double linked list can driver

canome/Cargo.toml

@@ -11,16 +11,24 @@ keywords = [ "CAN", "embedded", "smarthome" ]
 [dependencies]
 defmt = "0.3"
 
-heapless = { version = "0.8.0", default-features = false }
+heapless = { version = "0.8", default-features = false }
-critical-section = "1.0"
+critical-section = "1.1"
 
-embedded-hal = { version = "0.2.7", optional = true }
+embedded-hal = { version = "0.2", optional = true }
-stm32f1xx-hal = { version = "0.10.0", optional = true }
+stm32f1xx-hal = { version = "0.10", optional = true }
-rtic-monotonics = { version = "1.0.0", optional = true }
+rtic-monotonics = { version = "1.0", optional = true }
-bxcan = { version = "0.7.0", optional = true }
+bxcan = { version = "0.7", optional = true }
-nb = "1.1.0"
+socketcan = { version = "3.3", default-features = false, optional = true }
+nb = "1.1"
+once_cell = { version = "1.19.0", default-features = false, features = ["critical-section"] }
+
+embedded-can = "0.4"
 
 [features]
-default = [ "can", "stm32" ]
+default = [ "bxcan" ]
-can = [ "dep:bxcan" ]
+bxcan = [ "dep:bxcan" ]
+socketcan = [ "dep:socketcan" ]
 stm32 = [ "dep:embedded-hal", "dep:stm32f1xx-hal", "dep:rtic-monotonics", "dep:bxcan" ]
+
+[dev-dependencies]
+critical-section = { version = "1.1", features = ["std"]}

canome/src/bus.rs

@@ -1,291 +1,184 @@
 use core::{
-    cell::RefCell,
+    cell::{Cell, RefCell},
     fmt::Debug,
-    future::{poll_fn, Future},
+    future::poll_fn,
     marker::PhantomData,
     task::{Poll, Waker},
 };
 
 use critical_section::Mutex;
-use heapless::{LinearMap, Vec};
+use defmt::warn;
+use embedded_can::Id;
+use heapless::Deque;
+use once_cell::sync::OnceCell;
 
-use crate::{BusBackend, Channel, Decode, Encode};
+use crate::{CanDataFormat, Channel, Decode, Encode};
 
-pub struct Bus<B: BusBackend, const CHANNELS: usize, const WAKER_CAP: usize> {
+pub(crate) struct ReceiverInner {
-    rx_queues: critical_section::Mutex<RefCell<LinearMap<B::ID, BusInner<B, WAKER_CAP>, CHANNELS>>>,
+    pub(crate) id: Id,
-    backend: B,
+    pub(crate) queue: Mutex<RefCell<Deque<CanDataFormat, 8>>>,
+    pub(crate) waker: Mutex<Cell<Option<Waker>>>,
+}
+pub(crate) struct TransmitterInner {
+    pub(crate) id: Id,
+    pub(crate) remote_received: Mutex<Cell<bool>>,
+    pub(crate) waker: Mutex<Cell<Option<Waker>>>,
+}
+
+pub struct UnboundReceiver<'a> {
+    pub(crate) bus: &'a dyn Bus,
+    pub(crate) inner: &'a OnceCell<ReceiverInner>,
+}
+
+pub struct BoundReceiver<'a, C: Channel> {
+    pub(crate) bus: &'a dyn Bus,
+    pub(crate) _channel: PhantomData<C>,
+    pub(crate) inner: &'a ReceiverInner,
+}
+
+pub struct UnboundTransmitter<'a> {
+    pub(crate) bus: &'a dyn Bus,
+    pub(crate) inner: &'a OnceCell<TransmitterInner>,
+}
+
+pub struct BoundTransmitter<'a, C: Channel> {
+    pub(crate) bus: &'a dyn Bus,
+    pub(crate) _channel: PhantomData<C>,
+    pub(crate) inner: &'a TransmitterInner,
 }
 
 #[derive(Debug)]
-pub enum BusError<B: BusBackend> {
+pub enum BusError {
-    Backend(B::Error),
     ChannelCapExceeded,
 }
 
