• Fun with cheap TV-tuner dongles and Software Defined Radio (SDR)

    So, last week I joined the bandwagon of exploring software-defined radio (SDR) via one of those super-cheap Chinese TV tuner USB sticks. In a nutshell, the idea of SDR is that, rather than the traditional approach of building dedicated radio receiver hardware for each possible RF band and modulation type (here’s your AM radio, here’s…

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  • Notes to myself: Using EnergyMicro EFM32 with GCC open-source toolchain

    The EFMs can be used with many different toolchains after installing EnergyMicro’s “Simplicity Studio” package, which includes board/chip support packages and some code examples. EnergyMicro’s application note AN0023 has an overall good overview of setting up an Eclipse + GCC (CodeSourcery) toolchain. Nevertheless, in attempting to replicate this process on my Win7 system (work PC;…

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  • The IOC, Trademark Law and You

    Yes, it’s true! With the London Olympic Games and Paralympic Games Act 2006 (UK), and similar laws pushed through in other countries as a condition of hosting a certain large quadrennial event (US- Amateur Sports Act of 1978; Canada- Olympic and Paralympics Marks Act), any infringing use of IOC ‘properties’ (similar to, but stronger than,…

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  • Buying Parts

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  • Solved: Can’t connect to high (>10) Windows COM ports / cleaning out unused COM ports

    Problem: Windows, and many Windows apps that use serial (COM) ports, have various problems accessing “high” numbered COM ports. I cannot find an authoritative or quantatative definition of “high” (and it may depend on your app), but I have seen apps start failing after COM8, COM9, COM15… anything in the 20s is asking for trouble.…

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  • Solved: SL4A force close when calling recognizeSpeech

    Problem: SL4A crashes upon the first call to recognizeSpeech() : com.googlecode.android_scripting stopped unexpectedly (Force Close). The corresponding Android log via adb shell #logcat: D/AndroidRuntime( 2785): Shutting down VM W/dalvikvm( 2785): threadid=1: thread exiting with uncaught exception (group=0x4 0018560) I/ActivityManager( 1429): Starting: Intent { act=android.speech.action.RECOGNIZE _SPEECH } from pid 2785 E/AndroidRuntime( 2785): FATAL EXCEPTION: main E/AndroidRuntime(…

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  • Computer-controlled RGB LED Buckyball

    Everyone and his brother has built LED cubes before, and while they are unmitigatedly awesome, I wanted to try something a little different. As far as I can tell, nobody has made an LED buckyball before! And of course, the requirements for such a large, sparse shape are a little different. In a typical LED…

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  • Fixing an Acer AL2216W LCD Monitor (Delta DAC-19M010 power supply, bad caps)

    There are several dozen of this model of monitor at my work since last year or so; the other day I found one on top of the dead electronics plunder pile recycling bin, looking brand new. Googling the model # and terms such as “problems” or “repair” or “won’t turn on” revealed pages of discussion…

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  • Slam Stick: dissected!

    Woot! It sounds like a gadget I designed will be featured in next month’s EDN magazine (Prying Eyes column). This must be some kind of ironic career turning point: I landed a job by reverse-engineering other peoples’ stuff; now people reverse-engineer my stuff.

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  • UVLO, Comparators with hysteresis (now with 20% more equations!)

    The Mosquino board is intended to operate from very low-power sources, such as RF, vibration energy harvesting and small thermal gradients (e.g. body heat). Although the ATMega and the rest of the circuit can be put to sleep at < <1uA once they have reached legal operating voltage, many semiconductor circuits fail this test with…

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  • Not Dead

    Really! Just busy with some real-life stuff, namely wedding related and home renovations. I haven’t forgotten about this pick & place stuff! Lately I’ve been spending most of my project time on getting Mosquino toward an official 1.0 release. The rev2 boards just came in, so once all the parts are in I should have…

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  • How to use your own modem with Comcast

    Typical frog in a hot pot scenario; when I joined Comcast the modem lease was like $1.50 a month, and I didn’t even think about it. As of recently it’s now crept up to $7.00 a month, which kind of made me sit up in shock. How much do those things actually cost, anyway? Answer:…

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  • Motorized SMT tape-and-reel feeder for DIY pick & place

    Despite the impact of work, wedding planning and Super Metroid fan-hacks (not necessarily in that order ;-) on my freetime, my scheme to design a DIY-able open pick & place system is starting to come along. So far, there is a proper vacuum placement head, a rough idea of what the software architecture might look…

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  • Tape Sprocket Creator

    This is a free (open source) Python script for creating feeder sprockets for e.g. perforated tape or film advance. I wrote it for myself to generate SMD tape-and-reel feed sprockets, but it might also be useful for making replacement sprockets for 8/16/35mm film, microfilm and paper-tape systems whose original reader hardware no longer exists or…

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  • I P, U P, everybody (DHC)Ps…

    My page that tells you your IP address is up and running again, after a PHP configuration change by my web host knocked it out. Anyway, enjoy the glory of finding out your external IP address without getting socked by porn popups!

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  • Reversing an aquarium pump

    An aquarium air pump can be used as an inexpensive source of low vacuum with a small amount of tweaking. Supplies needed are: The air pump Screwdriver (usually) to open the air pump Hose barb (your favorite size) for vacuum inlet Drill Glue (e.g. RTV/caulk, epoxy, etc.) Of course, you could convert one by sealing…

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  • Pick n place head update

    This is a quick follow up to the pick & place head article, in which I actually build the darn thing :-) As in, not just fit-test the parts together and take a picture, but actually pick and place some stuff with it. I’ve been busy/lazy, so not too much to show in terms of…

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  • Cubeternet 2MP UVC webcam teardown

    For my pick and place project, I picked up a pair of too-good-to-be-true webcams: the Cubeternet no-name UVC webcam. For this project, there is a lot to like: 2MP resolution (claimed, at least), built-in LED ring, cross-platform UVC interface, hand-adjustable focus and a legitimate glass (no polycarbonate) lens…for $16! Alas, my review of this cam…

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  • Image segmentation for PnP optical placement

    Quick ‘n dirty (but working!) image segmenter for randomly-strewn part identification. About 1 page worth of scripting takes an image of objects on background, determines which part is the background, determines the outside contour of each object and numbers each as a separate object. Now that it’s known where to look for one specific object,…

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  • Pick ‘n Place Head

    This weekend I got some parts in and put together a preliminary placement head for my open-source pick ‘n place project. My requirements are that it be buildable with off-the-shelf parts (ideally same-source, to save on shipping) and no special equipment, allow +/-180 degree rotation while maintaining an undisturbed vacuum, and support interchanging of the…

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