Outguessing the machine

Category: gEEk

  • Exactly how much work is a half-assed job?

    If you tend to work smarter, not harder, you may at some point in your life have been accused of doing a half-assed job. But what, exactly, does that mean? How much work are you doing? How much energy are you putting into it?

  • Solved: Control Raspberry Pi media center (Kodi) with Roku TV’s remote over HDMI CEC

    TL;DR if you already figured out the documented stuff: Enable 2-way CEC (keypresses from TV remote to attached device) in the Roku secret menu: Quickly (within ~ 5 seconds) press Home 5 times, rewind, down, fast forward, down, rewind, and “Enable CEC Remote Control”. The options for viewing local content on my new Roku TV…

  • Spookifying Haunted Mirror build using Stable Diffusion

    For this Halloween, I built this haunted mirror display for the porch that turns any trick-or-treaters extra spooky. Using the voodoo power of AI, those who gaze into the mirror will be treated to a visage of their best Halloween self. See below for code and build tips if you’re interested in making your own!…

  • AllElectronics “Mystery Infrared Device” with LIRC

    NOTE: This device is no longer sold; rescuing this information before it disappears from various caches. Description of the device from AllElectronics: Our best guess is this is an infrared receiver/ transmitter for use with televisions or other remote-controlled equipment. Made for OnCommand™, it consists of a small black box, 2″ x 1.95″ x 0.6″…

  • CNC milling custom 40DP timing belt “gears”/pulleys

    Woo, it’s been a long time since I messed with pick & place stuff. Bad Tim. An irritation I have been having is making everything work using reliably sourceable, off-the-shelf parts (not lucky eBay/surplus finds). In particular I’ve found small “tin can” stepper motors are hard to source in small quantities repeatably, and once you…

  • 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…

  • 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;…

  • Buying Parts

  • 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.…

  • 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(…

  • 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…

  • 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…

  • 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.

  • 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…

  • 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…

  • 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…

  • 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…

  • 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…

  • 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…

  • 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,…