Adafruit Accessories Quad Level-Shifter and NeoPixel Ring

Today I'll be using a 74AHCT125N  quad level-shifter to use a 5V 24 neoPixel ring with my Arduino Nano Connect. It is on pin 4.

That part was pretty easy. Wiring followed the adafruit reference. The only problem was sending the programmable input/output (PIO) state machine commands from one of the cores. This would cause animations to stall while running CPU-heavy instructions. I could run it on core0 since it will just be handling BLE communications. I would like it to be able to run the lights in some preset animations. Ideally independently while taking some FIFO interrupts from the main core. PIOs are capable of looping small snippets. I've only used PIOs once before using a Pi Pico and micropython.

Time for a dive into some assembly language with pioasm. The pico c sdk datasheet has great info on this at page 33.

References:

https://datasheets.raspberrypi.com/pico/raspberry-pi-pico-c-sdk.pdf

https://raspberrypi.github.io/pico-sdk-doxygen/group__hardware__pio.html

https://learn.adafruit.com/neopixels-on-raspberry-pi/raspberry-pi-wiring

https://github.com/MrYsLab/NeoPixelConnect

https://forum.arduino.cc/t/programming-pio-with-pico/704290

https://stackoverflow.com/questions/795286/what-does-the-question-mark-character-mean-in-c