Nova SMT Blinky

Description

This board is used in Nova Labs Eagle CAD and Surface-mount soldering classes. It consists of an ATTiny, 35 LEDs arranged in a 5x7 matrix, (2) 74HC164 8-bit shift registers, P-CH and N-CH SOT-23 drivers. All I/O is brought out to an .1" header.

All hardware and software is available on github: https://github.com/cogwheelcircuitworks/NovaSMTBlinky

You might also find them for sale on Tindie:
https://www.tindie.com/products/bcoggs/nova-smt-blinky--hackable-5x7-dot-matrix-/

Details

PROJECT HISTORY

In August 2015, when I heard Hackaday was coming to the Nova Labs Makerspace (in Northern VA) where I was a member, I used it as an excuse to put together the surface-mount soldering class I had been planning. Of course, I was not satisfied with the board you can find by searching on 'smt practice' on EBay. In a fit of poor-time managment I said to myself "How hard could it be to design a board specifically for the class ?"

Some requirements for the board:

All surface-mount
Nothing super-challenging for the newbie - SOT-23's, 1206's, SOICs..
It should do something mildly entertaining
It should be programmable

What I ended up with was an ATTiny driving a 7x5 led dot matrix. This had just the right amount of parts to solder during a 2.5hour class, and students would be able to take it home and program it.

In a flurry, I rushed out a design through Ospark using their super-swift service (suggestion: add overnight option and call it ludicrous-swift service). I validated that it worked and sent an order 25 boards. My guy in Shenzhen said they would arrive in time.

Well, in fact, they did not arrive in time for the first class, so we had to build generic Shenzhen practice boards. Just as we were finishing up, the familiar yellow DHL pillow arrived with the boards wrapped up inside houdini-style. So the remaining 3 classes I taught that weekend were able to use the custom board.

Of course, there were a few f'ups which made it into this version of the board.. This turned out to be a good thing as I was then able to show the class the fine art of bodge wiring...