Taking another crack at keyboard matrix scanning using the NRF52 PPI

Thanks, I'm looking forward to getting it working :)

I'm going to give the compiled JS a shot today hopefully! You're right that I wouldn't need the MCP chip to scan a 4x16 matrix, originally I wanted to do it that way for future expandability but the MDBT42Q has 32 GPIO pins, so that gives me the headroom to do a full size keyboard (6x22) with some extra GPIO to spare to do things like LED backlighting/dedicated buttons

So, set up watches on my columns, only scan when a watch gets triggered to stop us burning processor cycles at idle, and do the scanning in compiled JS or inline C to get a speed boost - that sounds like enough for me to get going with and see how far I get :)

Thanks for helping me out on this one, I might go quiet for a couple of days while I try this out but I'll post and update to let you know how its working out!