had this idea in mind for a while, an E-paper display that is connected to the internet.\nIn this blog post, I want to freeze the high-level idea and the project execution plan. Hacker/maker Extraordinaire Sprite_TM has done something before on similar lines. I’m planning to build my own version from scratch while adding some new features\nI use a combination of physical sticky notes, along with the reminders and notes app on my Apple devices for improving my productivity at work and at home. I feel that it would be a great idea if could somehow combine these three tools into one device, and this is the first step towards it. Here’s a block diagram of my Idea.\nHere are the major components of the project\nthe cloud app running on Digital Ocean VPS the Wifi to low power 2.4ghz radio bridge (Something like the Canny) The Epaper module(Hardware+Firmware) The cloud app should be able to authenticate me and be able to get data securely via the API, I’m thinking of starting with OneNote web API as it seems to be easier to get started with. The output of this app would be a text file with some additional info (like date and some unique id for the target E-Paper display)\nThe bridge should be able to query the server and be able to translate the query from the display to a cURL call or something.\nThe Epaper module should have some intelligence and have the ability to query the bridge and display the text (or images). Also, I would like this module to have like a Name tag mode, would make for a cool conversation starter at Events/Meetups.\nI’ll post detailed blog posts on each of the components as I finish them. This project has lots of components and involves putting together a lot of components. Also, secure communication between the three components would be an important part of the design.\n","permalink":"https://murli-shenoy.com/posts/project-idea-low-power-eink-display/","summary":"\u003cp\u003eI’ve had this idea in mind for a while, an E-paper display that is connected to the internet.\u003c/p\u003e\n\u003cp\u003eIn this blog post, I want to freeze the high-level idea and the project execution plan. Hacker/maker Extraordinaire Sprite_TM has done something before on \u003ca href=\"http://spritesmods.com/?art=einkdisplay\"\u003esimilar\u003c/a\u003e lines. I’m planning to build my own version from scratch while adding some new features\u003c/p\u003e\n\u003cp\u003eI use a combination of physical sticky notes, along with the reminders and notes app on my Apple devices for improving my productivity at work and at home. I feel that it would be a great idea if could somehow combine these three tools into one device, and this is the first step towards it. Here’s a block diagram of my Idea.\u003cimg alt=\"Block diagram\" loading=\"lazy\" src=\"/posts/project-idea-low-power-eink-display/images/block_diag.jpg\"\u003e\u003c/p\u003e","title":"Project Idea: Low power Eink display"},{"content":"The Idea for this post struck me on a hot summer day here in California, it was a 100F outside and my phone mounted on the car dashboard wouldn’t charge as fast(like 1% in like 30 minutes) although the phone indicated that it was in fast charge mode and I could not see any other issues with the charger or the charging cable, maybe the heat was affecting the charge rate?, I had to find out for myself.\nThere are two broad Fast charging technologies out there, Qualcomm’s QuickCharge and Oppo’s VOOC charging. Most mainstream smartphone brands use Quickcharge, while smartphone brands like Oppo and One plus use VOOC based charging technology. Both technologies are really interesting and solve the same problem using different approaches. This post is primarily about Qualcomm’s quick charge 2.0, which was implemented in the Galaxy Note 4(circa 2014) that I had on hand. Newer phones use QC 3.0 or more recently QC 4.0.\nInstrumentation: I came across this really neat little LTC2943 chip from Linear Tech (now part of Analog Devices). I think the target application for this chip is laptop Lithium Ion battery charge monitoring, but it should work well for this application.\nThe schematic is as shown below, basically, the Rsense is hooked in between the Charger Side Vbus and the Phone side Vbus\nI then needed a device that could talk to the LTC2943 and log the data to my computer over USB. Some Arduino code running on the Atmel Atmega328p Xplained Mini did the trick. The Xplained board also has debugging capabilities which made prototyping easier. the debugger onboard can also act as a USB to serial bridge so all I needed to do was ensure the output in proper format and I could copy the data from the serial terminal to a CSV for easier processing.\nThe actual breadboard setup(this is a quick and dirty setup that I came up with, worked well for this test)\nOnce the instrumentation was in place I basically ran the test twice once with quick charge enabled and once without.\nAnalysis:\nI wrote some quick python code to analyze the data from the two test runs. Check the screen capture below for the results\nA few quick observations from the data (tl;dr):\nQuick charge seems to violate the USB Vbus voltage spec Quick charge uses the D+ and D- for voltage negotiation, hence you wouldn’t risk damaging a non-QC device by plugging into a QC compatible charger Quick charge algorithm seems to back’s off on the current under the following conditions When the phone is being used or if the battery is being loaded above a certain threshold when the temperature crosses a certain threshold, this is to prevent battery over heating Quick charge is less efficient than regular USB charging, this is evident from the higher amount of heat being dissipated by the end device Additional references\nInteresting TI app note on implementing QC 2.0 Github link to the firmware/software/hardware used for this experiment: https://github.com/hmms/fast-charge-analysis ","permalink":"https://murli-shenoy.com/posts/the-magic-behind-fast-charging/","summary":"\u003cp\u003eThe Idea for this post struck me on a hot summer day here in California, it was a 100F outside and my phone mounted on the car dashboard wouldn’t charge as fast(like 1% in like 30 minutes) although the phone indicated that it was in fast charge mode and I could not see any other issues with the charger or the charging cable, maybe the heat was affecting the charge rate?, I had to find out for myself.\u003c/p\u003e","title":"The ‘Magic’ behind Fast Charging"},{"content":"Recently, I built a touch activated LED toy based on the Attiny85V from Microchip (née Atmel). The schematic is shown below\nI got the PCBs made from every hobbyist’s favorite PCB manufacturer OSHpark. On the surface, the project seemed pretty simple. It gave me an opportunity to work on touch sensors and learn their functioning and implementation. I decided to go with an external touch sense solution(MTCH102 from Microchip as well), as I had plenty of board space to spare and, the it wouldn’t add much cost to the BOM. Also it would save me a lot of development time as implementing a robust power efficient capacitive touch library could be an interesting project in itself!\nwhen starting with the project I set the following constraints:\nCost \u0026lt; $12 (for qty \u0026lt; 10) Power (powered from a CR2032, the battery should last at least a month) The cost target was an easy one, the most expensive component was the Attiny itself at around $2.25, other components were virtually “free” .\nMeeting the power target though was a bit challenging. This post is mostly about how I was able to reduce the power consumption, mostly through firmware modifications.\nUtilizing the sleep mode was an obvious choice since that could improve the standby time of the device literally by orders of magnitude. I used the following setup to measure sleep current. Vd was the vdrop across the rather large shunt. This rather large shunt worked for me since I was only concerned about the sleep/standby current and the voltage drop across the shunt would be pretty minuscule across the resistor at such low currents (\u0026lt;1 mA).I used a Vichy VC99 DMM and my Rigol Ds1054z (this scope is amazing value for the money!, mine doesn’t play well with USB thumb drives though 😦 ) to measure and analyse the current draw. 2. on initial measurement through the DMM the current draw seemed be varying quite a bit, this took me down another rabbit hole of how the touch sensor actually functioned. the MTCH102 has a pretty interesting power down mode, and the datasheet doesn’t do it enough justice. I was using the aptly named Low-power mode in my implementation. which basically involved tying down the MTPM, low-power mode selection pin to ground\n3. down the rabbit hole we go! It seems that the chip implements a pretty intersting psuedo-random algorithm to scan during the burst mode. the datasheet just calls it the burst scan. The chip sends out random length of pulses to the sense pad. The pulses are always in multiples of 16. And always between one and 10 sets of these 16 pulses are sent out.\none set of pulses\n4. This reflected on the current draw was as well, when the chip would be in burst scan mode the power consumption was up to 1.2mA. the scope capture below shows the Vd (across the 100Ohm shunt) when two sets of pulses were sent out through the sense pin.\n5. the only work around for this was to use the smart scheduling mode. This way I could control when the burst scan occurred, instead of every 256 ms i could set it occur say every second or so. I could go this route cut down the power consumption significantly! but then I would have to respin the board 😦\n6. but wait… the base line power consumption when the MTCH102 in sleep was still kinda high. about 300uA. a google search later, is stumbled upon this app note about reducing power consumption on the AVR. one of the first things that they had mentioned was to enable the internal pull ups on un used GPIOs to prevent power drain due to floating gates. I had three unused GPIOs that were essentially floating, made changes to the code and viola! I was able to shave off ~100uA\n7. with sleep mode and implementing the internal pull ups and disabling the unused modules I was able to get the average current consumption to under 200uA. a typical CR2032 cell is rated for 240mAh. this would give me an estimated standby time of about 1200 hours (or 50 days). Also the internal resistance of the cell increases as its charge depletes. Also considering the device consumes ~20mA when awake for about two seconds. Assuming the device wakes up once a day, we should theoretically still have enough charge for a run time of over 30 days(240mAh – 0.03mAh- 144mAh = 95.97mAh leftover).\nTo conclude I think this project was an overall success and met its primary goals. There is some room for optimization and I think the power consumption can still be reduced further, but for now I think I should move on to the next project!\n","permalink":"https://murli-shenoy.com/posts/fun-with-capacitive-touch-and-low-power-circuit-design/","summary":"\u003cp\u003eRecently, I built a touch activated LED toy based on the Attiny85V from Microchip (née Atmel). The schematic is shown below\u003c/p\u003e\n\u003cp\u003e\u003cimg alt=\"Capture2\" loading=\"lazy\" src=\"/posts/fun-with-capacitive-touch-and-low-power-circuit-design/images/capture2.png\"\u003e\u003c/p\u003e\n\u003cp\u003eI got the PCBs made from every hobbyist’s favorite PCB manufacturer \u003ca href=\"https://oshpark.com/\"\u003eOSHpark\u003c/a\u003e. On the surface, the project seemed pretty simple. It gave me an opportunity to work on touch sensors and learn their functioning and implementation. I decided to go with an external touch sense solution(\u003ca href=\"http://ww1.microchip.com/downloads/en/DeviceDoc/40001793A.pdf\"\u003eMTCH102\u003c/a\u003e from Microchip as well), as I had plenty of board space to spare and, the it wouldn’t add much cost to the BOM. Also it would save me a lot of development time as implementing a robust power efficient capacitive touch library could be an interesting project in itself!\u003c/p\u003e","title":"Fun with capacitive touch and low power circuit design"},{"content":"Yesterday I visited Alamere Falls, near Bolinas,CA.\nWe started at the Palomarin Trailhead (there’s plenty of parking there, it being peak season though we had a hard time finding parking)\nIt’s a rather long hike (8 mi+)but large sections of trail have good tree cover and it was very foggy when we visited. do remember to pack as much water as you can and some energy bars.Note that there’s no clear sign or marking indicating the trail that leads to the waterfall. I suspect that this might be due to the fact that trail is quite dangerous and steep, and the authorities don’t want people to go there. I used the offline maps feature in here maps to find my way.\nThe way to get there from the trail head is as follows, Follow along the signs for coast trail, then take the Alamere falls trail, the trail length is around ~4.4mi from the trail head to the waterfall.\nThere are a few lakes on the trail as well, so pack some gear along if you plan on taking a dip.\nLocation on google maps for Alamere Falls.\nAlso if you’re driving from the south (through Stinson Beach)there a few scenic spots along the Bolinas lagoon waterfront.\nHere are a few pictures from the trip.\nCoast trail\nPelican Lake\nCoast Trail\nAlamere Falls\nBolinas lagoon waterfront.\n","permalink":"https://murli-shenoy.com/posts/hiking-visit-to-alamere-falls/","summary":"\u003cp\u003eYesterday I visited Alamere Falls, near Bolinas,CA.\u003c/p\u003e\n\u003cp\u003eWe started at the Palomarin Trailhead (there’s plenty of parking there, it being peak season though we had a hard time finding parking)\u003c/p\u003e\n\u003cp\u003eIt’s a rather long hike (8 mi+)but large sections of trail have good tree cover and it was very foggy when we visited. do remember to pack as much water as you can and some energy bars.Note that there’s no clear sign or marking indicating the trail that leads to the waterfall. I suspect that this might be due to the fact that trail is quite dangerous and steep, and the authorities don’t want people to go there. I used the offline maps feature in \u003ca href=\"https://play.google.com/store/apps/details?id=com.here.app.maps\"\u003ehere maps\u003c/a\u003e to find my way.\u003c/p\u003e","title":"Hiking: Visit to Alamere Falls"},{"content":"It was a lazy Sunday afternoon, and I was craving something that’s tasty, but not too difficult to make and pasta sounded like a good idea. I really love creamy Alfredo sauce, but i had no parmesan cheese on hand. I also like tomato pasta sauce, but when made fresh. I really hate the taste of store bought pasta sauces, they are way too sour and leave a weird aftertaste. But these sauces are super convenient, so I always have them in stock.\nSo, the only stuff I had on hand was tomato (with garlic and basil) pasta sauce, heavy whipping cream and penne pasta. I cooked the pasta as per the instructions on the box, then drained the pasta. Heated some butter in the pan, added the tomato pasta sauce and while it was about to heat up added some of the heavy cream, garlic powder, dried basil leaves, and Voila!. the result was this awesome creamy, rich bright reddish orange pasta sauce, that was easy to make and tasted awesome(and looked beautiful too). I added some finely chopped cilantro to the sauce too, since I really love the taste of fresh cilantro.\n","permalink":"https://murli-shenoy.com/posts/pasta-sauce-hack-how-to-make-creamy-tomato-pasta-the-easy-way/","summary":"\u003cp\u003eIt was a lazy Sunday afternoon, and I was craving something that’s tasty, but not too difficult to make and pasta sounded like a good idea. I really love creamy Alfredo sauce, but i had no parmesan cheese on hand. I also like tomato pasta sauce, but when made fresh. I really hate the taste of store bought pasta sauces, they are way too sour and leave a weird aftertaste. But these sauces are super convenient, so I always have them in stock.\u003c/p\u003e","title":"Pasta sauce hack: How to make creamy tomato pasta the easy way."