mirror of
https://github.com/italicsjenga/rp-hal-boards.git
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93 lines
2.5 KiB
Rust
93 lines
2.5 KiB
Rust
//! # Pico Countdown Blinky Example
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//!
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//! Blinks the LED on a Pico board, using an RP2040 Timer in Count-down mode.
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//!
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//! This will blink an LED attached to GP25, which is the pin the Pico uses for
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//! the on-board LED.
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//!
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//! See the `Cargo.toml` file for Copyright and licence details.
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#![no_std]
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#![no_main]
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// The macro for our start-up function
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use cortex_m_rt::entry;
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use cortex_m::prelude::*;
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// GPIO traits
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use embedded_hal::digital::v2::OutputPin;
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// Traits for converting integers to amounts of time
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use embedded_time::duration::Extensions;
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// Ensure we halt the program on panic (if we don't mention this crate it won't
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// be linked)
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use panic_halt as _;
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// A shorter alias for the Peripheral Access Crate, which provides low-level
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// register access
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use pico::hal::pac;
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// A shorter alias for the Hardware Abstraction Layer, which provides
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// higher-level drivers.
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use pico::hal;
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#[link_section = ".boot2"]
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#[used]
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pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER;
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#[entry]
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fn main() -> ! {
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// Grab our singleton objects
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let mut pac = pac::Peripherals::take().unwrap();
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// Set up the watchdog driver - needed by the clock setup code
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let mut watchdog = hal::watchdog::Watchdog::new(pac.WATCHDOG);
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// Configure the clocks
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//
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// The default is to generate a 125 MHz system clock
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let _clocks = hal::clocks::init_clocks_and_plls(
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pico::XOSC_CRYSTAL_FREQ,
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pac.XOSC,
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pac.CLOCKS,
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pac.PLL_SYS,
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pac.PLL_USB,
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&mut pac.RESETS,
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&mut watchdog,
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)
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.ok()
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.unwrap();
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// Configure the Timer peripheral in count-down mode
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let timer = hal::timer::Timer::new(pac.TIMER, &mut pac.RESETS);
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let mut count_down = timer.count_down();
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// The single-cycle I/O block controls our GPIO pins
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let sio = hal::sio::Sio::new(pac.SIO);
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// Set the pins up according to their function on this particular board
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let pins = pico::Pins::new(
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pac.IO_BANK0,
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pac.PADS_BANK0,
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sio.gpio_bank0,
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&mut pac.RESETS,
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);
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let mut led_pin = pins.led.into_push_pull_output();
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// Blink the LED at 1 Hz
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loop {
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// LED on, and wait for 500ms
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led_pin.set_high().unwrap();
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count_down.start(500.milliseconds());
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let _ = nb::block!(count_down.wait());
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// LED off, and wait for 500ms
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led_pin.set_low().unwrap();
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count_down.start(500.milliseconds());
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let _ = nb::block!(count_down.wait());
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}
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}
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