mirror of
https://github.com/italicsjenga/rp-hal-boards.git
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109 lines
3.1 KiB
Rust
109 lines
3.1 KiB
Rust
//! # UART Example
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//!
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//! This application demonstrates how to use the UART Driver to talk to a serial
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//! connection.
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//!
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//! It may need to be adapted to your particular board layout and/or pin
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//! assignment.
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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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// 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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// Alias for our HAL crate
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use rp2040_hal as hal;
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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 hal::pac;
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// Some traits we need
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use core::fmt::Write;
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use embedded_time::fixed_point::FixedPoint;
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use rp2040_hal::clocks::Clock;
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/// The linker will place this boot block at the start of our program image. We
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/// need this to help the ROM bootloader get our code up and running.
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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_W25Q080;
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/// External high-speed crystal on the Raspberry Pi Pico board is 12 MHz. Adjust
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/// if your board has a different frequency
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const XTAL_FREQ_HZ: u32 = 12_000_000u32;
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/// Entry point to our bare-metal application.
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///
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/// The `#[entry]` macro ensures the Cortex-M start-up code calls this function
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/// as soon as all global variables are initialised.
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///
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/// The function configures the RP2040 peripherals, then writes to the UART in
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/// an infinite loop.
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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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let core = pac::CorePeripherals::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::new(pac.WATCHDOG);
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// Configure the clocks
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let clocks = hal::clocks::init_clocks_and_plls(
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XTAL_FREQ_HZ,
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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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let mut delay = cortex_m::delay::Delay::new(core.SYST, clocks.system_clock.freq().integer());
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// The single-cycle I/O block controls our GPIO pins
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let sio = hal::Sio::new(pac.SIO);
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// Set the pins to their default state
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let pins = hal::gpio::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 uart_pins = (
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// UART TX (characters sent from RP2040) on pin 1 (GPIO0)
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pins.gpio0.into_mode::<hal::gpio::FunctionUart>(),
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// UART RX (characters received by RP2040) on pin 2 (GPIO1)
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pins.gpio1.into_mode::<hal::gpio::FunctionUart>(),
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);
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let mut uart = hal::uart::UartPeripheral::new(pac.UART0, uart_pins, &mut pac.RESETS)
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.enable(
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hal::uart::common_configs::_9600_8_N_1,
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clocks.peripheral_clock.into(),
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)
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.unwrap();
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uart.write_full_blocking(b"UART example\r\n");
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let mut value = 0u32;
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loop {
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writeln!(uart, "value: {:02}\r", value).unwrap();
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delay.delay_ms(1000);
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value += 1
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}
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}
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// End of file
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