},{"content":"I started work on a new design, I have long had a desire to create a “product” from scratch using minimal off-the-shelf stuff. This design should help me achieve that goal, and help me learn project management(albeit on a micro scale! :P). Last year I spent some time on an esp8266 based design, new ideas got added to the design midway and a couple iterations later, i have OSHpark purple “art”. FEATURE CREEP, as it’s called, its very hard to fight off.\nThis time i decided to start simple. The design has tight constraints (ultra low power consumption, dimesions) but fewer variables that might get affected by feature creep. I feel, I have mostly been successful to fight it off this time. I wouldn’t tell what the project is just yet, and i haven’t committed it to a public git repo yet(of course, it’ll be OSH). I shall make it public soon 🙂 . I think it’ll be fun, and hopefully I teach myself a few lessons in project management, and how to be persistent and finish my hobby projects!\nIn the mean time here’s a sneak peek of the schematic! 😀\n","permalink":"https://murli-shenoy.com/posts/working-on-a-secret-project-and-fighting-feature-creep/","summary":"\u003cp\u003eI started work on a new design, I have long had a desire to create a “product” from scratch using minimal off-the-shelf stuff. This design should help me achieve that goal, and help me learn project management(albeit on a micro scale! :P). Last year I spent some time on an esp8266 based design, new ideas got added to the design midway and a couple iterations later, i have OSHpark purple “art”. FEATURE CREEP,  as it’s called, its very hard to fight off.\u003c/p\u003e","title":"Working on a “secret” project, and fighting feature creep!"},{"content":"Saw this post on hackaday and decided to work on fixing my own Mx Master which had the infamous scroll wheel issue. I could not toggle between the scroll modes of the mouse. The feature stopped working the very next day i started using the mouse. It seems to be a design issue on logitech’s part. But its a quick and simple fix, check the hackaday post above for more info.\n","permalink":"https://murli-shenoy.com/posts/quick-post-logitech-mx-master-fix/","summary":"\u003cp\u003eSaw \u003ca href=\"http://hackaday.com/2016/05/26/fixing-a-complicated-scrollwheel/\"\u003ethis\u003c/a\u003e post on hackaday and decided to work on fixing my own Mx Master which had the infamous scroll wheel issue. I could not toggle between the scroll modes of the mouse. The feature stopped working the very next day i started using the mouse. It seems to be a design issue on logitech’s part. But its a quick and simple fix, check the hackaday post above for more info.\u003c/p\u003e","title":"Quick post: Logitech Mx MASTER Fix"},{"content":"Today a coworker of mine gave me his old Philips Sonicare toothbrush. He said it had stopped charging and would no longer work. That was a good opportunity for a tear down 😉\nLets see what makes this baby chooch….(As the great man himself said https://www.youtube.com/watch?v=lA0kiYqyBmo)\nThere’s very little to this device. it seems like there’s just a micro controller running the show, like every other product. (there’s more horsepower in a toothbrush these days than an a 50 year old Supercomputer!) it probably does the following tasks( my guesstimate)\nRunning the motors Reading user input via the two push buttons (I accidentally De-soldered one Push button, while trying to De-solder the battery) Battery charging and discharging LEDs and Blinkenlights (Coz humans love ’em ) Quick hardware analysis\nA quick analysis of the PCB shows a micro controller(PIC16F726 to be precise) . Q1 seems to be a dual P channel MOSFET ( marked as ISC 6981D ). Q2 is marked AO8808A a dual N Channel MOSFET. The MOSFETs formed an H bridge which drives the “Ultrasonic motor” which I plan to get to run soon. then there’s a few sundry(read boring/uninteresting) components which probably are there for over voltage protection, an LDO, Li-Ion battery charger Etc. (High Res Image of the PCB ).\nThen there seems to be 6 test Points which are conveniently labelled for easy debugging( or hacking I guess!) I’ll probe those and see what they do probably try out a few common baud rates and see what the Micro spits out. There are plenty of test points on the PCB that should include the programming pins for the micro as well.\nThat’s pretty much it for the electronics side of things.\nThen there are other things like the Motor, A AA size Li-Ion battery, a charging coil. The coil probably forms an air core transformer with the charging dock, but I;m still not clear on how it is rectified back in to DC for charging the battery, with so few components and no bulky capacitors on the PCB.\nI’ll probably power up the micro controller and see whats being sent out over the UART. Next on my To-do list would be to get the motor running and after that i would like to check out how the charging subsystem works with the weird air core coil arrangement. The weekend is fast approaching, so this guy should keep me busy for a good part of the weekend.\nSpecial Thanks to Alex for donation 🙂\n","permalink":"https://murli-shenoy.com/posts/electronics-inside-a-philips-sonicare-electric-toothbrush/","summary":"\u003cp\u003eToday a coworker of mine gave me his old Philips Sonicare toothbrush. He said it had stopped charging and would no longer work. That was a good opportunity for a tear down 😉\u003c/p\u003e\n\u003cp\u003eLets see what makes this baby chooch….(As the great man himself said \u003ca href=\"https://www.youtube.com/watch?v=lA0kiYqyBmo\"\u003ehttps://www.youtube.com/watch?v=lA0kiYqyBmo\u003c/a\u003e)\u003c/p\u003e\n\u003cp\u003e\u003cimg alt=\"12562858_10206868876974739_1096742337_o1\" loading=\"lazy\" src=\"/posts/electronics-inside-a-philips-sonicare-electric-toothbrush/images/12562858_10206868876974739_1096742337_o1.jpg\"\u003e\u003c/p\u003e\n\u003cp\u003eThere’s very little to this device. it seems like there’s just a micro controller running the show, like every other product. (there’s more horsepower in a toothbrush these days than an a 50 year old Supercomputer!) it probably does the following tasks( my guesstimate)\u003c/p\u003e","title":"Electronics Inside a Philips Sonicare Electric toothbrush"},{"content":"Last weekend over thanksgiving, I finally found some time to move over my blog to a custom hosted solution over from the old one. I now have a custom WordPress install(this might change soon, as I’m looking at other options, which are more efficient like jekyll ). The blog should now be snappier, also i’m planning to add a few bells and whistles on the backend (git server, host some files etc). On the hardware front, I am currently working on the ESP8266 on adding an Epaper display and a few custom sensors. I’m using a rather interesting and firmware framework called SMING, which is an interesting hybrid between the Arduino framework and native GCC. Sming I feel is still rather nascent, but the developers are working hard on refining it. I plan to finish the e paper display interface this week, and then I can go ahead with finishing the project, something that looks more like a product than a quick hack. I’ve had a few stumbling blocks along the way, which i have put them aside for now.\nIts been a long time dream of mine to build some thing that look more like a store-bought product than something hacked together. This is proving to be a much tougher and more resource intensive than I expected, but I’m being persistent and have been working on and off on it for a while now. Hopefully I will have something cool to show off soon, and will be richer with interesting experiences on developing a product from scratch. Also my Rpi Zero came in this weekend. I played around with it a bit, I’m waiting on some cables to come so I can have a stable setup, the cables from my previous Rpi hack are kinda dodgy and dont seem to work very well, I will post a detailed review on the Zero soon.\n","permalink":"https://murli-shenoy.com/posts/murlis-blog-has-a-new-home/","summary":"\u003cp\u003eLast weekend over thanksgiving, I finally found some time to move over my blog to a custom hosted solution over from the \u003ca href=\"https://murlidharshenoy.wordpress.com/\"\u003eold one\u003c/a\u003e. I now have a custom WordPress install(this might change soon, as I’m looking at other options, which are more efficient like \u003ca href=\"https://jekyllrb.com/\"\u003ejekyll\u003c/a\u003e ).  The blog should now be snappier, also i’m planning to add a few bells and whistles on the backend (git server, host some files etc). On the hardware front, I am currently working on the ESP8266 on adding an Epaper display and a few custom sensors. I’m using a rather interesting and firmware framework called \u003ca href=\"https://github.com/SmingHub/Sming/\"\u003eSMING\u003c/a\u003e, which is an interesting hybrid between the Arduino framework and native GCC. Sming I feel is still rather nascent, but the developers are working hard on refining it. I plan to finish the e paper display interface this week, and then I can go ahead with finishing the project, something that looks more like a product than a quick hack. I’ve had a few \u003ca href=\"https://github.com/SmingHub/Sming/issues/399\"\u003estumbling blocks\u003c/a\u003e along the way, which i have put them aside for now.\u003c/p\u003e","title":"Murli’s blog has a new home"},{"content":"Recently, I got a used Atrix 4g lapdock for 30 bucks off of craigslist. It was a really good deal for a device that packs a USB hub, a 10+ inch LCD a keyboard, a trackpad and also a 10000mAh battery. Supply it with a processor and it can be a full fledged laptop computer. My atrix 2 worked fine with the lapdock. I used it a lot for watching youtube videos and for PDFs.\nThe good thing about the lapdock is that it has everything that is needed to setup a raspberry pi. I had one of the earliest revisions of the raspberry pi which up until now I used as my media file server. And the only was i would interact with it was over SSH since i really hated the mess of wires that would come with setting up the monitor and keyboard for the Pi. The lapdock was a very elegant solution to this problem. it was just a matter of splicing some wires together and some soldering before i would get my very own Rpi Laptop. Here’s the finished product.\nIf you are looking to make one below are some resources.\nHere’s the instructional video from Adafruit that i referred to make this project. do check it out.\nHere’s another blogpost which i think managed to do away with the soldering altogether but you might end up spending some extra money. but is more rugged and sturdy than the home-made cable solution. http://rpidock.blogspot.com/2012/05/raspberry-pi-and-motorola-lapdock.html\nHere are the cables and stuff that you will need for this project.\n1. Micro USB B Male Female M/F Extension Charging Cable\n2. HDMI 1.4 D type Micro HDMI Male to Micro HDMI Female M/F\n3. HDMI Male to Micro HDMI Female Adapter/Converter\n4. Micro USB cable\nYou will also need Soldering iron and some heat shrink tubing for the project. So keep that handy.\nDo let me know how it goes.\nQuestions?? Fell free to post them in the comments below!\n","permalink":"https://murli-shenoy.com/posts/raspberry-pi-laptop/","summary":"\u003cp\u003eRecently, I got a used Atrix 4g lapdock for 30 bucks off of craigslist. It was a really good deal for a device that packs a USB hub, a 10+ inch LCD a keyboard, a trackpad and also a 10000mAh battery. Supply it with a processor and it can be a full fledged laptop computer. My atrix 2 worked fine with the lapdock. I used it a lot for watching youtube videos and for PDFs.\u003c/p\u003e","title":"Raspberry Pi laptop"},{"content":"\ncanon camera teardown, a set on Flickr.\nA couple weeks ago, at work I found a digital camera that was thrown away in the recycle bin, it had a broken LCD and everything else seems to be in good shape. It was a 2.1 Megapixel Shooter so i figured it must really old. On googling I found that it was launched in 2001 and one of the smallest digital cameras of its time. and cost like $600 US! these days you can get a decent DSLR for that price. Check out the review of this device here!\nEnough chit-chat, lets get to the real deal. I wanted to take the sucker apart and see the innards and understand its working. The camera is enclosed in a metal enclosure and could easily take a drop or two without taking much damage. Dissaembly was easy as the entire case was held together by philips head screws. The canon engineers were able to cram in a lot of stuff into a relatively tiny case,about the size of a pack of cards. It even had its own Li-Ion battery with a seperate external charger.\nI have posted the photos of the teardown on my Flickr account. The pictures have elaborate descriptions feel free to browse through them. Feel free to ask any questions in the comments below! Enjoy!\n","permalink":"https://murli-shenoy.com/posts/teardown-of-a-13-year-old-canon-digital-camera/","summary":"\u003cp\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762188646/in/set-72157639457770454/\" title=\"IMG_0685\"\u003e\u003cimg alt=\"IMG_0685\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762188646_b32da2d396_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761836044/in/set-72157639457770454/\" title=\"IMG_0684\"\u003e\u003cimg alt=\"IMG_0684\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761836044_8ddc3021dd_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762185366/in/set-72157639457770454/\" title=\"IMG_0686\"\u003e\u003cimg alt=\"IMG_0686\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762185366_4e3081a0c7_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761664393/in/set-72157639457770454/\" title=\"IMG_0687\"\u003e\u003cimg alt=\"IMG_0687\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761664393_ef122a2997_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762178536/in/set-72157639457770454/\" title=\"IMG_0688\"\u003e\u003cimg alt=\"IMG_0688\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762178536_2bb2542364_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761819764/in/set-72157639457770454/\" title=\"IMG_0689\"\u003e\u003cimg alt=\"IMG_0689\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761819764_f21032f40f_s.jpg\"\u003e\u003c/a\u003e\u003cbr\u003e\n\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761412755/in/set-72157639457770454/\" title=\"IMG_0690\"\u003e\u003cimg alt=\"IMG_0690\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761412755_bf5c53d18d_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762166776/in/set-72157639457770454/\" title=\"IMG_0691\"\u003e\u003cimg alt=\"IMG_0691\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762166776_cd738629df_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761401695/in/set-72157639457770454/\" title=\"IMG_0692\"\u003e\u003cimg alt=\"IMG_0692\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761401695_09d04f66c4_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762151846/in/set-72157639457770454/\" title=\"IMG_0693\"\u003e\u003cimg alt=\"IMG_0693\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762151846_6901dafbd0_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761376895/in/set-72157639457770454/\" title=\"IMG_0694\"\u003e\u003cimg alt=\"IMG_0694\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761376895_bbe946e63c_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761600745/in/set-72157639457770454/\" title=\"IMG_0695\"\u003e\u003cimg alt=\"IMG_0695\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761600745_fbdddf756f_s.jpg\"\u003e\u003c/a\u003e\u003cbr\u003e\n\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761606035/in/set-72157639457770454/\" title=\"IMG_0696\"\u003e\u003cimg alt=\"IMG_0696\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761606035_1a30db59f8_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761609365/in/set-72157639457770454/\" title=\"IMG_0697\"\u003e\u003cimg alt=\"IMG_0697\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761609365_33b2d3a7e9_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761618735/in/set-72157639457770454/\" title=\"IMG_0698\"\u003e\u003cimg alt=\"IMG_0698\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761618735_878cd53c59_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762379476/in/set-72157639457770454/\" title=\"IMG_0699\"\u003e\u003cimg alt=\"IMG_0699\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762379476_5310830c7b_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762383346/in/set-72157639457770454/\" title=\"IMG_0700\"\u003e\u003cimg alt=\"IMG_0700\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762383346_4d220fb8e1_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761628405/in/set-72157639457770454/\" title=\"IMG_0701\"\u003e\u003cimg alt=\"IMG_0701\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761628405_0100bfbb3c_s.jpg\"\u003e\u003c/a\u003e\u003cbr\u003e\n\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761870183/in/set-72157639457770454/\" title=\"IMG_0702\"\u003e\u003cimg alt=\"IMG_0702\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761870183_5ecdb5e61c_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761872943/in/set-72157639457770454/\" title=\"IMG_0703\"\u003e\u003cimg alt=\"IMG_0703\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761872943_d78cc18cec_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761638155/in/set-72157639457770454/\" title=\"IMG_0704\"\u003e\u003cimg alt=\"IMG_0704\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761638155_634a7eb8ff_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762049294/in/set-72157639457770454/\" title=\"IMG_0705\"\u003e\u003cimg alt=\"IMG_0705\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762049294_6e775f8f5c_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11762076234/in/set-72157639457770454/\" title=\"IMG_0706\"\u003e\u003cimg alt=\"IMG_0706\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11762076234_c0f6d49d37_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/11761917733/in/set-72157639457770454/\" title=\"IMG_0707\"\u003e\u003cimg alt=\"IMG_0707\" loading=\"lazy\" src=\"/posts/teardown-of-a-13-year-old-canon-digital-camera/images/11761917733_a92868918a_s.