Tuesday, September 5, 2017

Micropad A-Star Micro rebuild

Genovation Micropad rebuilt with Pololu A-Star Micro

This is the second Parallel Micropad 621 I have rebuilt to be USB instead of Parallel. I used a Pro Micro and jumper cables for the first conversion. This time I added a female socket header to one side of an A-Star Micro. The A-Star Micro has a different pinout than the Pro Micro. The entire left half of the board is i/o pins. I used pins 1-9 for the 9 connections to the matrix on the Micropad. The result is very clean, no jumper wires.

I cut down a larger header to 10 positions and soldered it to one side of the A-Star Micro. Only 9 pins are needed to control the Micropad. I also soldered some pieces of wire to make resetting the A-Star Micro easier. It has the same type of Arduino bootloader as the Pro Micro.

Installed on the Micropad's 9pin header. Some thick double stick tape will hold it in place.

All that is needed now is a USB cable and some cable management.

The pinout from Pololu. Pins 1 through 9 are used.

The JSON file I used on kbfirmware.com is here, as well as the compiled hex.

More information on the disassembly of the Micropad and the matrix can be seen in the original post.