rp-hal-boards/rp2040-hal/examples/pio_proc_blink.rs
Wilfried Chauveau 0e2b4cf7be
Add a method to allow setting the PIO's clock divisor without floats (#440)
* pio: Changes `PIOBuilder::clock_divisor` from f32 to fixed point)
* pio: mark clock_divisor as deprecated
2022-08-31 21:44:53 +01:00

64 lines
1.9 KiB
Rust

//! This example toggles the GPIO25 pin, using a PIO program compiled via pio_proc::pio!().
//!
//! If a LED is connected to that pin, like on a Pico board, the LED should blink.
#![no_std]
#![no_main]
use hal::gpio::{FunctionPio0, Pin};
use hal::pac;
use hal::pio::PIOExt;
use hal::Sio;
use panic_halt as _;
use rp2040_hal as hal;
#[link_section = ".boot2"]
#[used]
pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_GENERIC_03H;
/// Entry point to our bare-metal application.
///
/// The `#[rp2040_hal::entry]` macro ensures the Cortex-M start-up code calls this function
/// as soon as all global variables and the spinlock are initialised.
#[rp2040_hal::entry]
fn main() -> ! {
let mut pac = pac::Peripherals::take().unwrap();
let sio = Sio::new(pac.SIO);
let pins = hal::gpio::Pins::new(
pac.IO_BANK0,
pac.PADS_BANK0,
sio.gpio_bank0,
&mut pac.RESETS,
);
// configure LED pin for Pio0.
let _led: Pin<_, FunctionPio0> = pins.gpio25.into_mode();
// PIN id for use inside of PIO
let led_pin_id = 25;
// Define some simple PIO program.
let program = pio_proc::pio_asm!(
".wrap_target",
"set pins, 1 [31]",
"set pins, 0 [31]",
".wrap"
);
// Initialize and start PIO
let (mut pio, sm0, _, _, _) = pac.PIO0.split(&mut pac.RESETS);
let installed = pio.install(&program.program).unwrap();
let (int, frac) = (0, 0); // as slow as possible (0 is interpreted as 65536)
let (mut sm, _, _) = rp2040_hal::pio::PIOBuilder::from_program(installed)
.set_pins(led_pin_id, 1)
.clock_divisor_fixed_point(int, frac)
.build(sm0);
// The GPIO pin needs to be configured as an output.
sm.set_pindirs([(led_pin_id, hal::pio::PinDir::Output)]);
sm.start();
// PIO runs in background, independently from CPU
loop {
cortex_m::asm::wfi();
}
}