123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113 |
- // blinky timer using interrupts on TIM2
- //
- // This demo based off of the following demo:
- // - https://github.com/stm32-rs/stm32f0xx-hal/blob/master/examples/blinky_timer_irq.rs
- // with some information about STM32F1 interrupts/peripherals from:
- // - https://github.com/geomatsi/rust-blue-pill-tests/blob/master/src/bin/blink-timer-irq-safe.rs
- #![no_main]
- #![no_std]
- use panic_halt as _;
- use stm32f1xx_hal as hal;
- use crate::hal::{
- gpio::*,
- pac::{interrupt, Interrupt, Peripherals, TIM2},
- prelude::*,
- timer::*,
- };
- use core::cell::RefCell;
- use cortex_m::{asm::wfi, interrupt::Mutex, peripheral::Peripherals as c_m_Peripherals};
- use cortex_m_rt::entry;
- // NOTE You can uncomment 'hprintln' here and in the code below for a bit more
- // verbosity at runtime, at the cost of throwing off the timing of the blink
- // (using 'semihosting' for printing debug info anywhere slows program
- // execution down)
- //use cortex_m_semihosting::hprintln;
- // A type definition for the GPIO pin to be used for our LED
- type LEDPIN = gpioc::PC13<Output<PushPull>>;
- // Make LED pin globally available
- static G_LED: Mutex<RefCell<Option<LEDPIN>>> = Mutex::new(RefCell::new(None));
- // Make timer interrupt registers globally available
- static G_TIM: Mutex<RefCell<Option<CountDownTimer<TIM2>>>> = Mutex::new(RefCell::new(None));
- // Define an interupt handler, i.e. function to call when interrupt occurs.
- // This specific interrupt will "trip" when the timer TIM2 times out
- #[interrupt]
- fn TIM2() {
- static mut LED: Option<LEDPIN> = None;
- static mut TIM: Option<CountDownTimer<TIM2>> = None;
- let led = LED.get_or_insert_with(|| {
- cortex_m::interrupt::free(|cs| {
- // Move LED pin here, leaving a None in its place
- G_LED.borrow(cs).replace(None).unwrap()
- })
- });
- let tim = TIM.get_or_insert_with(|| {
- cortex_m::interrupt::free(|cs| {
- // Move LED pin here, leaving a None in its place
- G_TIM.borrow(cs).replace(None).unwrap()
- })
- });
- //hprintln!("TIM2 IRQ fired").unwrap();
- led.toggle().ok();
- tim.wait().ok();
- }
- #[entry]
- fn main() -> ! {
- if let (Some(dp), Some(cp)) = (Peripherals::take(), c_m_Peripherals::take()) {
- cortex_m::interrupt::free(move |cs| {
- let mut rcc = dp.RCC.constrain();
- let mut flash = dp.FLASH.constrain();
- let clocks = rcc
- .cfgr
- .sysclk(8.mhz())
- .pclk1(8.mhz())
- .freeze(&mut flash.acr);
- // Configure PC13 pin to blink LED
- let mut gpioc = dp.GPIOC.split(&mut rcc.apb2);
- let led = gpioc.pc13.into_push_pull_output(&mut gpioc.crh);
- // Move the pin into our global storage
- *G_LED.borrow(cs).borrow_mut() = Some(led);
- // Set up a timer expiring after 1s
- let mut timer = Timer::tim2(dp.TIM2, &clocks, &mut rcc.apb1).start_count_down(1.hz());
- // Generate an interrupt when the timer expires
- timer.listen(Event::Update);
- // Move the timer into our global storage
- *G_TIM.borrow(cs).borrow_mut() = Some(timer);
- // Enable TIM2 IRQ, set prio 1 and clear any pending IRQs
- let mut nvic = cp.NVIC;
- // Calling 'set_priority()' and 'unmask()' requires 'unsafe {}'
- // - https://docs.rs/stm32f1xx-hal/0.5.3/stm32f1xx_hal/stm32/struct.NVIC.html#method.set_priority
- unsafe {
- nvic.set_priority(Interrupt::TIM2, 1);
- cortex_m::peripheral::NVIC::unmask(Interrupt::TIM2);
- }
- // Clear the interrupt state
- cortex_m::peripheral::NVIC::unpend(Interrupt::TIM2);
- });
- }
- //hprintln!("Entering main loop...").unwrap();
- loop {
- // From 'cortex_m::asm::wfi'
- wfi();
- }
- }
|