Module f3::examples::_7_resource
[−]
[src]
Sharing memory using Resource
This builds on top of the concurrent
example. The loopback
task now
additionally parses the received data as a command. Two commands are
available:
reverse
- reverses the spin direction of the LED roulettereset
- moves the roulette back to its start position (North)
#![feature(const_fn)] #![feature(used)] #![no_std] // version = "0.2.0", default-features = false extern crate cast; // version = "0.2.0" extern crate cortex_m_rt; // version = "0.1.0" #[macro_use] extern crate cortex_m_rtfm as rtfm; extern crate f3; // version = "0.1.0" extern crate heapless; use core::cell::Cell; use cast::{u8, usize}; use f3::led::{self, LEDS}; use f3::serial::Serial; use f3::stm32f30x::interrupt::{Tim7, Usart1Exti25}; use f3::stm32f30x; use f3::timer::Timer; use heapless::Vec; use rtfm::{C0, C1, C16, Local, P0, P1, Resource}; #[derive(Clone, Copy)] enum Direction { Clockwise, Counterclockwise, } struct Command { direction: Cell<Direction>, reset: Cell<bool>, } impl Command { const fn new() -> Command { Command { direction: Cell::new(Direction::Clockwise), reset: Cell::new(false), } } } // CONFIGURATION pub const BAUD_RATE: u32 = 115_200; // bits per second const FREQUENCY: u32 = 4; // Hz // RESOURCES peripherals!(stm32f30x, { GPIOA: Peripheral { register_block: Gpioa, ceiling: C0, }, GPIOE: Peripheral { register_block: Gpioe, ceiling: C0, }, RCC: Peripheral { register_block: Rcc, ceiling: C0, }, TIM7: Peripheral { register_block: Tim7, ceiling: C1, }, USART1: Peripheral { register_block: Usart1, ceiling: C1, }, }); static COMMAND: Resource<Command, C1> = Resource::new(Command::new()); // INITIALIZATION PHASE fn init(ref prio: P0, ceil: &C16) { let gpioa = GPIOA.access(prio, ceil); let gpioe = GPIOE.access(prio, ceil); let rcc = RCC.access(prio, ceil); let tim7 = TIM7.access(prio, ceil); let timer = Timer(&tim7); let usart1 = USART1.access(prio, ceil); led::init(&gpioe, &rcc); timer.init(&rcc, FREQUENCY); Serial(&usart1).init(&gpioa, &rcc, BAUD_RATE); timer.resume(); } // IDLE LOOP fn idle(_prio: P0, _ceil: C0) -> ! { // Sleep loop { rtfm::wfi(); } } // TASKS tasks!(stm32f30x, { roulette: Task { interrupt: Tim7, priority: P1, enabled: true, }, receive: Task { interrupt: Usart1Exti25, priority: P1, enabled: true, }, }); fn receive(mut task: Usart1Exti25, ref prio: P1, ref ceil: C1) { static BUFFER: Local<Vec<u8, [u8; 16]>, Usart1Exti25> = { Local::new(Vec::new([0; 16])) }; let usart1 = USART1.access(prio, ceil); let serial = Serial(&usart1); if let Ok(byte) = serial.read() { if serial.write(byte).is_err() { // As we are echoing the bytes as soon as they arrive, it should // be impossible to have a TX buffer overrun #[cfg(debug_assertions)] unreachable!() } let buffer = BUFFER.borrow_mut(&mut task); if byte == b'r' { // end of command let command = COMMAND.access(prio, ceil); match &**buffer { b"reverse" => { let Command { ref direction, .. } = *command; match direction.get() { Direction::Clockwise => { direction.set(Direction::Counterclockwise) } Direction::Counterclockwise => { direction.set(Direction::Clockwise) } } } b"reset" => { command.reset.set(true); } _ => {} } buffer.clear(); } else { if buffer.push(byte).is_err() { // TODO proper error handling // for now we just clear the buffer when full buffer.clear(); } } } else { // Only reachable through `rtfm::request(receive)` #[cfg(debug_assertions)] unreachable!() } } fn roulette(mut task: Tim7, ref prio: P1, ref ceil: C1) { static STATE: Local<u8, Tim7> = Local::new(0); let tim7 = TIM7.access(prio, ceil); let timer = Timer(&tim7); if timer.clear_update_flag().is_ok() { let state = STATE.borrow_mut(&mut task); let curr = *state; let command = COMMAND.access(prio, ceil); let direction = command.direction.get(); let Command { ref reset, .. } = *command; let n = u8(LEDS.len()).unwrap(); let next = if reset.get() { reset.set(false); 0 } else { match direction { Direction::Clockwise => (curr + 1) % n, Direction::Counterclockwise => { curr.checked_sub(1).unwrap_or(n - 1) } } }; LEDS[usize(curr)].off(); LEDS[usize(next)].on(); *state = next; } else { // Only reachable through `rtfm::request(roulette)` #[cfg(debug_assertion)] unreachable!() } }