2 files changed, 53 insertions, 0 deletions

diff --git a/examples/stm32f4/Cargo.toml b/examples/stm32f4/Cargo.toml
index c254573f8..95c8441d9 100644
--- a/examples/stm32f4/Cargo.toml
+++ b/examples/stm32f4/Cargo.toml
@@ -32,3 +32,4 @@ panic-probe = { version = "0.2.0", features= ["print-defmt"] }
 futures = { version = "0.3.8", default-features = false, features = ["async-await"] }
 rtt-target = { version = "0.3", features = ["cortex-m"] }
 heapless = { version = "0.7.1", default-features = false }
+nb = { version = "1.0" }
diff --git a/examples/stm32f4/src/bin/can.rs b/examples/stm32f4/src/bin/can.rs
new file mode 100644
index 000000000..2bb24f045
--- /dev/null
+++ b/examples/stm32f4/src/bin/can.rs
@@ -0,0 +1,52 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+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]
+fn main() -> ! {
+    info!("Hello World!");
+
+    unsafe {
+        Dbgmcu::enable_all();
+    }
+
+    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_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;
+    loop {
+        let tx_frame = Frame::new_data(unwrap!(StandardId::new(i as _)), [i]);
+        unwrap!(nb::block!(can.transmit(&tx_frame)));
+        while !can.is_transmitter_idle() {}
+        let rx_frame = unwrap!(nb::block!(can.receive()));
+        info!("loopback frame {=u8}", unwrap!(rx_frame.data())[0]);
+        i += 1;
+    }
+}