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/sets/72157639457770454/\"\u003ecanon camera teardown\u003c/a\u003e, a set on Flickr.\u003c/p\u003e\n\u003cp\u003eA couple weeks ago, at work I found a digital camera that was thrown away in the recycle bin, it had a broken LCD and everything else seems to be in good shape. It was a 2.1 Megapixel Shooter so i figured it must really old. On googling I found that it was launched in 2001 and one of the smallest digital cameras of its time. and cost like $600 US! these days you can get a decent DSLR for that price. Check out the review of this device here!\u003c/p\u003e","title":"Teardown of a 13 year old canon digital camera."},{"content":"I have a Dual Boot boot system Running Ubuntu 12.04(LTS) and Windows \u0026amp; Home Premium(x64).\nThe other day i was booted into ubuntu and had to use gparted to partition and format a flash drive to use with my Pogoplug-B01. And i by-mistake formatted the windows boot partition . Oops. I restarted my system and could not boot into windows! For me Windows is like a necessary Evil . Its where all my games reside! All for the other programming related stuff i use ubuntu. So i needed to get the windows partition up and running.\nAlso before you go ahead i would recommend you take a backup just in case anything goes wrong by booting into the system by a ubuntu live CD.\nThis can only be used to repair a system where the boot partition is either formatted or is corrupted. This would not work if the main system partition containing the OS itself is damaged.\nStarting Windows Vista Microsoft made the boot partition a separate partition (generally 100MB)from the partition containing the actual OS files.\nStep 1 Get the appropriate WIN 7 recovery Image from here.\nStep 2 Create the CD/DVD or the USB stick(Skip to Method 2 in this Link )\nStep 3 Without the boot sector When you turn on your computer u will get a ‘no Operating system Found’ error . So you will need to set your boot drive to the DVD or the USB drive Depending upon whta media you are using.\nStep 4 Once you Boot into the Repair Disk Hit Startup Repair. If that fixes the issue. you are all set! But for me that was not so Easy. I Selected the Command Prompt Option the type in the following commands and hit enter after each command\ndiskpart\nlist disk\nselect disk (followed by the number of the OS disk; most likely 0)\nlist partition\nselect partition (followed by the number of the Boot partition; most likely the 100-200Mb partition)\nactive\nexit\nStep 5 Now again type\ndiskpart\nlist disk\nselect disk(followed by the number of the OS disk; most likely 0)\nlist partition\nmake Sure there’s a star(*) against the selected boot partition\nthen type format and hit enter. This will format the boot partition to NTFS.\nStep 6 Now to repair the boot partition make the boot partition active by repeating the STEP 4\nnext enter following commands and hit enter after each command.\nbootrec /fixmbr\nbootrec /fixboot\nbootrec /rebuildbcd\nStep 7 Now restart the computer with the recovery media plugged in.\nnow in the recovery options select the ‘Startup Repair’ option. It should b able to fix any other issue with the boot sector and restore it to the optimal state.\nNow Restart the computer and this time remember to unplug the media when the system shuts down.\nHave Fun.\nLet me know how i goes in the comments below! 🙂\nBest of Luck!\nThese Posts Were really helpful:\n[1] http://www.windowsreinstall.com/winre/createfromiso/#.Uhm2oG3tx24\n[2] http://www.selectrealsecurity.com/fix-windows-startup\n[3] http://windows.microsoft.com/en-US/windows-vista/What-are-system-partitions-and-boot-partitions\n[4] http://windows.microsoft.com/en-us/windows7/create-a-system-repair-disc\nselect partition (followed by the number of the OS partition; most likely the largest partition)\n","permalink":"https://murli-shenoy.com/posts/restoring-the-windows-boot-partition/","summary":"\u003cp\u003eI have a Dual Boot boot system Running Ubuntu 12.04(LTS) and Windows \u0026amp; Home Premium(x64).\u003c/p\u003e\n\u003cp\u003eThe other day i was booted into ubuntu and had to use gparted to partition and format a flash drive to use with my \u003ca href=\"http://archlinuxarm.org/platforms/armv6/pogoplug-v3oxnasend-life\"\u003ePogoplug-B01\u003c/a\u003e. And i by-mistake formatted the windows boot partition . Oops. I restarted my system and could not  boot into windows! For me Windows is like a necessary Evil . Its where all my games reside! All for the other programming related stuff i use ubuntu. So i needed to get the windows partition up and running.\u003c/p\u003e","title":"Restoring the Windows Boot Partition….."},{"content":"I just started playing around with the TI Stellaris Launchpad a couple of days ago.\nThe Launchpad is a pretty powerful little dev board. It has ARM Cortex-M4F core at it heart. The really awesome thing is that there’s a Full fledged debugger built-in which makes it a really good board to start with ARM micros.\nI was fiddling with the UART trying to setup two way communication with the micro. so i started out with the uart_echo project included in the Stellarisware bundle.\nThe uart_echo code works with the UART0 of the micro and i wanted to get it running on the UART1, Sound simple right? But for a Newbie to this micro-controller it might be a bit difficult. That was what happened it took some amount of digging around the internets and the documentation to get the code to do what i wanted but finally it started working\nHere’s what i ended up doing. First i reconfigured all the I/Os the UART1 Pins can be used either on PB0,1 or on PC4.5. I used the PB0 and PB1 pins. changed the code in all the other relevant places in the main code, tried running the code . I got the “Enter Text” messgae on the terminal. It means the Tx was working fine. but i could get a echo back from the micro. The uart_echo uses the uart receive interrupt which was not being triggered. So i needed to get the interrupt triggered when the data comes in on the RX pin. by the way i did try the echo function running in the while loop and that confirmed that the physical connection was good and that the code was working.\nI stumbled upon a forum post by another person facing similiar problems where he suggested that i make changes to the interrupt vector table in the startup_ccs.c file i simply replaced the IntDefaultHandler with the UART1IntHandler which is the interrupt handler for UART1 and like magic the code started working! Here’s the final Ti Code Composer studio v5.2 project. You can Import the code directly into CCS using the import option.\nPlanning to get the PWM working now…..will post on it soon…\n","permalink":"https://murli-shenoy.com/posts/playing-with-the-uart-on-the-ti-stellaris-launchpad/","summary":"\u003cp\u003eI just started playing around with the TI Stellaris Launchpad a couple of days ago.\u003c/p\u003e\n\u003cp\u003eThe Launchpad is a pretty powerful little dev board. It has  ARM Cortex-M4F core at it heart. The really awesome thing is that there’s a Full fledged  debugger built-in which makes it a really good board to start with ARM micros.\u003c/p\u003e\n\u003cp\u003eI was fiddling with the UART trying to setup two way communication with the micro. so i started out with the uart_echo project included in the Stellarisware bundle.\u003c/p\u003e","title":"Playing with the UART on the TI Stellaris Launchpad."},{"content":"\nMaker Faire 2013, a set on Flickr.\nThe Bay Area Maker Faire 2013 Day 1\n","permalink":"https://murli-shenoy.com/posts/maker-faire-2013/","summary":"\u003cp\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753611896/in/set-72157633516082843/\" title=\"2013-05-18_14-27-05_477\"\u003e\u003cimg alt=\"2013-05-18_14-27-05_477\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753611896_4bd9fb112f_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753611814/in/set-72157633516082843/\" title=\"2013-05-18_14-27-20_231\"\u003e\u003cimg alt=\"2013-05-18_14-27-20_231\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753611814_536afdc1af_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752487123/in/set-72157633516082843/\" title=\"2013-05-18_14-27-29_505\"\u003e\u003cimg alt=\"2013-05-18_14-27-29_505\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752487123_79858c90cb_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752485305/in/set-72157633516082843/\" title=\"2013-05-18_14-29-01_991\"\u003e\u003cimg alt=\"2013-05-18_14-29-01_991\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752485305_81c02a28b8_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753611700/in/set-72157633516082843/\" title=\"2013-05-18_14-30-37_112\"\u003e\u003cimg alt=\"2013-05-18_14-30-37_112\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753611700_6a02b36d3f_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753611646/in/set-72157633516082843/\" title=\"2013-05-18_14-31-18_99\"\u003e\u003cimg alt=\"2013-05-18_14-31-18_99\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753611646_5fb8cecca2_s.jpg\"\u003e\u003c/a\u003e\u003cbr\u003e\n\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752486923/in/set-72157633516082843/\" title=\"2013-05-18_14-31-21_721\"\u003e\u003cimg alt=\"2013-05-18_14-31-21_721\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752486923_f0fcf9217f_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753611508/in/set-72157633516082843/\" title=\"2013-05-18_14-31-26_617\"\u003e\u003cimg alt=\"2013-05-18_14-31-26_617\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753611508_b2a67937b7_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753611444/in/set-72157633516082843/\" title=\"2013-05-18_14-31-56_600\"\u003e\u003cimg alt=\"2013-05-18_14-31-56_600\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753611444_400787d72e_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752486733/in/set-72157633516082843/\" title=\"2013-05-18_14-32-31_553\"\u003e\u003cimg alt=\"2013-05-18_14-32-31_553\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752486733_06499a1129_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753609354/in/set-72157633516082843/\" title=\"2013-05-18_14-32-36_614\"\u003e\u003cimg alt=\"2013-05-18_14-32-36_614\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753609354_4032355fdc_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752494637/in/set-72157633516082843/\" title=\"2013-05-18_14-34-38_91\"\u003e\u003cimg alt=\"2013-05-18_14-34-38_91\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752494637_b2b248a1c6_s.jpg\"\u003e\u003c/a\u003e\u003cbr\u003e\n\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753619002/in/set-72157633516082843/\" title=\"2013-05-18_14-34-45_145\"\u003e\u003cimg alt=\"2013-05-18_14-34-45_145\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753619002_0231c3d7b9_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752494495/in/set-72157633516082843/\" title=\"2013-05-18_14-36-51_81\"\u003e\u003cimg alt=\"2013-05-18_14-36-51_81\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752494495_6448fe14a3_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752494429/in/set-72157633516082843/\" title=\"2013-05-18_14-39-59_917\"\u003e\u003cimg alt=\"2013-05-18_14-39-59_917\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752494429_c4c57a22eb_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753618788/in/set-72157633516082843/\" title=\"2013-05-18_14-43-55_132\"\u003e\u003cimg alt=\"2013-05-18_14-43-55_132\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753618788_c86f584d44_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752494301/in/set-72157633516082843/\" title=\"2013-05-18_14-43-59_170\"\u003e\u003cimg alt=\"2013-05-18_14-43-59_170\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752494301_81a289a25c_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753618678/in/set-72157633516082843/\" title=\"2013-05-18_14-45-20_56\"\u003e\u003cimg alt=\"2013-05-18_14-45-20_56\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753618678_5b9aa36fdc_s.jpg\"\u003e\u003c/a\u003e\u003cbr\u003e\n\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753618622/in/set-72157633516082843/\" title=\"2013-05-18_14-45-23_854\"\u003e\u003cimg alt=\"2013-05-18_14-45-23_854\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753618622_76470db717_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753618560/in/set-72157633516082843/\" title=\"2013-05-18_14-45-30_161\"\u003e\u003cimg alt=\"2013-05-18_14-45-30_161\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753618560_aa4cae39d6_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753618472/in/set-72157633516082843/\" title=\"2013-05-18_14-47-21_393\"\u003e\u003cimg alt=\"2013-05-18_14-47-21_393\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753618472_dbda952b53_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752493933/in/set-72157633516082843/\" title=\"2013-05-18_14-50-42_733\"\u003e\u003cimg alt=\"2013-05-18_14-50-42_733\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752493933_39affc7470_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8752493849/in/set-72157633516082843/\" title=\"2013-05-18_14-53-39_399\"\u003e\u003cimg alt=\"2013-05-18_14-53-39_399\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8752493849_cdd970297c_s.jpg\"\u003e\u003c/a\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/8753618308/in/set-72157633516082843/\" title=\"2013-05-18_14-53-52_636\"\u003e\u003cimg alt=\"2013-05-18_14-53-52_636\" loading=\"lazy\" src=\"/posts/maker-faire-2013/images/8753618308_80648d37ce_s.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"http://www.flickr.com/photos/murlidhar/sets/72157633516082843/\"\u003eMaker Faire 2013\u003c/a\u003e, a set on Flickr.