This code creates a UART TX on 8 sequential pins of the Raspberry Pi Pico. The main use case being MIDI splitter devices
The second 16 port implementation should work for any number of pins, but just acts as a pure copy to those pins instead of having individual control over every pin of every byte. Hence while less flexible, the controlling software is simpler (just send a uart byte and it's copied to every pin).
Only tested in the simulator so far. https://wokwi.com/projects/344345628967436882
Used https://wokwi.com/tools/pioasm to go from uart_tx.pio.h to uart_tx.h
