New ToyBrain Board Design

Version one of the ToyBrain boards had a bunch of problems:

  • TX and RX were swapped on the serial line header
  • The ICSP header was backwards
  • There was no debug LED
  • The SMD resistor pads for the reset pull-up resistor were too small
  • The connection for the reset switch was a 0.1″ header rather than a proper footprint
  • There was a lot of wasted space

Despite all of that, I managed to eventually get them working, with a slowed-down version of the Arduino bootloader, adapters for the ICSP and serial headers, and much messing about.

The new board is smaller, measuring about 1.5″ by 1.28″, and adds a proper reset switch, a SMD LED for debugging, corrected resistor footprints, and a (in my opinion) slicker layout. I still didn’t add voltage regulation or mounting holes, but I may be able to get a little space for the holes by moving a few traces in the corners of the board.