\u003c/p\u003e\n\u003cp\u003eThe Bay Area Maker Faire 2013 Day 1\u003c/p\u003e","title":"Maker Faire 2013"},{"content":"A couple of days ago i received in my order of Philips SHH7810 in-ear headset from Flipkart.com. They delivered it in like 2 days as promised. I love their service and sometimes the price is also very reasonable as compare to brick-and-mortar stores,which was true in this case.I got it for 985 INR,which i think was pretty reasonable.\nThe SHH7810 in my opinion is one of the cheapest and quality headsets with inline microphone that money can buy,I had done some research prior to finalizing this one, i coudn’t find any decent brand(aka sennheiser,skullcandy,sony,etc) earphones with inline mic and call.answer button,there was one from skullcandy around the 1k INR range but i was using the skullcandy ink’d for the past 8 months which was very similiar,I wanted some change and this had to be it.\nIt arrived in a nice little flipkart bubble wrap lined mailer bag.The contents inside were nicely protected and did not show any signs of stress from the shipping .\nI sometimes hate the amount of packaging that comes with the earphones,there’s too much plastic and takes a lot of effort to open it up. 😦\nThe contents of the package include the standard fare 3 different sizes silicone ear plugs. And an interesting compatibility adapter that allows the headset to work with almost all of the commonly available phones with 3.5mm standard connector\nI had a Motorola so i did not need the adapter!\nPlugged it into my atrix 2 ,there were no issues ,the headset was recognized . Tried playing some tunes and sounded good and was stereo made some calls.I was able to pick up calls with the call/end button,Mic also worked good.\nthe thing that i hate about this headset is the inline volume control! I was fooled by the images on flipkart and other places! I had thought it was a push button based solution,similiar to the ones found in the inbox headsets that come with phones.Sigh! it was just a crappy volume slider which instead of sending a command to the phone to change the system volume of the phone just fiddles with the signal by changing the inline resistance which is a BAD way to do it. And from past experience is one very big potential point of failure! .In headphones these things are the first to fail. I hope that Philips has designed it well enough ,and it lasts atleast 6 months without failure!. If the headset lasts 6 months of rough use (or rather abuse!) i would call it well worth the money!\nMoving on to the sound quality of these phones,the overall sound quality is good for the price. The bass i feel sometimes is as good as Sennheisers and the Skullcandys from a higher price range.Sometimes though i feel the bass is too much and it overpowers the mids ,and the mids get supressed.The Highs and decent and very seldom tend to crack very very slightly only if you listen with a very keen ear,you wont notice it otherwise!.Now there is a very important thing about these phones that i found about as i used them,You need to get the correct fit to understand the true capability of the drivers. Which is somewhat difficult sometimes since the design is a bit weird with the angled drivers and all,which philips claims to deliver better sound directly to the ear drums.Frankly,i found it a bit uncomfortable to wear,might be a new earphone thing and might take some time for my ears to get used to. But not as comfortable as my first pair of in-ears my JVC fx-33Bs! I really Miss them!\nOne thing i really like about the headset is ,it has small bumps on the left earpeice. This helps you to recognize the left and the right earphone even in the dark. This is\nFinal Words: Really good bass,OK mids and highs.OK build quality,Crappy volume control,takes some time getting used to the fit,great compatibility with almost all modern smart phones on the planet(including the iPhone!).Great value for the Price!\nLet me know what you think about it in the comments below!! 🙂\nUpdate:Tested the headset with a a bunch of phones here’s the result\nPhone Result\niPhone Works pretty Well.\nSamsung Galaxy S i9003 Worked well. Without the bundled adapter. (The adapter was meant for samsung ,nokia and sony ericsson phones!)\nSony Xperia S Did Not Work ,even with and without the bundled adapter a ‘headset incompatible ‘message shows up!.I was expecting it to work.\nThe package did not mention anything about this! They should’ve specify the exact phone models that are compatible!\n","permalink":"https://murli-shenoy.com/posts/philips-shh7810-in-ear-headset-for-mobile-phone-review/","summary":"\u003cp\u003eA couple of days ago i received in my order of \u003ca href=\"http://www.flipkart.com/philips-shh-7810-in-the-ear-headset/p/itmd4usy72hf5ta7?pid=ACCD4URYU52E7BXZ\u0026amp;ref=1b8b29de-29c6-4fda-b117-d32a5802753e\"\u003ePhilips SHH7810 in-ear headset\u003c/a\u003e from Flipkart.com. They delivered it in like 2 days as promised. I love their service and sometimes the price is also very reasonable as compare to brick-and-mortar stores,which was true in this case.I got it for 985 INR,which i think was pretty reasonable.\u003c/p\u003e\n\u003cp\u003eThe SHH7810 in my opinion is one of the cheapest and quality headsets with inline microphone that money can buy,I had done some research prior to finalizing this one, i coudn’t find any decent brand(aka sennheiser,skullcandy,sony,etc) earphones with inline mic and call.answer button,there was \u003ca href=\"http://www.flipkart.com/skullcandy-s2indy-033-headset/p/itmd8gxyrws6zqtu?pid=ACCD8GXYHG68PHGF\u0026amp;ref=38cc9633-8554-4daa-9cd4-3f62abd9d836\"\u003eone\u003c/a\u003e from skullcandy around the 1k INR range but i was using the skullcandy ink’d for the past 8 months which was very similiar,I wanted some change and this had to be it.\u003c/p\u003e","title":"Philips SHH7810 In-ear headset for Mobile Phone review"},{"content":"Motorola launched the atrix 2 in india late last month. Almost six months after they launched it in the US.\nIt seemed like a good vfm phone given the market price of around 22,000 INR and the many positive reviews all around the internet made it seem like an awesome buy!!!\nSo i thought i should check it out.I ordered it,from probably india’s answer to amazon flipkart. it arrived 3 days post order. Packed snuggly in couple of layers of bubble wrap which i enjoyed popping! :P.\nLets open it up and check it out!\nOverview\nThe atrix2 comes with pretty standard stuff inbox. A 2gig micro sd. A pair of earphones , that i will probably never use! A data cable. A charger with a USB socket. So that you can directly plug in your datacable into the charger and it becomes the charging cord! Most manufacturers now-a-days ship phones with a female usb so that people can just plug in the datacable itself and charge their phones!! I think its cool! The battery that comes with the phones a li-po battery with a capacity of around 1785mAh max(1735 mAh Typ.)! Thats awesome and reviews everywhere say that the large battery really helps a lot in keeping the phone alive and kicking for like more than a day, and with super heavy use! Infact the big battery and the dual core processor were the biggest factors that made me go for this phone!\nHardware\nAs i said the phone is powered by a dual core processor. Infact the phone is based on the TI OMAP4430 chipset with 2 arm-cortex A9 cores!! And the gpu is a powervr SGX540. The hardware was able ti handle 3d games pretty easily! I tested the 3D capabilities with the bundled EA games that came free with the phone. Dead space looked stunning and i was able to play the game without a single frame being dropped!\nI also ran a few benchmarks with the Quadrant Standard Benchmark. And It scored a decent 1756. and Even bettered the galaxy nexus in the 3D scores.\nThe Sound quality was decent.The true Quality was not evident with the bundled Headset. But Sounded good on my Skullcandy Inkd Ear Buds.\nThe Display Is a qHD 960×540 TFT. The resolution and Pixel density is awesome .The colors appeared a bit yellow. Sunlight Visibility was okay. Overall the display is ok ,but a better quality display would have been much appreciated.\nThe Phone also Supports USB HOST.But i haven’t tried it out yet .Will be trying it out soon. And i will post about it soon,as soon as i’m done.There’s also a mini HDMI Jack for connecting to a monitor or a TV set. The cable is not bundled with the handset.\nThere are two camera one on the front for video chat and another on the back .The rear Camera has a 8Mp Sensor and has a single LED flash.Low Light performance is ok. Better than Most cameras. The images can be shot in various modes and at various resolutions. I liked the widescreen Image option Where the image is shot at a widescreen aspect ratio. and the resolution is around 6Mp.Full HD Videos can be Shot With the camera.Here’s a Sample of a Video that i took with the camera. (Thats Hemanshu Playing the bass Cover for Billy jean in the video).Videos Came Out Pretty good at 1080p and even at lower resolutions.Even at night the videos Came out pretty decent.Infact I think the videos came out better than the Images shot in low light!\nSoftware\nThe Phone Comes with android gingerbread 2.3.6 out of the box. And a ICS update for the Asia pacific model (the models available in india) is expected in 3q 2012. That’s actually pretty late considering that most devices will be getting their ICS updates in 2q and there are already devices running Android 4.0 in the market!\nMoto phones are bundled with their Custom version of the Android UI called MOTOBLUR,which i really like ,Much better than Samsungs Touchwiz UI which Is more like a clone of Apple’s UI. and even HTC SENSE which i don’t like at all.\nThe default Music Player App is Actually great in some aspects. It fetches the lyrics asn album art for you as the song is being played. It does not save the lyrics though hence to enjoy the lyrics you will need internet connectivity when the song is being played.It uses Tunewiki for fetching the song info.\nThere also this thing called the Universal inbox.Its basically a Place where all your unread Fb messages and texts are displayed in a single widget.Kinda Cool but haven’t used it much yet.\nThe Phone has on-board storage of like 8Gb. But it cant be used to store data files. Only application data Can be stored.Rooting can probably Solve this ‘issue’ and allow the on-board storage to be used more efficiently.\nThe Lock Screen interface is nice and i really like it.\nThere is Also the motorola phone portal that allows to sync your phone with your PC not only over USB but alos using wifi!! That’s actually Neat! You can manage all your data ,contacts and message .Using a simple Browser Interface. Internet explorer is the only browser supported to allow data Management though! :(.Other things such as Contacts and Messages can be managed with virtually any browser.\nThe Dialer interface and contacts app Kinda Sucks and takes time getting used to. And Unlike in HTC devices the Contacts from different sources such as facebook,twitter and your phone book are not merged but appear as separate contacts! WTF??. The Contacts App implementation of HTC was way better in this aspect!.It used to give me contact match suggestion and it even merged contacts from various sources automatically. So that if a person in on FB,twitter and Also is in my phone book.It appears as a single Contact. Instead of Multiple contacts!!!\nYou get 5 Customizable home screens.The Other UI elements are pretty much standard Android nothing much to add in this department!\nDesign\nThe Size of the Phone is perfect and Fits snuggly into your palms. The back of the phone is Rubberized and has a fabric like texture to enhance the grip.\n4 standard Android Keys are present at the bottom of the LCD.\nThe Key placement should is a bit too close to the edges and would have been better if it was placed a bit higher. The Keys get accidentally activated when typing with both hands. And can interfere and reduce the typing speed drastically!. I strongly recommend some sort of body cover for this phone.The Phone Seems Slippery,Especially when using it single-handed.I used a silicon jelly case from amzer. It improved the usability drastically!.And Also got a more comfortable grip on the phone.\nThe Earphone jack is the Worst part of the design,i feel. I tends to scratch the surface of the earphone Plug . I tried it with a couple of earphones. And the Plugs of both the Earphones were scratched badly!.I really hate it very much!\nThe rocker keys for the volume and the camera key on the side of the device are wedge shaped and have a sharp edge.Its a bit difficult to press them due to the shape. But i guess one can live with that as its not that bad actually!\nBottom line: The Real Good stuff :battery life ,qHD display, awesome Hardware,Decent Camera. The Let Downs The Silly Earphone Socket,the Display Is a TFT-LCD(Blacks are usually just grays,If you own a phone with an AMOLED display You will Find the display weird because of the poor contrast ratio),The Phone’s Design really makes typing with both hands in landscape Mode difficult.The rocker keys at the side could have been better designed,the phone lacks grip and hence neccesitates a body cover fro the phone\nThis Video Review Helped me a lot in making my decision but i think they didn’t cover the downsides of the device well .\nDisclaimer: All the views expressed are totally based on my personal experiences and i am not affiliated to nor was paid by any of the organisations/companies mentioned in the above post.\n","permalink":"https://murli-shenoy.com/posts/motorola-atrix2-reviewed/","summary":"\u003cp\u003eMotorola launched the atrix 2 in india late last month. Almost six months after they launched it in the US.\u003c/p\u003e\n\u003cp\u003eIt seemed like a good vfm phone given the market price of around 22,000 INR and the many positive reviews all around the internet made it seem like an awesome buy!!!\u003c/p\u003e\n\u003cp\u003eSo i thought i should check it out.I ordered it,from probably india’s answer to amazon \u003ca href=\"http://www.flipkart.com/motorola-atrix-2-mobile-phone/p/itmd7bnagfd4ywcd?pid=MOBD7BN6MWQR7CRP\u0026amp;_l=j9Xfifej1tnSUjNow6B3Vw--\u0026amp;_r=ivemT_qRIQVKCnOLqiJ9PA--\u0026amp;ref=f8c1c794-37df-4b76-a4b6-3258b8bea8d6\"\u003eflipkart\u003c/a\u003e. it arrived 3 days post order. Packed snuggly in couple of layers of bubble wrap which i enjoyed popping! :P.\u003c/p\u003e","title":"Motorola Atrix2 reviewed"},{"content":"I had Received a free Coupon from Dangerous Prototypes as a part of their Free PCBs Contest.I chose to get the Bus Blaster PCB. Since i was really needed a JTAG debugger my lpc1768 blueboard. Just Completed the Build. Check it out! Soldered the FT2232 using the drag soldering method.Had to remove some stubborn solder bridges formed during the soldering of the fine pitch QFP using a razor blade! Thanks Ian and Dangerous Prototypes! 🙂\nUPDATE: Here are some More Pics of the Bus Blaster!!\nThe Dangerous Prototypes Sticker goes well with the Navy Blue Lid of my Laptop! ","permalink":"https://murli-shenoy.com/posts/206/","summary":"\u003cp\u003eI had Received a free Coupon from \u003ca href=\"http://dangerousprototypes.com/\"\u003eDangerous Prototypes\u003c/a\u003e as a part of their Free PCBs Contest.I chose to get the Bus Blaster PCB. Since i was really needed a JTAG debugger my \u003ca href=\"http://shop.ngxtechnologies.com/product_info.php?cPath=21\u0026amp;products_id=65\"\u003elpc1768 blueboard\u003c/a\u003e. Just Completed the Build. Check it out! Soldered the FT2232 using the drag soldering method.Had to remove some stubborn solder bridges formed during the soldering of the fine pitch QFP using a razor blade! Thanks Ian and Dangerous Prototypes! 🙂\u003c/p\u003e","title":"Dangerous Prototypes Bus Blaster Build"},{"content":"RGB LED strips such as this are available for a low price.They are generally bundled with a IR controller and a power supply to power the LEDs and to change the color ,display various colour sequences etc.The IR Receiver is similiar to those used in TV and requires line-of-sight for reliable operation . I wanted the strip to be Controllable via a PC or a Mobile Phone.So I decided to make my own RGB LED strip Controller and to enable wireless control i used Bluetooth technology.The device can be controlled using a PC or a mobile phone with Bluetooth having a suitable graphical user interface.