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#![no_std]
#![no_main]
// required-features: can
#[path = "../common.rs"]
mod common;
use common::*;
use defmt::assert;
use embassy_executor::Spawner;
use embassy_stm32::bind_interrupts;
use embassy_stm32::can::bxcan::filter::Mask32;
use embassy_stm32::can::bxcan::{Fifo, Frame, StandardId};
use embassy_stm32::can::{Can, Rx0InterruptHandler, Rx1InterruptHandler, SceInterruptHandler, TxInterruptHandler};
use embassy_stm32::gpio::{Input, Pull};
use embassy_stm32::peripherals::CAN1;
use embassy_time::{Duration, Instant};
use {defmt_rtt as _, panic_probe as _};
bind_interrupts!(struct Irqs {
CAN1_RX0 => Rx0InterruptHandler<CAN1>;
CAN1_RX1 => Rx1InterruptHandler<CAN1>;
CAN1_SCE => SceInterruptHandler<CAN1>;
CAN1_TX => TxInterruptHandler<CAN1>;
});
#[embassy_executor::main]
async fn main(_spawner: Spawner) {
let p = embassy_stm32::init(config());
info!("Hello World!");
let can = peri!(p, CAN);
let tx = peri!(p, CAN_TX);
let mut rx = peri!(p, CAN_RX);
// The next two lines are a workaround for testing without transceiver.
// To synchronise to the bus the RX input needs to see a high level.
// Use `mem::forget()` to release the borrow on the pin but keep the
// pull-up resistor enabled.
let rx_pin = Input::new(&mut rx, Pull::Up);
core::mem::forget(rx_pin);
let mut can = Can::new(can, rx, tx, Irqs);
info!("Configuring can...");
can.as_mut()
.modify_filters()
.enable_bank(0, Fifo::Fifo0, Mask32::accept_all());
can.set_bitrate(1_000_000);
can.as_mut()
.modify_config()
.set_loopback(true) // Receive own frames
.set_silent(true)
// .set_bit_timing(0x001c0003)
.enable();
info!("Can configured");
let mut i: u8 = 0;
loop {
let tx_frame = Frame::new_data(unwrap!(StandardId::new(i as _)), [i]);
info!("Transmitting frame...");
let tx_ts = Instant::now();
can.write(&tx_frame).await;
let envelope = can.read().await.unwrap();
info!("Frame received!");
info!("loopback time {}", envelope.ts);
info!("loopback frame {=u8}", envelope.frame.data().unwrap()[0]);
let latency = envelope.ts.saturating_duration_since(tx_ts);
info!("loopback latency {} us", latency.as_micros());
// Theoretical minimum latency is 55us, actual is usually ~80us
const MIN_LATENCY: Duration = Duration::from_micros(50);
const MAX_LATENCY: Duration = Duration::from_micros(150);
assert!(
MIN_LATENCY <= latency && latency <= MAX_LATENCY,
"{} <= {} <= {}",
MIN_LATENCY,
latency,
MAX_LATENCY
);
i += 1;
if i > 10 {
break;
}
}
info!("Test OK");
cortex_m::asm::bkpt();
}
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