-#[derive(Debug)]
+pub trait Bus: Send + Sync {
-struct BusInner<B: BusBackend, const WAKER_CAP: usize> {
+    fn transmit(&self, id: Id, value: CanDataFormat) -> Result<(), BusError>;
-    state: B::Data,
+    fn request(&self, id: Id) -> Result<(), BusError>;
-    wakers: Vec<Waker, WAKER_CAP>,
+
-    sender: bool,
+    fn distribute_data(&self, id: Id, value: CanDataFormat);
+    fn distribute_remote(&self, id: Id);
 }
 
-#[derive(Clone)]
+impl<'a> UnboundTransmitter<'a> {
-pub struct BusChannelTransceiver<'a, B: BusBackend, C: Channel<B>> {
+    pub fn bind<C: Channel>(self) -> BoundTransmitter<'a, C> {
-    bus: &'a dyn BusBehaviour<B>,
+        self.inner.set(TransmitterInner {
-    _channel: PhantomData<C>,
+            id: C::ID,
+            remote_received: Mutex::new(Cell::new(false)),
+            waker: Mutex::new(Cell::new(None)),
+        });
+        self.bus.request(C::ID);
+        BoundTransmitter {
+            bus: self.bus,
+            _channel: PhantomData,
+            inner: &self.inner.get().unwrap(),
+        }
+    }
 }
-#[derive(Clone)]
+impl<'a> UnboundReceiver<'a> {
-pub struct BusChannelReceiver<'a, B: BusBackend, C: Channel<B>> {
+    pub fn bind<C: Channel>(self) -> BoundReceiver<'a, C> {
-    bus: &'a dyn BusBehaviour<B>,
+        self.inner.set(ReceiverInner {
-    _channel: PhantomData<C>,
+            id: C::ID,
-}
+            queue: Mutex::new(RefCell::new(Deque::new())),
-
+            waker: Mutex::new(Cell::new(None)),
-pub trait BusBehaviour<B: BusBackend> {
+        });
-    fn get(&self, id: B::ID) -> Option<B::Data>;
+        self.bus.request(C::ID);
-    fn register_waker(&self, id: B::ID, waker: &Waker);
+        BoundReceiver {
-    fn publish(&self, id: B::ID, value: B::Data) -> Result<(), BusError<B>>;
+            bus: self.bus,
-    fn publish_local(&self, id: &B::ID, value: B::Data);
+            _channel: PhantomData,
-    fn request(&self, id: B::ID) -> Result<(), BusError<B>>;
+            inner: &self.inner.get().unwrap(),
-}
-
-impl<B: BusBackend, T: BusBehaviour<B>> BusBehaviour<B> for &T {
-    fn get(&self, id: <B as BusBackend>::ID) -> Option<<B as BusBackend>::Data> {
-        (*self).get(id)
         }
-
-    fn register_waker(&self, id: <B as BusBackend>::ID, waker: &Waker) {
-        (*self).register_waker(id, waker)
-    }
-
-    fn publish(
-        &self,
-        id: <B as BusBackend>::ID,
-        value: <B as BusBackend>::Data,
-    ) -> Result<(), BusError<B>> {
-        (*self).publish(id, value)
-    }
-
-    fn publish_local(&self, id: &<B as BusBackend>::ID, value: <B as BusBackend>::Data) {
-        (*self).publish_local(id, value)
-    }
-
-    fn request(&self, id: <B as BusBackend>::ID) -> Result<(), BusError<B>> {
-        (*self).request(id)
     }
 }
 