\nThe Hardware needed for this build is pretty simple and uses commonly found devices and may be salvaged from old electronics.\nAtmega8L-8PU 8-bit AVR microcontroller LM1117-3.3 3.3V LDO regulator IRF640 N-Channel MOSFET(salvaged from an old Uninterrupted Power Supply-Thanks Kushal for that Dead UPS! ) Connecting wires ,Berg strips,etc. 12v 1A+Wall wart. The Firmware for the ATmega8L micrcontroller was developed with Arduino 0023 and also with Arduino 1.0 (Can be downloaded for your OS of choice from HERE).The GUI for the Windows PC was Developed using the GTK+ toolkit using the python bindings available via pyGTK(Get it from here).The GUI was designed for running on nokia s60 devices using pyS60.\nThe arduino Firmware\nThe arduino is an awesome prototyping platform.Churning out prototypes from Ideas is very fast since all the hardware and other functions are pretty much abstracted out and only the Application Logic needs to be implemented.\nThe Firmware performs the following basic functions.Handle the communication routines,Control the LED brightness for each of the Colors RED,GREEN and BLUE and also be able to display the various sequences of colors of light.\nI have a Arduino Duemilanove that came with an Atmega328P processor onboard.The Atmega 328P would have been an overkill for this project so i decided to replace it with an Atmega8L.The mega8 has only 3 v/s 6 PWM channels and 8K v/s 32K of flash program memory of the mega328.To verify the firmware I set up a simple testbench with three LEDs one each of RED GREEN and BLUE LEDs plugged into a breadboard connected to the Digital pins 9,10,11 of the arduino.These Correspond to the PWM Pins on the atmega8. The Communications with the controller was tested with the standard serial port given by the FTDI interface of the arduino.\nOnce The test bench was setup I could move on to Actually Writing the Firmware.The Setup section consists of all the PWM pins being set as Output and the Serial Port opened to Communicate at 9600 Baud.The Main while Loop has a Non-blocking delay section in which the Functions are updated at a User changeable delay.The more the delay the more slowly the color transition takes place and viz.This is necessary because if a delay is not present then the transitions would be so fast that it would appear as if the LEDs are blinking.I have NOT used the default delay function of the arduino library because of it blocking nature(Here’s a good article about Non-blocking code).The delay would block the processor by executing a number of instructions with a known execution time to get the specified time delay and only then execute the next instruction.This blocking delay would cause problems when data arrives at the serial port and the processor is busy executing the delay.Hence the data will be missed by the processor or will be processed only when the delay loop completes execution thus introducing lags between the user giving input and the suitable function being executed.Non-blocking Delay is hence used to prevent these problems and to provide reliable communication.And Precisely for this reason I have avoided Blocking codes in my Firmware.\nThe CellPhone GUI\nThe Cellphone GUI is a pyS60 script with five consecutive dialog boxes for mode selection,red value,green value,blue value and the update delay value respectively.The mode selection selects one of three modes.Mode 0 is the default mode will fire up if no bluetooth device is connected for control .In this mode the entire colour spectrum is traversed starting from red end of the spectrum.The transition goes on in a infinte loop.Mode 2 is a mode where each color namely Red,Green,Blue and White Respectively “breathe” i.e. the intensity of each color goes from zero to maximum and back to zero.Check out the Video to see it in action.The Mode three is the Color Chooser Mode. In this mode the User can choose the color.Set the value of the respective color from 0 for completely off to 255 for fully bright.\nAlso the Update delay can be set in milliseconds.This is used for setting the Delay Between Each color transition.the more the dealy the more slower will be the colour change. An update delay of around 5 to 20 milliseconds has a pleasing effect.\n[Screenshot]The Pys60 Script Running on my S60 3rd Edition Nokia N78.\nThe PC GUI.\nThe PC gui was created Using PyGTK and UImanager Tools for GUI Creation. The PC GUI runs well on Windows (and probably also on Linux).I have tested it on my Windows Seven Home Premium 64-bit laptop .For Running the Application on Linux Small Amount of changes will have to be made ,Like changing the serial port label(on linux the PORT variable would be something like dev/ttyUSB0) etc. But other than that it would work fine on linux too.The GUI has three sliders for Color selection and a Bunch of radio Buttons for Mode selection.The Sliders are active only in the color selection mode.Check out the Source code included in the Zip file attached\n[Screenshot]The Python Gui running on A win7 Home Premium x64 Machine\nHardware Design\nthe Hardware basically consists of a Atmega8L Microcontroller (with an Arduino Bootloader on-board which i have included in the sources.zip file) and three IRF640 N-channel MOSFETs ,One Each for Driving Each Color on the RGB LED strip .There’s also Lm1117 3.3V power regulator for powering up the Logic and a Berg connector for connecting the RX,TX,GND and VCC lines of the Bluetooth Module with the Atmega.I did Not make a schematic since i did not want to etch a PCB.Instead i just built the entire circuit on a perf-board and used flexible wire to build the circuit.The Entire Circuit is designed to be powered by an 12V DC Supply.I checked the Power Consumption of the entire circuit with a Multimeter and it was found to be around 1Amp.I used a 12v 2 Amp SMPS based supply.\nI made My prototype on a perfboard here’s a Pic of the Top Side.\nAnd the Bottom Side Working on a PCB using toner tranfer technique to finalise the prototype. All the Python Source Codes and the Hardware schematics and the Layout Diagrams in Eagle Format are included in the attached Zip File .Feedback is appreciated!(Note:a ULN2803 and a 7805 are some extra components on the PCB shown above that i tried out during testing.But are not necessary in this circuit).\nHere are some pics of the project in action.\nDownload all the required Source codes and the hardware design files from here.\nUPDATE: Uploaded all the source Code to github\n","permalink":"https://murli-shenoy.com/posts/bluetooth-controlled-rgb-led-strip/","summary":"\u003cp\u003eRGB LED strips such as \u003ca href=\"http://www.ebay.in/itm/5M-5050-RGB-LED-Strip-Light-IR-Remote-Control-Power-/170628672196#ht_3439wt_990\"\u003ethis\u003c/a\u003e are available for a low price.They are generally bundled with a IR controller and a power supply to power the LEDs and to change the color ,display various colour sequences etc.The IR Receiver is  similiar to those used in TV and requires line-of-sight for reliable operation . I wanted the strip to be Controllable via a PC or a Mobile Phone.So I decided to make my own RGB LED strip Controller and to enable wireless control  i used Bluetooth technology.The device can be controlled using a PC or a mobile phone with Bluetooth having a suitable graphical  user interface.\u003c/p\u003e","title":"Bluetooth Controlled RGB LED strip"},{"content":"Bluetooth has become Ubiqutios these days Bluetooth Wireless technology is present is Most mobile phones today as well as in laptops and in desktop PCs.And If your PC or laptop doesn’t have it then you can get a Bluetooth USB dongle for cheap(like 2-3$ )!\nWouldn’t it be interesting if your mobile phones /PCs could talk to your Micro-controller Projects??\nLets find out how to add Bluetooth capability easily to your existing Micro-controller projects with out many hardware or software changes.\nBluetooth has many ‘profiles’ for communication with various kinds of devices.The profile in which we will be interested in is the Serial Port Profile or SPP for short.This profile simply emulates a standard Serial port over a wireless bluetooth link.\nI was working on a arduino project and wanted to eliminate the wired connection to the arduino form my laptop.The laptop had a GUI running which sent data over a serial COM port to the arduino.I got a Bluetooth module from Lamington road,Mumbai for around 850 INR. You could find it for less on ebay or something.The model number of the bluetooth module is AUBTM-20 .Its a Class 2 Bluetooth SPP module (Class 2 meaning that its range is around 10 meters/ 30 feet).\nI added a relimate connector to make it easy to connect it a breadboard or to connect jumper wires.I had the following connections on the module taken to the connectorGND,VCC and the RX and TX connections of the serial port.\nStep one : Test the module\nJust power up the Bluetooth module(I Fed in power to the Bluetooth Module from the 3.3v output of my arduino ) and scan the bluetooth devices on your PC/laptop.If everything’s done correctly you will be able to find a bluetooth device named AUBTM-20 or something simliar.You will be asked for a pairing code in case of the above model (AUBTM-20)it is 8888 but it might be different if you are using a bluetooth module from another vendor.On my WINDOWS 7 Laptop it showed up as “AUBTM-20” under devices and printers.\nRight Click on the device name in the devices and printers folder under the hardware tab .You will find a Standard Serial over Bluetooth Link and the COM port number writeen in brackets. Note down the COM port number.This completes the Basic test.\nStep Two: Verify The COM link.\nyou will need to verify if you are able to send and receive data over the serial port to be able to use the device in your project for that. I used the FT232RL USB to serial converter chip on-board the arduino. But remember to remove the ATmega processor chip from the socket.(You’re out of luck if you have one of those SMD versions of the arduino 😦 .In this case you will need to get hold of a 3.3V power source such as the lm1117-3.3 and a FT232RL breakout board from here or here ) before you connect the bluetooth module to the arduino. Now Connect the RX line of the Bluetooth module to the TX line of the FT232RL module or you arduino DIgital Pin 1 and the TX line to the RX line of the module or to that of the arduino.\nNow open a terminal application such as TeraTerm (You can download it from here) select the serial port on which you connect your arduino/FT232 module(you can get the com port number of the FTDI device in the device manager under COM ports -\u0026gt; USB serial Port).Open a terminal with the COM port number of the The FTDI device and set the baud rate to 9600 ,8bit -data,Parity- none,1 -stop bit,Flow control -None.\nNow open another COM port,this time with the for the serial COM port of your bluetooth device that you had noted down in the first step. The settings of this COM port will also be the same as above FTDI device. IF all the connections are proper and the link is established then anything you type in the FTDI COM terminal should appear on the Bluetooth COM terminal and vice-versa\nThe +CON:1 is something that the Bluetooth module gives out on the COM port whenever a device is connected .This Proves that the device can successfully communicate over the serial port\nStep Three: Finally connecting the Bluetooth module to the Micro-controller.\nHere’s a quick arduino script to verify everything’s fine .\nvoid setup() { Serial.begin(9600); // open the serial port at 9600 bps: }\nvoid loop() { if( byte( Serial.read() == \u0026lsquo;a\u0026rsquo; )) { Serial.print(\u0026quot;\\nHey!\u0026quot;); // print Hey } }\nJust open the arduino IDE and open the serial terminal.Set the COM port number that you noted down in the First Step and the baud rate to 9600. Just type an “a” without the quotes in the terminal and you should get a reply with a ‘Hey!’.A word of caution the Bluetooth module works at the CMOS voltage range of 3.3V and can take only upto 3.7v max so while interfacing with TTL level devices such as the ATmega8/168/328 of the arduino level conversion will be required (check out this app note from NXP).I chose to use the 3.3v Level Atmega8L instead since the device can work at 3.3V no level conversion would be required.This is the final device that i made uses the LM1117-3.3 as the power regulator to regulate the 12v from the wall wart.\nFor microcontrollers such as LPC1768 and LPC2148 which run at 3.3v levels no level conversion or modification would be required at all.All that would be needed to be done is to connect the rx,tx and the ground lines of the Microcontroller to the Bluetooth module and you would have a Bluetooth enabled microcontroller project!\nThe board was first designed with the Atmega8 then i added the 3.3v regulator and switched over to the Atmega8L.The Mosfets and other devices onboard are for another project that i’m currently working on.Will Post about the project in my next post.Post in the Comments below what you think about it ! ","permalink":"https://murli-shenoy.com/posts/adding-bluetooth-to-your-microcontroller-projects/","summary":"\u003cp\u003eBluetooth has become Ubiqutios these days Bluetooth Wireless technology is present is Most mobile phones today as well as in laptops and in desktop PCs.And If your PC or laptop doesn’t have it then you can get a Bluetooth USB dongle for cheap(like 2-3$ )!\u003c/p\u003e\n\u003cp\u003eWouldn’t it be interesting if your mobile phones /PCs could talk to your Micro-controller Projects??\u003c/p\u003e\n\u003cp\u003eLets find out how to add Bluetooth capability easily to your existing Micro-controller projects with out many hardware or software changes.\u003c/p\u003e","title":"Adding Bluetooth To your Microcontroller projects"},{"content":"Just a Simple code snippet that allows you to send a byte over a 8-bit wide parallel bus when using 32 bit devices such as those based on the ARM architecture.\nWhile programming AVRs this usually would suffice to send a BYTE over a parallel 8-bit wide port.Here’s an avr-gcc example\nPORTC = data;\nBut with the a 32-bit microcontroller For example the LPC1768 from NXP.\nEach port is 32 bits wide and in order to send a byte over an 8-bit section of the 32 bit wide ports\na write to the PIN register of the respective port doesnt work.The Arm cortex-m3 has registers called SET,CLR,MASK and PIN for each of the ports.The purpose of the registers is pretty obvious and for more info refer to the datasheet of the LPC1768 .\nnow in order to send an 8 bit data over a section of the port beginning at byte number 19\nLPC_GPIO2-\u0026gt;FIOSET |= (data \u0026laquo; 19);\ndata ^= 0xFF;\nLPC_GPIO2-\u0026gt;FIOCLR |= (data \u0026laquo; 19);\nsends the data over the 8 bit section of port 2 beginning from pin 19 to pin 26 of the LPC1768.\n1.First the pins corresponding to all the ones present in the 8-bit data are set.\n2.The data is exored with FF.This sets all the zeroes in the data to ones and all the ones to zeroes\n3.Then the data containing the ones in place where the original data had zeroes is used to clear the port.Hence only those pins corresponding to the Zeroes in the data are cleared.\n","permalink":"https://murli-shenoy.com/posts/lpc1768-sending-a-byte-output-to-a-port/","summary":"\u003cp\u003eJust  a Simple code snippet that allows you to send a byte over a 8-bit wide parallel bus when using 32 bit devices such as those based on the ARM architecture.\u003c/p\u003e\n\u003cp\u003eWhile programming AVRs this usually would suffice to send a BYTE over a parallel 8-bit wide port.Here’s an avr-gcc example\u003c/p\u003e\n\u003cp\u003ePORTC = data;\u003c/p\u003e\n\u003cp\u003eBut with the a 32-bit microcontroller For example the LPC1768 from NXP.