Crate pio

Expand description

Programmable Input/Output

// Repeatedly get one word of data from the TX FIFO, stalling when
// the FIFO is empty. Write the least significant bit to the OUT pin
// group.
// https://github.com/raspberrypi/pico-examples/tree/master/pio/hello_pio/hello.pio
let mut a = pio::Assembler::<{ pio::RP2040_MAX_PROGRAM_SIZE }>::new();

let mut loop_label = a.label();

a.bind(&mut loop_label);
a.pull(false, false);
a.out(pio::OutDestination::PINS, 1);
a.jmp(pio::JmpCondition::Always, &mut loop_label);

let program = a.assemble_program();

Wrapping

let mut a = pio::Assembler::<{ pio::RP2040_MAX_PROGRAM_SIZE }>::new();

let mut wrap_source = a.label();
let mut wrap_target = a.label();

// Initialize pin direction only once
a.set(pio::SetDestination::PINDIRS, 1);
a.bind(&mut wrap_target);
a.out(pio::OutDestination::PINS, 1);
a.bind(&mut wrap_source);

let program = a.assemble_with_wrap(wrap_source, wrap_target);