-pub trait BusRx<C: Channel<B>, B: BusBackend> {
+impl<'a, C: Channel> BoundReceiver<'a, C>
-    fn get(&self) -> C::State;
-    fn request(&self) -> Result<(), BusError<B>>;
-    fn next(&self) -> impl Future<Output = C::State>;
-}
-
-pub trait BusTx<C: Channel<B>, B: BusBackend> {
-    fn publish(&self, value: C::State) -> Result<(), BusError<B>>;
-}
-
-impl<B: BusBackend, const CHANNELS: usize, const WAKER_CAP: usize> BusBehaviour<B>
-    for Bus<B, CHANNELS, WAKER_CAP>
 where
-    B::ID: Eq,
+    C::Message: Decode<CanDataFormat> + Encode<CanDataFormat>,
 {
-    fn get(&self, id: B::ID) -> Option<B::Data> {
+    pub fn request(&self) -> Result<(), BusError> {
+        self.bus.request(C::ID)
+    }
+    pub fn try_recv(&self) -> Option<C::Message> {
         critical_section::with(|cs| {
-            self.rx_queues
+            match self
+                .inner
+                .queue
                 .borrow(cs)
                 .borrow_mut()
-                .get_mut(&id)
+                .pop_back()
-                .map(|x| x.state.clone())
+                .map(C::Message::decode)
-        })
+            {
-    }
+                Some(Ok(frame)) => Some(frame),
-
+                Some(Err(_)) => {
-    fn register_waker(&self, id: B::ID, waker: &Waker) {
+                    warn!("Failed to decode Frame");
-        critical_section::with(|cs| {
+                    None
-            if let Some(inner) = self.rx_queues.borrow(cs).borrow_mut().get_mut(&id) {
-                if inner.wakers.iter().any(|ew| waker.will_wake(ew)) {
-                    return;
-                }
-
-                if inner.wakers.is_full() {
-                    inner.wake();
-                }
-
-                if inner.wakers.push(waker.clone()).is_err() {
-                    panic!("tried to push a waker to a zero length waker list");
                 }
+                None => None,
             }
         })
     }
+    pub async fn recv(&self) -> C::Message {
+        poll_fn(|cx| {
+            let frame = critical_section::with(|cs| {
+                let existing_waker = self.inner.waker.borrow(cs);
 
-    fn publish(&self, id: B::ID, value: B::Data) -> Result<(), BusError<B>> {
+                let waker = match existing_waker.take() {
-        self.publish_local(&id, value.clone());
+                    Some(waker) if cx.waker().will_wake(&waker) => waker,
-
+                    Some(waker) => {
-        self.backend
+                        waker.wake();
-            .publish(id, Some(value))
+                        cx.waker().clone()
-            .map_err(BusError::Backend)
                     }
+                    None => cx.waker().clone(),
+                };
 
-    fn publish_local(&self, id: &B::ID, value: B::Data) {
+                existing_waker.set(Some(waker));
-        critical_section::with(|cs| {
+
-            if let Some(inner) = self.rx_queues.borrow(cs).borrow_mut().get_mut(id) {
+                self.inner.queue.borrow(cs).borrow_mut().pop_back()
-                inner.state = value.clone();
+            })
-                inner.wake();
+            .map(C::Message::decode);
+
+            match frame {
+                Some(Ok(frame)) => Poll::Ready(frame),
+                Some(Err(_)) => {
+                    warn!("Failed to decode Frame");
+                    Poll::Pending
                 }
+                None => Poll::Pending,
+            }
+        })
+        .await
+    }
+}
+
+impl<'a, C: Channel> BoundTransmitter<'a, C>
+where
+    C::Message: Decode<CanDataFormat> + Encode<CanDataFormat>,
+{
+    pub fn transmit(&self, value: C::Message) -> Result<(), BusError> {
+        let encoded = value.encode();
+        self.bus.transmit(C::ID, encoded)
+    }
+    pub async fn wait_remote(&self) {
+        poll_fn(|cx| {
+            let remote_received = critical_section::with(|cs| {
+                let existing_waker = self.inner.waker.borrow(cs);
+
+                let waker = match existing_waker.take() {
+                    Some(waker) if cx.waker().will_wake(&waker) => waker,
+                    Some(waker) => {
+                        waker.wake();
+                        cx.waker().clone()
+                    }
+                    None => cx.waker().clone(),
+                };
+                existing_waker.set(Some(waker));
+
+                self.inner.remote_received.borrow(cs).replace(false)
             });
-    }
 