\u003c/p\u003e\n\u003cp\u003eEach port is 32 bits wide and in order to send  a byte over an 8-bit section of the 32 bit wide ports\u003c/p\u003e","title":"LPC1768 – Sending a Byte output to a port"},{"content":"Recently the indian rupee joined the elite league of currencies that have their own unique symbol. The symbol is a combination of the devanagri ‘ra’ and also symbolises the roman letter R. the two stokes signifies the tricolour and the progress of the nation. here’s how u can use it in your emails and word documents.\nGiven below are the steps to use the new Indian Rupee Symbol as a Font in your word applications:\n1. Download the attached font Rupee.ttf or Rupee_Foradian.ttf\n2. Copy the font and paste it in “Fonts” folder in Control Panel.\n3. Open any Microsoft Office application (For E.g., Microsoft Office Word). (See Figure 1.a)\n4. Select the font type as Rupee or Rupee Foradian.\n5. Click on ` (Grave accent) symbol. This key is just above “tab” button in your keyboard. (See figure 2)\n6. You can see the new Rupee symbol in your office application.\nFigure 1.a. Rupee Symbol in MS word\nFigure 1.b. Rupee Symbol in Gmail application\nFigure2. Grave Accent Symbol\nLimitations:\nThe “Rupee.ttf” font is necessary to view the currency symbol. So as long as the new symbol is not encoded in to Unicode font by default,\nwe cant use the symbol universally.\nThanks to Foradian Technologies for giving these fonts as a free download to public\n","permalink":"https://murli-shenoy.com/posts/steps-to-include-indian-rupee-symbol-font-in-ms-word-applications/","summary":"\u003cp\u003eRecently the indian rupee joined the elite league of currencies that have their own unique symbol. The symbol is a combination of the devanagri ‘ra’ and also symbolises the roman letter R. the two stokes signifies the tricolour and the progress of the nation. here’s how u can use it in your emails and word documents.\u003c/p\u003e\n\u003cp\u003eGiven below are the steps to use the new Indian Rupee Symbol as a Font in your word applications:\u003c/p\u003e","title":"Steps to include Indian Rupee Symbol Font in MS word applications"},{"content":"Making a printed circuit board (PCB).\nFirst cut the copper clad board to size required. Sand the surface of the board to remove the layer of copper oxide that is formed due to the reaction of the copper with the oxygen in the air. Once the copper surface is shiny and clean avoid touching the surface of the copper. Eaglecad or ORCad may be used to design the schematic and the pcb design . Take a mirror image of the pcb design while using the CAM processor to generate the Gerber files . The gerber files maybe viewed online at http://www.circuitpeople.com or the .eps file maybe viewed offline using the .eps viewer take a lazer printout of the pcb layout using. this printout will be the mirror image of the actual pcb layout . Since during the transfer process the mirror image of the actual image will be transferred. Now cutout the actual PCB layout on the transperency. this will be the toner transfer . Lightly wipe the toner layer of the toner transfer with a peice of cloth and the surface of the cleaned copper clad. This will ensure that there is no dust or grime between the toner surface and the copper. Place the transfer on top of the cleaned copper clad board. Secure the layout in place with the help of a peice of tape or some glue. Using a hot clothes iron heat the toner transfer so that the toner layer from the tranfer is transferred onto the copper.(set the iron to the highest temperature possible…usually the cotton settings) Iron the transperency gently. Don’t put too much pressure on the clothes iron else the toner will smudge. too little pressure and the toner wont be transferred at all. Once you think the toner is stuck to the copper turn off the iron. let it cool down to the ambient temperature. Peel off the transperency if you got it right then you will see that almost all the toner has been transferred to the copper surface. The toner layer will form the etch resist. Now the copper clad can be put into the etching tank. ferric chloride maybe used as the etchant. although muriatic acid maybe used too. Gently ‘move’ the copper clad board through the FeCl3 solution. Once all the unwanted copper has been removed clean the PCB under running water. Remove the layer of the toner with some sand paper or a solvent such as acetone. If the PCB is meant for surface mount components then the PCB might require drilling. After the drilling is over. tin the copper surface to protect and increase the conductivity of the copper tracks. References:\nhttp://www.riccibitti.com/pcb/pcb.htm\nhttp://www.qsl.net/vk5cu/\nhttp://www.fullnet.com/~tomg/gooteepc.htm\nhttp://www.youritronics.com/diy-printed-circuit-board-using-photo-etching-method/\nHow-To: Etch a single sided PCB\n","permalink":"https://murli-shenoy.com/posts/make-a-pcb-yourself/","summary":"\u003cp\u003e\u003cstrong\u003eMaking  a printed circuit board (PCB).\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eFirst cut the copper clad board to size required.\u003c/li\u003e\n\u003cli\u003eSand the surface of the board to remove the layer of copper oxide that is formed due to the reaction of the copper with the oxygen in the air.\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"images/040420102056.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/040420102056.jpg\" title=\"sanded pcb\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eOnce the copper surface is shiny and clean avoid touching the surface of the copper.\u003c/li\u003e\n\u003cli\u003eEaglecad or ORCad may be used to design the schematic and the pcb design .\u003c/li\u003e\n\u003cli\u003eTake a mirror image of the pcb design while using the CAM processor to generate the Gerber files .\u003c/li\u003e\n\u003cli\u003eThe gerber files maybe viewed online at \u003ca href=\"http://www.circuitpeople.com\"\u003ehttp://www.circuitpeople.com\u003c/a\u003e or the .eps file maybe viewed offline using the .eps viewer  take a lazer printout of the pcb layout using. this printout will be the mirror image of the actual pcb layout .\u003c/li\u003e\n\u003cli\u003eSince during the transfer process the mirror image of the actual image will be transferred.\u003c/li\u003e\n\u003cli\u003eNow cutout the actual PCB layout on the transperency. this will be the toner transfer\u003c/li\u003e\n\u003cli\u003e.\u003ca href=\"images/040420102057.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/040420102057.jpg\" title=\"pcb2\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eLightly wipe the toner layer of the toner transfer with a peice of cloth and the surface of the cleaned copper clad. This will ensure that there is no dust or grime between the toner surface and the copper.\u003c/li\u003e\n\u003cli\u003ePlace the transfer on top of the cleaned copper clad board.\u003c/li\u003e\n\u003cli\u003eSecure the layout in place with the help of a peice of tape or some glue.\u003c/li\u003e\n\u003cli\u003eUsing a hot clothes iron heat the toner transfer so that the toner layer from the tranfer is transferred onto the copper.(set the iron to the highest temperature possible…usually the cotton settings)\u003c/li\u003e\n\u003cli\u003eIron the transperency gently.\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"images/040420102058.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/040420102058.jpg\" title=\"pcb3\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eDon’t put too much pressure on the clothes iron else the toner will smudge. too little pressure and the toner wont be transferred at all.\u003c/li\u003e\n\u003cli\u003eOnce you think the toner is stuck to the copper turn off the iron. let it cool down to the ambient temperature.\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"images/050420102059.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/050420102059.jpg\" title=\"pcb4\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003ePeel off the transperency if you got it right then you will see that almost all the toner has been transferred to the copper surface.\u003c/li\u003e\n\u003cli\u003eThe toner layer will form the etch resist.\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"pcb-making1.doc\"\u003e\u003c/a\u003e\u003ca href=\"images/0504201020601.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/0504201020601.jpg\" title=\"050420102060\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eNow the copper clad can be put into the etching tank. ferric chloride maybe used as the etchant. although muriatic acid maybe used too.\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"images/050420102062.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/050420102062.jpg\" title=\"050420102062\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eGently ‘move’ the copper clad board through the FeCl3 solution.\u003c/li\u003e\n\u003cli\u003eOnce all the unwanted copper has been removed clean the PCB under running water.\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"images/050420102064.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/050420102064.jpg\" title=\"050420102064\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eRemove the layer of the toner with some sand paper or a solvent such as acetone.\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"images/050420102065.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/posts/make-a-pcb-yourself/images/050420102065.jpg\" title=\"050420102065\"\u003e\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eIf the PCB is meant for surface mount components then the PCB might require drilling.\u003c/li\u003e\n\u003cli\u003eAfter the drilling is over. tin the copper surface to protect and increase the conductivity of the copper tracks.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eReferences:\u003c/p\u003e","title":"make a PCB yourself"},{"content":" ","permalink":"https://murli-shenoy.com/posts/made-a-big-muff-pi-check-it-out-my-guitarist-buddies-are-checking-out-the-stuff/","summary":"\u003ciframe class=\"youtube-player\" width=\"640\" height=\"360\" src=\"https://www.youtube.com/embed/DJILTQNpt8w?version=3\u0026amp;rel=1\u0026amp;showsearch=0\u0026amp;showinfo=1\u0026amp;iv_load_policy=1\u0026amp;fs=1\u0026amp;hl=en\u0026amp;autohide=2\u0026amp;wmode=transparent\" allowfullscreen=\"true\" style=\"border:0;\" sandbox=\"allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox\"\u003e\u003c/iframe\u003e","title":"Made a Big Muff Pi….check it out…..my guitarist buddies are checking out the stuff!"},{"content":"Display Software Engineer | Test Automation \u0026amp; Calibration Expert I’m a Senior Software Engineer specializing in Display Engineering. My expertise lies in test automation, optical calibration, and defect detection. At Apple, I’ve developed instrumentation and test systems for products like Vision Pro, Studio Display, MacBook Pro, and iPhone. Currently, I’m part of the Display Software team, where I’m working on Pro features for Apple Displays. My experience includes working with spectroradiometer-based testing platforms, Display drivers hardware, calibration algorithms, and reliability stress testers that ensure display quality for millions of users. My work spans the entire software/Hardware stack, from PCB design and firmware to test software and data analysis to enable manufacturing displays at scale.\nContact \u0026amp; Links Email: shenoy.muralidhar.m@gmail.com GitHub: github.com/hmms Blog: murli-shenoy.com Location: San Francisco, CA Technical Expertise Display test software development (µOLED, OLED, LCD) Optical calibration \u0026amp; defect detection algorithms (Objective-C, MATLAB) Color science, color spaces, image processing Test station development (Python, Objective-C) Instrument qualification processes PCB schematic \u0026amp; layout (Altium) Firmware development (C/C++ for ARM, AVR microcontrollers) Vendor management \u0026amp; factory support Featured Projects In-Field Display Calibration — Apple Studio Display \u0026amp; M4 MacBook Pro Developed first-party display calibration feature for professional workflows (film production, photography). Collaborated across display hardware, firmware, and panel teams. View Apple Support Guide →\nVision Pro Display Quality Tester End-to-end development of spectroradiometer-based tester quantifying luminance, color, and uniformity at factory OQC. Defined ERS requirements, implemented test sequences, developed scalable algorithms.\niPhone LCD Yellow Mura Characterization Built characterization tester for iPhone XR/11 to help internal teams identify and analyze visible display blemishes.\niPhone \u0026amp; Apple Watch Reliability Stress Tester Designed low-cost, retrofittable, modular reliability testers for electromigration and corrosion stress testing. Covered iPhone models 2018–2023 and Apple Watch Series 5–8. Led vendor engineering teams and streamlined deployment processes.\nElectrochromic Glass Controller — View Inc Developed hardware specifications, firmware algorithms, and PCBA test/calibration systems for smart glass that tints on demand. Prototyped energy-saving features using Li-Ion supercapacitor storage.\nBluetooth Medical Device — Diabeto Lead hardware engineer for consumer Bluetooth glucose meter. Prototype enabled critical funding; company acquired by Livongo (now Teladoc).\nTimeline 2017–Present Apple Inc. — Sr. Software Engineer, Instrumentation \u0026amp; Test Development | Cupertino, CA\nIn-field display calibration for Studio Display and MacBook Pro Near-eye µOLED display characterization tester for Vision Pro factory OQC iPhone LCD Yellow Mura characterization tester (iPhone XR, iPhone 11) Lead for iPhone reliability tester development (2018–2021 models) Managed vendor relationships, EE/ME engineers, and factory deployments 2014–2017 View Inc. — Electrical Engineer | Milpitas, CA\nR\u0026amp;D for electrochromic window control electronics Modeled electrochromic device behavior Developed automated functional test, verification, and calibration procedures Led hardware reliability testing Prototyped new device concepts 2012 Diabeto (Farasbee Labs) — Hardware Lead | Mumbai, India\nLed Bluetooth medical device hardware development Developed prototypes optimized for production Collaborated with industrial design and UX teams 2010–2012 Automata Systems — Embedded Systems Developer | Mumbai, India\nPCB design for industrial motion control Developed scalable firmware for ARM and AVR microcontrollers Created low-cost motor control platform Education M.S. Electrical Engineering — San Jose State University (2014) B.E. Instrumentation — Mumbai University (2011) Awards \u0026amp; Recognition Titan Business Award (Platinum) — Information Technology, NextGen Technology Titan Innovation Award (Platinum) — Innovation in Technology, Software Technology Noble Award (Platinum) — Virtual \u0026amp; Augmented Reality, Outstanding Achievement in Product Development 1st Place, Integrate Hackathon 2015 — “Intelligent Energy Saving Smart-Plug” (Intel Edison IoT) Publications “Display Technologies Revolutionizing Visual Interfaces Through Innovation” “The Critical Role of Test and Calibration in Modern Display Engineering” “Emerging Display Technologies in Contemporary Art: A Technical Analysis” “Testing and Calibration Methodologies for Automotive Displays: A Comprehensive Analysis” Professional Memberships Senior Member, IEEE Fellow of IAEME, IETE Full Member, Sigma XI, Hackathon Raptors Judge, Globee® Awards for Leadership \u0026amp; Cybersecurity Hobby Projects Capacitive Touch LED Toy — Low-power microcontroller project Fast Charging Technology Explained — Technical deep-dive LED Chandelier — Diwali light project Bluetooth RGB LED Controller — Featured on Dangerous Prototypes ","permalink":"https://murli-shenoy.com/pages/about-2/","summary":"\u003ch2 id=\"display-software-engineer--test-automation--calibration-expert\"\u003eDisplay Software Engineer | Test Automation \u0026amp; Calibration Expert\u003c/h2\u003e\n\u003cp\u003e\u003ca href=\"images/murli_profilepic.jpg\"\u003e\u003cimg loading=\"lazy\" src=\"/pages/about-2/images/murli_profilepic.