Bluetooth Low Energy Receiver for NES Controller

I've been thinking about revising the PCB design to use a Pi Pico W - I've had one on my desk for a while and have been thinking about ways to incorporate it into this design. I figure I can change the design of the PCB to incorporate the Pi Pico W and port the PIC routine to MicroPython code.

I haven't actually started any work on this, it was just an idea I had.

I was attempting to lift my ring buffer code from this project for a different, AVR-based project, only to find that the ring buffer did not work as intended in that application. I discovered a bug in the pop() function in which the head variable is not properly updated prior to retrieving information from the ring buffer i.e. head should be decremented prior to retrieving data. This has been fixed and the source file in the files section has been updated to reflect this change.

I also corrected some faulty timer interrupt logic, which resulted in the timeout always kicking in and resetting the 4021 bus. The tick count is now cleared every time a serial receive nterrupt fires.