-    fn request(&self, id: B::ID) -> Result<(), BusError<B>> {
+            match remote_received {
-        self.backend.publish(id, None).map_err(BusError::Backend)
+                true => Poll::Ready(()),
-    }
+                false => Poll::Pending,
-}
-
-impl<B: BusBackend, const WAKER_CAP: usize> BusInner<B, WAKER_CAP> {
-    fn wake(&mut self) {
-        let mut wakers = Vec::new();
-        core::mem::swap(&mut wakers, &mut self.wakers);
-        wakers.into_iter().for_each(|w| w.wake());
-    }
-}
-
-impl<B: BusBackend, const SUBS: usize, const WAKER_CAP: usize> Bus<B, SUBS, WAKER_CAP>
-where
-    B::ID: Eq,
-{
-    pub const fn new(backend: B) -> Self {
-        Self {
-            rx_queues: Mutex::new(RefCell::new(LinearMap::new())),
-            backend,
-        }
-    }
-
-    pub fn transceiver<C: Channel<B>>(&self) -> Result<BusChannelTransceiver<'_, B, C>, BusError<B>>
-    where
-        C::State: Default + Encode<B::Data>,
-    {
-        critical_section::with(|cs| {
-            let mut rx_queues = self.rx_queues.borrow(cs).borrow_mut();
-            if let Some(existing) = rx_queues.get_mut(&C::ID) {
-                existing.sender = true;
-                Ok(BusChannelTransceiver {
-                    bus: self,
-                    _channel: PhantomData,
-                })
-            } else if rx_queues.len() < SUBS {
-                self.request(C::ID).ok();
-                let _ = rx_queues.insert(
-                    C::ID,
-                    BusInner {
-                        state: C::State::default().encode(),
-                        wakers: Vec::new(),
-                        sender: true,
-                    },
-                );
-                Ok(BusChannelTransceiver {
-                    bus: self,
-                    _channel: PhantomData,
-                })
-            } else {
-                Err(BusError::ChannelCapExceeded)
-            }
-        })
-    }
-
-    pub fn receiver<C: Channel<B>>(&self) -> Result<BusChannelReceiver<'_, B, C>, BusError<B>>
-    where
-        C::State: Default + Encode<B::Data>,
-    {
-        critical_section::with(|cs| {
-            let mut rx_queues = self.rx_queues.borrow(cs).borrow_mut();
-            if rx_queues.contains_key(&C::ID) {
-                Ok(BusChannelReceiver {
-                    bus: self,
-                    _channel: PhantomData,
-                })
-            } else if rx_queues.len() < SUBS {
-                self.request(C::ID).ok();
-                let _ = rx_queues.insert(
-                    C::ID,
-                    BusInner {
-                        state: C::State::default().encode(),
-                        wakers: Vec::new(),
-                        sender: false,
-                    },
-                );
-                Ok(BusChannelReceiver {
-                    bus: self,
-                    _channel: PhantomData,
-                })
-            } else {
-                Err(BusError::ChannelCapExceeded)
-            }
-        })
-    }
-
-    pub fn backend(&self) -> &B {
-        &self.backend
-    }
-}
-
-impl<'a, B: BusBackend, C: Channel<B>> BusTx<C, B> for BusChannelTransceiver<'a, B, C>
-where
-    C::State: Encode<B::Data>,
-{
-    fn publish(&self, value: C::State) -> Result<(), BusError<B>> {
-        self.bus.publish(C::ID, value.encode())
-    }
-}
-
-impl<'a, B: BusBackend, C> BusRx<C, B> for BusChannelTransceiver<'a, B, C>
-where
-    C::State: Decode<B::Data> + PartialEq + Default,
-    C: Channel<B>,
-{
-    fn get(&self) -> C::State {
-        self.bus
-            .get(C::ID)
-            .and_then(|x| C::State::decode(x).ok())
-            .expect("valid group")
-    }
-    fn request(&self) -> Result<(), BusError<B>> {
-        self.bus.request(C::ID)
-    }
-    async fn next(&self) -> C::State {
-        let old_state: C::State = self.get();
-        poll_fn(|cx| {
-            self.bus.register_waker(C::ID, cx.waker());
-
-            let state: C::State = self.get();
-            match state == old_state {
-                false => Poll::Ready(state),
-                true => Poll::Pending,
-            }
-        })
-        .await
-    }
-}
-impl<'a, B: BusBackend, C> BusRx<C, B> for BusChannelReceiver<'a, B, C>
-where
-    C::State: Decode<B::Data> + PartialEq + Default,
-    C: Channel<B>,
-{
-    fn get(&self) -> C::State {
-        self.bus
-            .get(C::ID)
-            .and_then(|x| C::State::decode(x).ok())
-            .expect("valid group")
-    }
-    fn request(&self) -> Result<(), BusError<B>> {
-        self.bus.request(C::ID)
-    }
-    async fn next(&self) -> C::State {
-        let old_state: C::State = self.get();
-        poll_fn(|cx| {
-            self.bus.register_waker(C::ID, cx.waker());
-
-            let state: C::State = self.get();
-            match state == old_state {
-                false => Poll::Ready(state),
-                true => Poll::Pending,
             }
         })
         .await