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003eI’m a Senior Software Engineer specializing in Display Engineering. My expertise lies in test automation, optical calibration, and defect detection. At Apple, I’ve developed instrumentation and test systems for products like Vision Pro, Studio Display, MacBook Pro, and iPhone. Currently, I’m part of the Display Software team, where I’m working on Pro features for Apple Displays. My experience includes working with spectroradiometer-based testing platforms, Display drivers hardware, calibration algorithms, and reliability stress testers that ensure display quality for millions of users. My work spans the entire software/Hardware stack, from PCB design and firmware to test software and data analysis to enable manufacturing displays at scale.\u003c/p\u003e","title":"Muralidhar M Shenoy"},{"content":"Happy diwali to all!!!\nLast week i was alone at home since my parents had gone out to attend a marriage in mangalore.I was alone at home for about 10 days and had no college since there was our college ‘techfest’.i dont like attending ‘techfests’ on a shoestring budget,like the one in our college!!.there only a few things which fit into my definition of tech there!\nSo I was alone \u0026amp; bored and to get rid of my boredom and loneliness i wanted to do some fun project.i had a few hundred bucks with me,and i had an old luminaire (called jhoomer in hindi)-it had those bayonet mounted so called ‘zero watt’ incandescent bulbs. I consider incandescents a thing of the past as they are very inefficient and are energy guzzlers-they waste a lot of energy as heat.Infact they generate much more heat than they produce light!!!So i thought that replacing the incandescents with power LEDs which consume lower power and produce much more light.Also the light is much more soothing to the eye.\nI went to the electronics heaven of mumbai-lamington road.with my friend Vijay to get some 1 watt LEDs.In my previous posts i have written about these LEDs and how to drive them.I got six 1 watt LEDs since my luminiare had six ‘arm’s.i could simply hook these leds to a wall wart of about 12 volts and a current rating of about 600 ma.hook it up in two parallel rows of three series LEDs .each LED requires a voltage drop of about 3.4v and a current of 300ma.that totals to about 10.2 volts and 600ma total power required. simple eh?? but that’s not the case these led are much more complicated devices as mentioned in the past posts.They require a constant regulated supply for stable and reliable operation. With the correct type of supply a long life can be expected of these LEDs.Usually these LEDs are rated for about 10,000 to 100,000 hours of operation.Thats miles ahead of the current fluorescent and incandescent technologies.\nSo i had to make the power supply for these LEDs so as to ensure reliable operation.I had a few LM3404 samples i had received from National semiconductor lying around.Its a buck converter based constant current source LED driver.It has an internal MOSFET capable to switch up an amp of current. requires very few external components for operation.Hence is ideal for my project.Also since it’s switching based device it has very high efficiency.So my objective of going green is fulfilled too.The rest of the components used have been salvaged from old electronics-old PC SMPS,old nokia charger,cordless phones,TV video games,FM radio,DVD writer etc.I firmly beleive in recycling!!.\nNow i checked out the datasheet of the LM3404,there were a lot of formulae and stuff on how to calculate the values of the various components used in the circuit.I found it difficult to get the accurate values of these components .I was also not too sure about the values being accurate. so i tried out the webench tools from National Semiconductor.These are great free tools from national which help in designing circuits based on their ICs.registration is required to use these tools which is also free. now on the webench designer page for LM3404 there were fields for the forward voltage of the LEDs,forward current,etc.I had no exact values for my LEDs since the guy whom i brought it from just referred to the as chinese made 1w led.So i assumed that it would be having a forward voltage of 3.4v and a current of 350ma.To confirm my assumption i had to check these specs with my multimeter.the volatge across the LED was 3.18v @133ma and 3.32v @210ma.I used a constant current supply mentioned in my provious post on power LEDs to check the voltage across the led.These values also help in determining the Rdyanmic-the dynamic resistance of the LED also known as ESR(equivalent series resistance).usually it is 1-2 ohms for power LEDs. In my case it was 1.81 ohms.The ESR can be calculated by measuring the increase in forward voltage drop dividedby the increase in current. For example, if the forward voltage drop increases by from 3.5V to 3.55V (a 50mV increase) when the forward current goes from 10mA to 20mA (a 10mA increase), the ESR will be 50 mV/10mA=5 ohms.I’ll be using a 12volt-1amp Wall wart from a deceased cordless phone as power souce for the LED driver cicuit.Take a printout of the circuit designed by the webench designer,as you’ll be needing it for further reference.here’s mine. there are 2 strings of three LEDs in parallel at the output block.\nlet’s start building the circuit now.The LM3404 chip was in a PSOP-8(power small outline package-8 pins)package.The SMD package is very tiny and i had to refer some sites to learn how to solder SMDs at home.The whole chip is just a couple of mm in width and in length!!I had to handle these using tweezers.First I placed the chip on a bare pcb coated with the ink from a permenent marker.\nthen i drew a few lines between the leads of the chip using the pointed end of one leg of the tweezer as shown.this exposes the copper of the pcb.Here the chip acts as the stencil.the chip can be held in place using an end of a toothpick.\nextend the lines further and widen these lines if possible,to allow for use of thru hole components.now prepare the etching solution.I prefer ferric chloride. hold the pcb by means of a ‘holder’ i hav made one out of thick laminated copper wire.dip it into the etching soln.keep stirring continously.sometimes heating may also be required for speeding up the process.after the etching is done and all the bare copper is removed, remove the marker ink using acetone(sold as nail paint remover). your pcb is ready. check for any short circuits between the various parts of the pcb usin multimeter.i kept a small patch of copper shorted with the ground under the pcb to act as a heatsink since this chip has a powerpad at the bottom which is grounded.this power pad help dissipate heat as well as increase the sink/source capability of the chip.\nfirst of all hold the chip in place using a tootpick on the prepared PCB. solder just the pin no.1.this helps to keep the chip in place.now now solder the pin no.8. now the rest of the pin are soldered by placing a blob of solder on all the four pins on one side .then the blob maybe sucked out using desoldering braid which leaves only the required quantity of solder on the pad.the process is repeated on the other side as well. check for the continuity between the pads and the pins by a multimeter,once confirmed.proceed to soldering the other components.\nslightly bend the legs of the thru hole components then tin them.then solder these components over the\nnow try applying a thin layer of solder over the pcb.this helps in increasing the current carrying capacity of the pcb as well as to prevent oxidation of the copper.solder the components on the pcb as shown.a thin sticky layer of slag was formed on the pcb while soldering.this can be easily removed by rubbing a peice of cotton soaked in acetone.\ni use this technique to ‘surface mount’ thru hole devices.this technique is great for prototyping.this method can also be used for ‘permanentizing’ the circuit. heres the completed circuit. before testing the circuit do remember to remove the slag as i can form a capacitor between the pins.this stray capacitance can damage the circuit and lead to malfunction and i learnt this the hard way.I had to sacrifice a IC to this stray capacitance :(.\nthe led driver circuit is ready now.\nNow these LEDs cary a huge amount of power for their size.They generate some heat so heat sinking is required to prevent any damage due to overheating.I got some small heatsinks that could fit in the bulbholders themselves so there’s no need to reengineer the LED mount.the LEDs were ‘stuck’ to the heatsinks by means of heats ink compound.a small container of this thermal compound would suffice and the cost just 10 bucks.i would suggest polishing the surface of the heatsink before applying the thermal paste.It is not necessary though.Just to be on the safer side i polished the surface of the heatsink with some sand paper.a very small amount of thermal paste is applied on the heatsink.so as to form a very thin layer. the LED is the placed on the heatsink and a small amount of force may be applied so as to place the LED firmly in place.this step is repated for all the leds.\ni managed to squeeze the LEDs fitted with the heatsink into the bayonet mountings of the incandescent bulb.this made my job of mounting the LEDs a bit easy.a lot of improvisation might be needed here.i also rewired the whole Luminaire. since the wire was old and was oxidised. i connected the each set of 3 LEDs in series. this gave me 2 strings of 3 series LEDs. i connected these two strings in parallel. i first tested the circuit with the 12v out from an computer SMPS.the yellow wire from the SMPS is the +12v while the black wire is the ground. the test was sucessfull so i proceeded to mounting the circuit.i attached a barrel plug connector to driver circuit so as to allow the connection of a standard wall wart supply. i used a 12v-1amp adapter that was used as a supply for a cordless phone. i mounted the circuit on the wallwart itself with some insulation tape.the supply for the adapter is given from the mains .after testing the circuit for another hour to check the stability i reassembled the luminaire and hung it back up on the ceiling.\nNote:i was unable to upload the photos of soldering the through hole components on the SMD pcb due to some technical glitches.sorry for the incompleteness.will upload the pics as soon as possible.Also thanks to mandar for staying up late until the wee hours of morning and for that can of redbull which helped me stay up that late 😉\n","permalink":"https://murli-shenoy.com/posts/diwali-project-led-luminaire/","summary":"\u003cp\u003eHappy diwali to all!!!\u003c/p\u003e\n\u003cp\u003eLast week i was alone at home since my parents had gone out to attend a marriage in mangalore.I was alone at home for about 10 days and had no college since there was our college ‘techfest’.i dont like attending ‘techfests’ on a shoestring budget,like the one in our college!!.there only a few things which fit into my definition of tech there!\u003c/p\u003e\n\u003cp\u003eSo I was alone \u0026amp; bored and to get rid of my boredom and loneliness i wanted to do some fun project.i had a few hundred bucks with me,and i had an old luminaire (called \u003cem\u003ejhoomer\u003c/em\u003e in hindi)-it had those bayonet mounted so called ‘zero watt’ incandescent bulbs. I consider incandescents a thing of the past as they are very inefficient and are energy guzzlers-they waste a lot of energy as heat.Infact they generate much more heat than they produce light!!!So i thought that replacing the incandescents with power LEDs which consume lower power and produce much more light.Also the light is much more soothing to the eye.\u003c/p\u003e","title":"DIWALI PROJECT – LED luminaire"},{"content":"\nI was desperately in need of a good pair of in-ear earphones for a long time since my JVC FX-33 marshmallows went kaput a few months ago.So I got myself a new philips she-9500 from the tech haven of mumbai aka lamington road for about 750 INR a couple of days ago. I had done quite a bit of research before buying these earphones.Here’s the review.\nFirst of all i’m no hardcore audiophile,but the audio quality is a top priority to me and i can’t bear to hear the bassless music from the silly nokia earphones bundled with my nokia n78.I a huge linkin park fan and i can hear linkin park all day long!!. The philips earphones are very good VFM earphones. The transperent blister package it came in contains the following.\nthe earphones themselves(length-60cm) a 60 cm long extender cable a carrying pouch a small earphones box a couple of extra pairs of rubber tips of different sizes(small,medium,large). For 750 bucks thats more than enough i think.I was contempalting maybe a creative or maybe a sony before finally settling on the philips one. There are various models in the 500-1000Rs. range from creative,sony and panasonic.But the best thing i found about these earphones during my pre-purcahse reasearch was that these earphones have great bass.This is very much evident from the bass vents present at the back of the earphones.I had also found many good comments on these earphones on various forums.Although there were even comments that suggested that these earphones lacked the ‘meatiness’ in the bass range.\nNow about the construction of these earphones.The earphones are built solidly enough but can’t say the same about the cord though. The wire has a slight rubbery texture and is very thin a looks flimsy. Although the wire feels much stronger than it looks.The plugs are all 24k gold plated. Even the extender cable has the connectors gold plated. My experience suggests that this gold plating tends to wear off with use.The rubber cups provided have a soft feel to them and are of good quality.The manage to have the right balance between providing good isolation and providing comfort.I can wear these earbuds for hours without feeling any discomfort,or any itchy feeling,the earbuds are so comfortable that i tend to forget that i have even worn them.This was not my case with the JVC marshmallows. The memory foam insulation provided with those earbuds was good at providin isolation,but comfort was not one of its strong points.I have read many comments on various forums such head-fi.org,iaudiophile,etc that the assymetric cable length of these earphones as being ‘clumsy’. I consider this feature as a plus point. this makes wearing these earphones even more comfortable.\nNow,for the audio quality department.these earphones have a very decent audio quality. Altough i had expected more. But i guess that the comfort does come at a price.The isolation is not what i would get from my marshmallows.I think the isolation provided by the jvc was unbeatable.The complete sealing of this earphones is compromised due to the bass vents present at the rear i think.The bass is more pronounced due to this.Hence it’s like a necessary evil!!The bass and treble felt rich. The midrange was so-so. One major drawback of these earbuds is that the sound crackles when the eq settings are fiddled with,especially the bass booster setting. I had to change the default nokia bass booster settings reducing the bass range pointer to a level slightly above default.But one thing that i noticed was that the sound at the default settings itself was good enough and no bass booster setting were needed,even a bassophile like me could do away with the bass booster settings.This was not the case with the jvc marshmallows. There was no severe distortion even when all the eq settings were kept very high.So go for the SHE9500 earphones only if are willing to do away with the eq settings altogether.This was one major dissapointment i had with these earbuds.I’m very much fond of fiddling with the eq settings and i always keep the bass at a very high level.\nto sum it all up\nPROS\ngreat vfm,cant beat the performance at this price point,even the creative ep630 costs 800 bucks and has much inferior bass(very boomy and hollow) altough it can handle high eq settings. The asymmetric cable length. Extremly comfortable. Comes with great carrying box,pouch. Ideal for use with mobile phones,since the cable is of short length without the extender,can be directly connected to the handsfree port of your mobile.can be used with mp3 player with the extender cable.