[Noisebridge-discuss] reprap update - now with steppin'

[Andy Isaacson]

The RepRap team had a soldering party on Sunday 11/16.  We built
 * 6 opto endstops - http://make.rrrf.org/oes-1.0
 * 3 stepper drivers - http://make.rrrf.org/smd-1.2
 * 1 DC motor driver - http://make.rrrf.org/dcmd-1.1
 * 1 temp sensor - http://make.rrrf.org/ts-1.0
 * 1 PWM driver - http://make.rrrf.org/pd-1.1

I made some mistakes when ordering parts, so for example the Stepper
Driver boards are missing their trim pots and their IDC cable headers.
I've ordered the missing parts; they'll be here on 11/24.

In the meantime, I hacked one of the SD boards using the wrong trim pot
(2k vs 10k, close enough for a hack) and reverse engineered the wiring
harness for one of the salvaged stepper motors and loaded the test
sketch onto a Boarduino.  The SD board worked as expected (although it
overheated easily, I think because the motor in question is very low
resistance compared to the ones the board is designed to work with, but
possibly due to the 2k trim pot I'm using.)

I also managed to fry a trace on the SD board by accidentally shorting a
live pin to ground. :{  (It was my oscilloscope ground clip that did it,
word of warning to you o-scope folks...)  Luckily it was *just* the
trace that blew, not an IC, and I was able to repair the board in rework
with a jumper wire.

FWIW, I've received donations of $100 towards the cost of the parts, and
I've covered the rest of the electronics myself so far.  Further
donations would be appreciated.  Expenses are listed on the wiki:
https://www.noisebridge.net/wiki/RepRap

-andy