The Gnarled Fist

Dev 2

Dana L. Coe -

Ok, got the graphics properly settled. ST7789 now has it's own file and headers.

Works fine. Now on to the buttons.

What the hell. They were working FINE just yesterday.

MPR121 cheap-ass board from TaoBao

So it was maddening, swapped wires, swapped breakout, swapped the microcontroller - nada. Just dumped all buttons at once or - nothing.

After some sleuthing, I found that:

  1. My cheap ass board probably does not have pull-up resistors. Added 1KΩ resistors between the I2C lines and VIN. Helped.
  2. Evidently that's not all you can do. You need to strobe the I2C lines to let them know there is no funny business and you are the boss.
That's a while back indeed

MKAY. I guess now I can get on with the grunt work of replacing the old input routines. No alphanumeric for now, just want basic input.