canome/src/bxcan.rs

@@ -0,0 +1,198 @@
+use core::{array, fmt::Debug, mem::MaybeUninit};
+
+use crate::{
+    bus::{Bus, BusError, ReceiverInner, TransmitterInner, UnboundReceiver, UnboundTransmitter},
+    CanDataFormat,
+};
+use bxcan::{Instance, Interrupt, Rx0, Tx};
+use embedded_can::{ExtendedId, Id, StandardId};
+use heapless::mpmc::MpMcQueue;
+use once_cell::sync::OnceCell;
+
+pub struct BxCanBus<I: Instance, const TQ: usize, const RQ: usize> {
+    transmitters: [OnceCell<TransmitterInner>; TQ],
+    receivers: [OnceCell<ReceiverInner>; RQ],
+    tx_queue: MpMcQueue<bxcan::Frame, 32>,
+    tx: Tx<I>,
+    rx: Rx0<I>,
+}
+
+#[derive(Debug)]
+pub enum BxCanBusError {
+    /// An object couldn't be added to the TX queue of [`BxCanBus`] because it is full.
+    TxQueueFull,
+}
+
+impl<I: Instance, const TQ: usize, const RQ: usize> BxCanBus<I, TQ, RQ> {
+    pub fn initialize(
+        bus: &mut MaybeUninit<Self>,
+    ) -> (
+        &Self,
+        [UnboundTransmitter<'_>; TQ],
+        [UnboundReceiver<'_>; RQ],
+    ) {
+        let bus = bus.write(Self {
+            receivers: array::from_fn(|_| OnceCell::new()),
+            transmitters: array::from_fn(|_| OnceCell::new()),
+            tx_queue: MpMcQueue::new(),
+            tx: todo!(),
+            rx: todo!(),
+        });
+        (
+            bus,
+            array::from_fn(|i| UnboundTransmitter {
+                bus,
+                inner: &bus.transmitters[i],
+            }),
+            array::from_fn(|i| UnboundReceiver {
+                bus,
+                inner: &bus.receivers[i],
+            }),
+        )
+    }
+}
+
+impl<I: Instance, const TQ: usize, const RQ: usize> Bus for BxCanBus<I, TQ, RQ> {
+    fn transmit(&self, id: Id, value: CanDataFormat) -> Result<(), BusError> {
+        self.tx_queue.enqueue(encode_frame(id, Some(value)));
+        self.distribute_data(id, value);
+        //TODO: trigger CAN_TX interrupt
+        self.handle_tx_interrupt();
+        Ok(())
+    }
+
+    fn request(&self, id: Id) -> Result<(), BusError> {
+        self.tx_queue.enqueue(encode_frame(id, None));
+        self.distribute_remote(id);
+        //TODO: trigger CAN_TX interrupt
+        self.handle_tx_interrupt();
+        Ok(())
+    }
+
+    fn distribute_data(&self, id: Id, value: CanDataFormat) {
+        for inner in self
+            .receivers
+            .iter()
+            .filter_map(|x| x.get())
+            .filter(|x| x.id == id)
+        {
+            critical_section::with(|cs| {
+                inner.queue.borrow(cs).borrow_mut().push_front(value);
+                if let Some(waker) = inner.waker.borrow(cs).take() {
+                    waker.wake()
+                }
+            });
+        }
+    }
+
+    fn distribute_remote(&self, id: Id) {
+        for inner in self
+            .transmitters
+            .iter()
+            .filter_map(|x| x.get())
+            .filter(|x| x.id == id)
+        {
+            critical_section::with(|cs| {
+                inner.remote_received.borrow(cs).set(true);
+                if let Some(waker) = inner.waker.borrow(cs).take() {
+                    waker.wake();
+                }
+            });
+        }
+    }
+}
+
+impl<I: Instance, const TQ: usize, const RQ: usize> BxCanBus<I, TQ, RQ> {
+    pub fn handle_tx_interrupt(&self) -> Result<(), BxCanBusError> {
+        let tx = &self.tx_queue;