(a nifty feature indeed). Good bass for the price. CONS\nThe cord is very thin,could have been of much better quality(one thing i liked very much about my jvc FX-33 was that the cable was very solidly built and was very thick and storng,certainly not a strong point of the SHE9500). The sound quality could have been much better,the midrange is a weak point.But the price is a much stronger point here which influences me. The chrome tends to attract a lot of attention. but thats pro right?But i think that the earphones should blend in which this earphones certainly dont.certainly could have been better without the chrome! Isolation not very good.That might sometimes be a lifesaver,while walking on the streets listening to music it is necessary that you hear outside sounds and thus might prevent accidents.\nThese earphones are ideal if you are on a shoestring budget and are looking for a good pair of earbuds. for the price the sound and comfort is great.The cable with the extender is great for use with mobile phones having the remote for music player. If you have a flexible budget go for the sennheiser cx180,or maybe philips SHE9501,or the sonys they have much better sound quality but the price too is greater\n","permalink":"https://murli-shenoy.com/posts/philips-she-9500-reviews/","summary":"\u003cp\u003e\u003ca href=\"images/160920091145.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"images/160920091135.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"images/160920091132.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003eI was desperately in need of a good pair of in-ear earphones for a long time since my JVC FX-33 marshmallows went kaput a few months ago.So I got myself a new philips she-9500 from the tech haven of mumbai aka lamington road for about 750 INR a couple of days ago. I had done quite a bit of research before buying these earphones.Here’s the review.\u003c/p\u003e\n\u003cp\u003eFirst of all i’m no hardcore audiophile,but the audio quality is a top priority to me and i can’t bear to hear the bassless music from the silly nokia earphones bundled with my nokia n78.I a huge linkin park fan and i can hear linkin park all day long!!. The philips earphones are very good VFM earphones. The transperent blister package it came in contains the following.\u003c/p\u003e","title":"philips she-9500 reviews"},{"content":"\nIn my earlier post i had made a gadget charger which could charge your mobile phone,ipod,or other gadgets.It was based on a rather simple chip -the humble 7805. Now lets move a step further and make a more efficient emergency charger. this charger is based on the lt1302 from linear technology. I had got as samples from linear.com samples service two lt1302 ics .the datasheet provided very promising numbers efficiency reaching nearly 87%!! wow!!!!that’s great.That means more charge gets into your gadget.\nThe IC is a boost converter IC .As the name suggests it boosts the input voltage.It forms a very simple switching mode power supply. From the datasheet i found that it can operate down to voltages as low as 2v.That means we will can use two 1.5v alkaline or 1.2v ni-mh rechargeablesas the power source(as the cells discharge their voltage falls below the rated volatge,Ni-mhs usually discharge down to 1.0 v per cell before they need a recharge).Now what exactly is a boost converter??? . A boost converter is a form of a smps.It’s basic circuit is as follows.\nBasic boost converter\nsource:wikipedia\nTo understand better try wikipedia.what it basically does is it employs an inductor to store energy from supply as the switch switches on and off rapidly.This switching on-off happens at a very high frequency upto 310 khz in this case.The switch in the SMPS of your PC is usually a MOSFET or an IGBT.These devices can handle a huge amount of power i.e. upto 50A constant current and 200A transients!!.These devices have very low on state resistances usually 0.015-0.018Ω hence the power losses across these devices are less.A simple BC547 NPN transistor can handle upto a few hundred mA hence in comparison these devices have very high power rating.These switches are turned on-off by means of an oscillator connected to a comparator which takes feedback and adjusts the frequency accordingly.Thus modifying the pulse width depending upon the power requirement. This is called pulse width modulation.\nEnough basics.Back to our project now.All the switches,pwm comparators, etc are built right into the lt1302. a few external components are required such as a schotthy diode(warning do not use 1N400 series diodes they are designed to work at low frequencies and hence will not work.),power inductor(I salvaged mine from an old printer), a few caps and resistors,Oh and a perf board or pcb to mount them all.\nHere’s the schematic.\nschematic for gadget charger using Lt1302.\nThe input capacitors are present for the noise suppresion. now when the circuit is given the supply the switch is off which charges the inductor through the sw pin now the switch turns on then the energey stored in the inductor along with the energy from the supply are fed to the output. the 220uf o/p smoothing capacitor is present for smoothing the output. the capacitor iaverages the output. a gives a good consistent output. The inductor should usually have very low dc resistance to reduce copper losses. The inductor should have a rated current of at least 2A. checkout the ones from coiltronics and coil craft.The output maybe connected to a usb female jack to charge your usb device such as a mp3 player or in my case it’s the nokia 2.5mm male charging connector.\nThis charger has higher efficiency also the output of this circuit is 600ma max. so this can charge your device pretty quickly. my nokia n78 charges from near empty to full in about 2 hrs.compare that to a standard wall charger which takes 1.5 hrs for a full charge.Thats pretty good for a portable charger i think. I use 2100mAh Ni-Mh rechargeables as the power source.they last me for more than one full charge..the batteries and the inductors do get very hot when in use.you can leave the batteries in the circuit itsel when not in use since the quienscent or “housekeeping” currrent of this circuit is about a few hundred microAmps but this will drain the batteries eventually ,or better still you may include an on/off switch with the battery holder .i wrapped the whole circuit in insulation tape to protect it and increase the ruggedness.i did not find the inductor the correct value so i tied two inductors in parallel to get the desired value.Inductors in parallel are very much like reistance in parallel they follow similiar formula for calculation.\n","permalink":"https://murli-shenoy.com/posts/high-efficiency-portable-gadget-charger/","summary":"\u003cp\u003e\u003ca href=\"images/11072009481.jpg\"\u003e\u003c/a\u003e\u003ca href=\"images/11072009478.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"images/Boost_circuit.png\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003eIn my earlier post i had made a gadget charger which could charge your mobile phone,ipod,or other gadgets.It was based on a rather simple chip -the humble 7805. Now lets move a step further and make a more efficient emergency charger. this charger is based on the lt1302 from linear technology. I had got as samples from linear.com samples service two lt1302 ics .the datasheet provided very promising numbers efficiency reaching nearly 87%!! wow!!!!that’s great.That means more charge gets into your gadget.\u003c/p\u003e","title":"High efficiency portable gadget charger"},{"content":"\nI have a nokia n78.I often use the gps onboard to find my way through the urban jungle of mumbai.The gps is surely a very useful tool for navigation but it tends to suck the battery juice pretty quickly. My phone can give only about 3-4 hrs of continous gps use on a full recharge.I’m a urban explorer kind of a guy so i like getting lost and found in the concrete jungle but that sometimes takes a lot of time.so much time that my battery runs out before my adventure is over!!. and so i decided to make myself a portable mobile charger.\nLets get to the basics of how the Li-ion/Li-po battery inside the mobile phone/gadget is charged. The wall adapter charger supplied with you mobile/gadget is basically a 5-7 volt regulated voltage supply.It may also be an smps providing a constant volatage.this volatge is not given directly to the battery but fed through a charge controller. the charge controller basically is another regulator that charges the battery at the precise voltage it requires.\nhttp://www.batteryuniversity.com/partone-12.htm for more on Li-ion batteries.\nThis charge regulator is present in the phone itself. The charger we are going to design is going to supply regulated 5 volts to this charge regulator which will then charge your battery.\nThe simplest way would be to use a 7805 with a 9v battery. As shown in the schematic below.\ncharger using 7805\nThis is obviously a simple circuit and also the components are cheap. Well i found out that the the 7805 is a very inefficient device .It dissipates a lot of heat.I recon it might have an efficiency of about 60% or so and also the amount of charge that gets into your mobile is also very less.Also the capacity of an average 9 v battery is around 600mAh.To charge my mobile i connected the 2.5 mm charging connector i salvaged from an broken ca44 cable.The smaller end is the 2.5 mm male plug connector.The outer terminal of the barrel jack is the negative. while the inner terminal is the positive. this charger really works but the amount of charge that this circuit will provide is relatively small as compared to a boost regulator based charging circuit which will be my next post.\n","permalink":"https://murli-shenoy.com/posts/diy-emergency-gadget-charger/","summary":"\u003cp\u003e\u003ca href=\"images/ca-44.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"images/ca-441.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"http://www.uk-mobilestore.co.uk/images/ca-44.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"images/7805charger.png\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"images/partone-12.gif\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003eI have a nokia n78.I often use the gps onboard to find my way through the urban jungle of mumbai.The gps is surely a very useful tool for navigation but it tends to suck the battery juice pretty quickly. My phone can give only about 3-4 hrs of continous gps use on a full recharge.I’m a urban explorer kind of a guy so i like getting lost and found in the concrete jungle but that sometimes takes a lot of time.so much time that my battery runs out before my adventure is over!!. and so i decided to make myself a portable mobile charger.\u003c/p\u003e","title":"diy emergency gadget charger"},{"content":"\nThese Days power leds are available very cheap.I had seen a lot of stuff on the net about the “1 watt led” and i fell instantly in love with these beauties!!These babies have a very high lumen per watt output as compared to either incandescent or the flourescent technologies.For the layman this means very high efficiency-you get more bang for your buck.But driving these things may be a bit difficult .\nI did some reasearch and found that the humble resistor we all connect to the leds while driving the usual 5mm leds does not work very efficiently for the power leds and hence complicated driver circuits are required.to understand how the driver works we need to first understand the basic principle on which the leds work. LEDs are current driven devices i.e one can increase the brightness of the LEDs by increasing the current through them. Sounds simple right!!.But it is much complicated than that the LEDs require a particular forward voltage known asforward breakover voltage. This is the voltage required to ‘turn on’ the LED.For white LEDs this is usually 3.2-3.4 v. Red and green LEDs usually have a much lower forward breakover voltage.Once the forward breakover is reached the leds literally act as a short circuit hence the current limiting resistor.These resistors cannot be used because of aforementioned reasons.Hence we use a constant current source. SMPS(switched mode power supply)s are usually used as a source for power LEDs. They usually switch on and off at a very high frequency.And that too at a very high efficiency of about 85-95%. The only drawback of such a power supply is the prohibitive cost,especially when the supply current is in a couple of amperes\nAll said and done i decided to make my own 1watt led lamp. I’m using a 1w LED with nothing but a 6N printed on it as you can see(i think this might be some cheap chinese made replica of the philips lumileds luxeon I). An lm317 adjustable volatage regulator and a 3.9 ohm 1 watt resistor. A heatsink i salvaged from an old TV receiver box.I’m using a nokia mobile charger model ACP-12E has a rated output of 5.7v@800ma.But my multiimeter gave me an output of 7v!! maybe because it was the open circuit voltage.\nI chose the lm317 because it has a constant current mode (see the application notes) and also its damn cheap.The lm317 can handle currents upto 1.5A .I suggest attaching a heatsink to the Lm317 as well as theLED. Altough the LM317 has thermal protection buit in the led may heat up and an overheated LED is as good as dead .The LM317 regulator gives out a constant voltage of 1,25 volts between ADJ and Vout, so by adding a resistor between these two outputs, you’ll get a constant current.to find the resistance value use ohms law V=IR.Here the V=1.25v and required I is .350A hence we get R as 3.5714ohms. the nearest standard value is 3.3ohm .But we will use the 3.9ohm as a safe measure. The constant current source has a voltage drop of 3 v. And since the voltage drop across the LED is 3.2 v we would require around 6v as vcc.Avoid using higher volatge power supplies than required since excess voltage is wasted as heat. I suggest using a supply of 6 to 9 volt.Also the wattage of the resistors may be high enough to handle the heat generated.\nThe finished product is shown below.This might not be the most efficient way to power these 1w LEDs but it’s the simplest and the most cost effective. The efficiency may be increased by using the right supply voltage to reduce the power wastage.\n","permalink":"https://murli-shenoy.com/posts/1-watt-high-efficiency-power-led-lamp/","summary":"\u003cp\u003e\u003ca href=\"images/05072009431.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003ca href=\"images/05072009428.jpg\"\u003e\u003c/a\u003e\u003ca href=\"images/05072009425.jpg\"\u003e\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003eThese Days power leds are available very cheap.I had seen a lot of stuff on the net about the “1 watt led” and i fell instantly in love with these beauties!!These babies have a very high lumen per watt output as compared to either incandescent or the flourescent technologies.For the layman this means very high efficiency-you get more bang for your buck.But driving these things may be a bit difficult .\u003c/p\u003e","title":"1 watt High Efficiency Power LED lamp"},{"content":"This is my first post on this blog.In this blog i plan to record my jouney in the fascinating world of elctronics and microcontrollers.Electronics is my passion and whenever i find spare time i indulge in either making electronics or breaking them. So far i have made as well as opened up a lot of electronics stuffs. From these i have gained a lot of knowledge.I would be recording all the knowledge i learn on electronics on this blog.\n","permalink":"https://murli-shenoy.com/posts/my-first-post/","summary":"\u003cp\u003eThis is my first post on this blog.In this blog i plan to record my jouney in the fascinating world of elctronics and microcontrollers.Electronics is my passion and whenever i find spare time i indulge in either making electronics or breaking them. So far i have made as well as opened up a lot of electronics stuffs. From these i have gained a lot of knowledge.I would be recording all the knowledge i learn on electronics on this blog.\u003c/p\u003e","title":"My first Post"}]