DorkbotPDX people doing strange things with electricity

JTAG AdapterI bricked my long-running Seagate Dockstar a few weeks ago, but it was OK because I had already transferred its duties to a beefier GuruPlug. However, I hate having dead hardware lying around, especially when I can fix it.

My house has/had an old alarm system with keypads and sensors here & there. However, the control unit was old and decrepit and had no security system behind it, so I yanked it out and tossed it. (Still in the junk pile if anybody wants it -- it was high-zoot back in the day, with a phone dialer and everything!)

I've been meaning to do this for a couple of years now. Nixie-tube house numbers. But houses don't move (often), so you really only need one digit per tube. Plus, you need it BIG.

Here's my latest PCB design. It's a breadboard-mount DC/DC converter. I run many of my projects off a big 12V battery because 1) I have one; 2) it holds a lot of energy; 3) it can put out a huge amount of current if I ask it to (this can also be bad -- I've smoked several devices when they weren't hooked up quite right and the battery did its thing.)

Following a post on Hackaday, I dug out an old LCD display and wrote a little program to run it. In normal/active mode, according to my mediocre meter, the whole thing draws 90-100uA. When you put it in sleep mode, it draws nothing. (Edit: I measured with a 5K sense resistor...at 3V, it appears to draw about 3.25uA. Not very much at all!) I hope I can find one of those little SO-8 solar cells to try with this!

Here's the order page...I hope I got everybody's stuff right (or at least my errors weren't for really expensive parts!) http://www.dorkbotpdx.org/node/613?size=_original

Paul told me it was difficult, but not impossible, to make an AVR USB bootloader that fits in 512 256 words of Flash (coincidentally, the size of the smallest configurable boot block on most of the USB-enabled AVR chips). So of course I had to try. But along the way, I needed an AVR serial programmer (to burn the boot block) but I didn't have one. However, I did have the broken Teensy Paul gave me (which had a few spare GPIOs after the Avago Yow! project) and Ward has been showing off his Txtzyme interpreter, so...

So Paul brought some Teensies that didn't pass testing -- pins shorted, or not connected, or something doesn't work for some reason. His evil bargain: you can have one for free, but you have to do something cool with it within a year, and then take a picture of it. If you don't ...

Not as sweet as Paul's hack, but here's what I did today...

Low-grade vinyl insulation on ribbon cable is stretchy enough to be pulled back, then slide back over soldered pins.