+        while let Some(frame) = tx.dequeue() {
+            match self.tx.transmit(&frame) {
+                Ok(status) => match status.dequeued_frame() {
+                    None => {
+                        defmt::debug!("Transmitting CAN frame to {}.", frame.id());
+                    }
+                    Some(old_frame) => {
+                        defmt::debug!(
+                            "Transmitting CAN frame to {} by displacing other to {}, requeing it.",
+                            frame.id(),
+                            old_frame.id()
+                        );
+                        tx.enqueue(old_frame.clone())
+                            .map_err(|_| BxCanBusError::TxQueueFull)?;
+                    }
+                },
+                Err(nb::Error::WouldBlock) => {
+                    defmt::debug!(
+                        "Couldn't trasmit CAN frame to {}, requeing frame.",
+                        frame.id()
+                    );
+                    tx.enqueue(frame).map_err(|_| BxCanBusError::TxQueueFull)?;
+                }
+                Err(_) => unreachable!(),
+            }
+        }
+        Ok(())
+    }
+    pub fn handle_rx_interrupt<I: Instance>(
+        &self,
+        can_rx: &mut Rx0<I>,
+    ) -> Result<(), BxCanBusError> {
+        loop {
+            match can_rx.receive() {
+                Ok(frame) => {
+                    let (channel_id, data) = decode_frame(&frame);
+                    if let Some(data) = data {
+                        self.distribute_data(channel_id, data);
+                    } else {
+                        self.distribute_remote(channel_id);
+                    }
+
+                    /*
+                    if let Some(data) = data {
+                        bus.publish_local(&channel_id, data);
+                    } else if let Some(state) = bus.get(channel_id) {
+                        defmt::debug!("responding to remote frame");
+                        self.tx_queue
+                            .enqueue(encode_frame(channel_id, Some(state)))
+                            .map_err(|_| BxCanBusError::TxQueueFull)?;
+
+                        //TODO on publish
+                    }
+                    */
+                }
+                Err(nb::Error::WouldBlock) => break,
+                Err(nb::Error::Other(_)) => break,
+            }
+        }
+
+        Ok(())
+    }
+}
+
+fn decode_frame(frame: &bxcan::Frame) -> (Id, Option<CanDataFormat>) {
+    let id = match frame.id() {
+        bxcan::Id::Standard(x) => Id::Standard(unsafe { StandardId::new_unchecked(x.as_raw()) }),
+        bxcan::Id::Extended(x) => Id::Extended(unsafe { ExtendedId::new_unchecked(x.as_raw()) }),
+    };
+    if let Some(data) = frame.data() {
+        (id, Some(CanDataFormat::new(data)))
+    } else {
+        (id, None)
+    }
+}
+
+fn encode_frame(id: Id, data: Option<CanDataFormat>) -> bxcan::Frame {
+    let id = match id {
+        Id::Standard(x) => {
+            bxcan::Id::Standard(unsafe { bxcan::StandardId::new_unchecked(x.as_raw()) })
+        }
+        Id::Extended(x) => {
+            bxcan::Id::Extended(unsafe { bxcan::ExtendedId::new_unchecked(x.as_raw()) })
+        }
+    };
+    if let Some(data) = data {
+        bxcan::Frame::new_data(id, bxcan::Data::new(data.data()).expect("valid can data"))
+    } else {
+        bxcan::Frame::new_remote(id, 8)
+    }
+}

