63 lines
2.1 KiB
Rust
63 lines
2.1 KiB
Rust
//! Blinks an LED
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//!
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//! This assumes that a LED is connected to pc13 as is the case on the blue pill board.
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//!
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//! Note: Without additional hardware, PC13 should not be used to drive an LED, see page 5.1.2 of
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//! the reference manual for an explanation. This is not an issue on the blue pill.
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#![deny(unsafe_code)]
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#![no_std]
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#![cfg_attr(not(doc), no_main)]
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use panic_rtt_target as _;
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use rtt_target::{rprintln, rtt_init_print};
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use nb::block;
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use cortex_m_rt::entry;
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use stm32f1xx_hal::{pac, prelude::*, timer::Timer};
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#[entry]
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fn main() -> ! {
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// Init buffers for debug printing
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rtt_init_print!();
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// Get access to the core peripherals from the cortex-m crate
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let cp = cortex_m::Peripherals::take().unwrap();
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// Get access to the device specific peripherals from the peripheral access crate
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let dp = pac::Peripherals::take().unwrap();
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// Take ownership over the raw flash and rcc devices and convert them into the corresponding
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// HAL structs
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let mut flash = dp.FLASH.constrain();
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let rcc = dp.RCC.constrain();
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// Freeze the configuration of all the clocks in the system and store the frozen frequencies in
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// `clocks`
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let clocks = rcc.cfgr.freeze(&mut flash.acr);
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// Acquire the GPIOC peripheral
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let mut gpioc = dp.GPIOC.split();
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// Configure gpio C pin 13 as a push-pull output. The `crh` register is passed to the function
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// in order to configure the port. For pins 0-7, crl should be passed instead.
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let mut led = gpioc.pc13.into_push_pull_output(&mut gpioc.crh);
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// Configure the syst timer to trigger an update every second
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let mut timer = Timer::syst(cp.SYST, &clocks).counter_hz();
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timer.start(1.Hz()).unwrap();
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rprintln!("Hello, Rust!");
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// Wait for the timer to trigger an update and change the state of the LED
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let mut i = 0;
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loop {
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block!(timer.wait()).unwrap();
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led.set_high();
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block!(timer.wait()).unwrap();
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led.set_low();
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i += 1;
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rprintln!("Hello again; I have blinked {} times.", i);
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if i == 10 {
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panic!("Yow, 10 times is enough!");
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}
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}
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}
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