Month: January 2015

  • Tim Tears It Apart: Measurement Specialties Inc. 832M1 Accelerometer

    So, yesterday the outdoors turned into this. Not quite the snowpocalypse, but it was enough that a travel ban was in effect, and work was closed. What happens when we’re stuck in the house with gadgets? All right, I’d like to tell you that’s the reason, but this actually got broken open accidentally at my…

  • Tim Tears It Apart: Koolpad Qi Wireless Charger (Also: how to silence it without soldering)

    My wife goes to bed long before me, so when I go to bed, it behooves me to do so without significant light or racket. After countless nights of fiddling with a 3-sided micro-USB cable in the dark, I bought this neat little USB phone charger. It’s not the cheapest, nor the priciest, but was…

  • Tim Tears It Apart: Cheap Solar Pump

    So, I picked up a pair of these cheapo solar pump on fleabay for about 6 or 8 bucks a pop, to filter water for the fish in my old-lady-swallowed-a-fly lotus pot. They actually work pretty well, apart from one very occasionally getting stuck and needing a spin by hand to get going. But it’s…

  • Notes To Myself: Cheap Feedlines for Cheap Boards

    Goal: Produce reasonable impedance-matched (usually 50-ohms) RF feedlines for hobby-grade radio PCBs. Rather than get a PhD in RF engineering for a one-off project, use an online calculator and some rules of thumb to get a “good enough” first prototype. Problem: Most RF boards and stripline calculators assume or drive toward 4-layer boards. In hobby…

  • Debugging a shorted PCB the lazy way

    I recently assembled a set of prototype boards for a particular project at my day job, and ran a math- and memory-intensive test loop to test them out. Two of the boards ran the code fine, but one crashed consistently in a bizarre way that suggested corruption or otherwise unreliability of the RAM contents. Since…