#![deny(unsafe_code)] #![no_std] #![no_main] use panic_halt as _; use nb::block; use cortex_m_rt::entry; use cortex_m_semihosting::hprintln; use stm32f4xx_hal::{gpio::PinState, pac, prelude::*, timer::Timer}; #[entry] fn main() -> ! { // Get access to the core peripherals from the cortex-m crate let cp = cortex_m::Peripherals::take().unwrap(); // Get access to the device specific peripherals from the peripheral access crate let dp = pac::Peripherals::take().unwrap(); // Take ownership over raw device and convert it into the corresponding HAL struct let rcc = dp.RCC.constrain(); // Freeze the configuration of all the clocks in the system and store the frozen frequencies in // `clocks` let clocks = rcc.cfgr.freeze(); // Acquire the GPIOC peripheral let gpioc = dp.GPIOC.split(); let mut pin = gpioc.pc13.into_dynamic(); // Configure the syst timer to trigger an update every second let mut timer = Timer::syst(cp.SYST, &clocks).counter_us(); timer.start(1.secs()).unwrap(); // Wait for the timer to trigger an update and change the state of the LED loop { pin.make_floating_input(); block!(timer.wait()).unwrap(); hprintln!("{}", pin.is_high().unwrap()); pin.make_push_pull_output_in_state(PinState::High); block!(timer.wait()).unwrap(); pin.set_low().unwrap(); block!(timer.wait()).unwrap(); } }