rp-hal-boards/boards/pico/examples/pico_gpio_in_out.rs

//! Toggle LED based on GPIO input
//!
//! This will control an LED on GP25 based on a button hooked up to GP15. The button should be tied
//! to ground, as the input pin is pulled high internally by this example. When the button is
//! pressed, the LED will turn off.
#![no_std]
#![no_main]

use cortex_m_rt::entry;
use embedded_hal::digital::v2::{InputPin, OutputPin};
use hal::pac;
use hal::sio::Sio;
use panic_halt as _;
use pico::{hal, Pins};

#[link_section = ".boot2"]
#[used]
pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER;

#[entry]
fn main() -> ! {
    let mut pac = pac::Peripherals::take().unwrap();

    let sio = Sio::new(pac.SIO);
    let pins = Pins::new(
        pac.IO_BANK0,
        pac.PADS_BANK0,
        sio.gpio_bank0,
        &mut pac.RESETS,
    );
    let mut led_pin = pins.led.into_push_pull_output();
    let button_pin = pins.bootsel.into_pull_down_input();

    loop {
        if button_pin.is_low().unwrap() {
            led_pin.set_high().unwrap();
        } else {
            led_pin.set_low().unwrap();
        }
    }
}