Saturday, September 17, 2016

Dual Controller, Dual Matrix

GNAP with Dual Pro Micro's

  • Reactive LED
  • Dual 16Mhz Pro Micros
  • Laser cut wood case
  • TMK firmware

The first Pro Micro is running TMK, the second is running an Arduino script controlling the LEDs. They are connected together through the hardware serial ports. The LED matrix is connected the LEDs in the same pattern as the keyboard matrix to the second Pro Micro. All of the code is in the git repo. The Pro Micro running TMK was flashed with the LUFA mass storage bootloader to make flashing easier. The other Pro Micro has the stock Arduino bootloader for automatic flashing from within the Arduino environment.
Video example of the different effects in the Arduino sketch. The scan direction allows for a max of 4 LEDs on at the same time. A single AtMega32U4 pin can handle 40mA. Resistors were chosen to draw about 10mA each.

The Pro Micro's are socketed. I used the pins from 1n4148 diodes. A dip socket was used to hold everything in place while soldering. A piece of kapton tape is between the pro micro and the socket. This is to keep the solder from flowing down the pin into the socket.
The case was designed using Swill's case builder. It was cut at Ponoko. A short pigtail made from a cut up USB cable is used for the external USB connection.
 The next PCB version will have a mini USB connector soldered to the PCB.