For some weeks ago I decided to scrap the solution we had for the PS/2 and implement a new one. I did NOT make this decision on a whim, I found issues in how to handle the interrupts that I could not fix without re-designing large parts of the board.
Instead I went on a journey to implement microLind bus communication and interrupt handling on a atmega88. This had the following effects:
- IC count from 11 to 1
- 64 bytes FIFO buffers for both keyboard and mouse.
- Room on the board to add a battery and 32kHz crystal for a RTC in the atmega.
- Interrupts don’t release until the buffer is empty.
And all the new components are thru hole mounted, so I have at least not divided from that philosophy.
So the past weekend my son soldered the first prototype board so we could start testing everything. Even the power draw during sleep so we can estimate the life span for it.
