From dacf75d911058dd09d2a825a5b23d758f1f7a92d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timo=20Kr=C3=B6ger?= Date: Mon, 9 Aug 2021 15:59:05 +0200 Subject: [PATCH] bxcan: Fix the flaky CAN example --- examples/stm32f4/src/bin/can.rs | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/examples/stm32f4/src/bin/can.rs b/examples/stm32f4/src/bin/can.rs index 04f3417c..2bb24f04 100644 --- a/examples/stm32f4/src/bin/can.rs +++ b/examples/stm32f4/src/bin/can.rs @@ -8,8 +8,10 @@ mod example_common; use cortex_m_rt::entry; +use embassy_stm32::can::filter::Mask32; use embassy_stm32::can::{Can, Frame, StandardId}; use embassy_stm32::dbgmcu::Dbgmcu; +use embassy_stm32::gpio::{Input, Pull}; use example_common::*; #[entry] @@ -20,11 +22,22 @@ fn main() -> ! { Dbgmcu::enable_all(); } - let p = embassy_stm32::init(Default::default()); + let mut p = embassy_stm32::init(Default::default()); + + // 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 p.PA11, Pull::Up); + core::mem::forget(rx_pin); let mut can = Can::new(p.CAN1, p.PA11, p.PA12); - can.modify_config().set_loopback(true); + can.modify_config() + .set_bit_timing(0x001c0003) // http://www.bittiming.can-wiki.info/ + .set_loopback(true) // Receive own frames + .set_silent(true); + can.modify_filters().enable_bank(0, Mask32::accept_all()); unwrap!(nb::block!(can.enable())); let mut i: u8 = 0;