canome/src/can.rs

@@ -1,102 +1,421 @@
-use core::{fmt::Debug, marker::ConstParamTy};
+use core::borrow::{Borrow, BorrowMut};
-
+use core::fmt::Debug;
-use crate::{bus::BusBehaviour, BusBackend, BusDataFormat};
+use core::mem::MaybeUninit;
-use bxcan::{ExtendedId, Id, Instance, Rx0, StandardId, Tx};
+use core::ops::{Deref, DerefMut};
 use defmt::Format;
-use heapless::mpmc::MpMcQueue;
+use heapless::Vec;
 
-pub struct BxCanBus<const TX_CAP: usize> {
+use crate::spmc::{Channel, ChannelClient, Receive, Receiver, ReceiverRef};
-    tx_queue: MpMcQueue<(<Self as BusBackend>::ID, Option<<Self as BusBackend>::Data>), TX_CAP>,
+
-    on_publish: &'static (dyn Fn(&Self) + Send + Sync),
+#[derive(Clone, Debug)]
+pub struct CanData(pub Vec<u8, 8>);
+#[derive(Clone, Copy, PartialEq, Eq, Format, Debug)]
+pub enum CanId {
+    Standard(CanStandardId),
+    Extended(CanExtendedId),
+}
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Format)]
+pub struct CanStandardId(u16);
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Format)]
+pub struct CanExtendedId(u32);
+
+#[derive(Clone, Debug, Format)]
+pub enum CanFrame {
+    Data(CanDataFrame),
+    Remote(CanRemoteFrame),
 }
 
-impl<const TX_CAP: usize> Debug for BxCanBus<TX_CAP> {
+#[derive(Clone, Debug, Format)]
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+pub struct CanDataFrame(pub CanId, pub CanData);
-        f.debug_struct("BxCanBus").finish()
+#[derive(Clone, Debug, Format)]
+pub struct CanRemoteFrame(pub CanId);
+
+impl Format for CanData {
+    fn format(&self, fmt: defmt::Formatter) {
+        defmt::write!(fmt, "CanData({})", self.0.as_slice())
     }
 }
 
-#[derive(PartialEq, Eq, ConstParamTy, Debug, Clone, Copy)]
+impl CanStandardId {
-pub enum BxCanId {
+    pub const fn new(value: u16) -> Self {
-    Standard(u16),
+        assert!(value < (1 << 11));
-    Extended(u32),
+        Self(value)
+    }
 }
-
+impl CanExtendedId {
-#[derive(Debug)]
+    pub const fn new(value: u32) -> Self {
-pub enum BxCanBusError {
+        assert!(value < (1 << 29));
-    /// An object couldn't be added to the TX queue of [`BxCanBus`] because it is full.
+        Self(value)
-    TxQueueFull,
-}
-
-impl<const TX_CAP: usize> BusBackend for BxCanBus<TX_CAP> {
-    type ID = BxCanId;
-
-    type Data = CanDataFormat;
-
-    type Error = BxCanBusError;
-
-    fn publish(&self, id: Self::ID, data: Option<Self::Data>) -> Result<(), Self::Error> {
-        self.tx_queue
-            .enqueue((id, data))
-            .map_err(|_| Self::Error::TxQueueFull)?;
-
-        (self.on_publish)(self);
-
-        Ok(())
     }
 }
 
-impl<const TX_CAP: usize> BxCanBus<TX_CAP> {
+impl CanDataFrame {
-    pub const fn new_with_hook(on_publish: &'static (dyn Fn(&Self) + Send + Sync)) -> Self {
+    pub fn id(&self) -> CanId {
+        self.0
+    }
+}
+
+impl CanRemoteFrame {
+    pub fn id(&self) -> CanId {
+        self.0
+    }
+}
+
+impl CanFrame {
+    pub fn id(&self) -> CanId {
+        match *self {
+            Self::Data(CanDataFrame(id, _)) => id,
+            Self::Remote(CanRemoteFrame(id)) => id,
+        }
+    }
+}
+
+impl CanData {
+    pub fn new(data: &[u8]) -> Self {
+        Self(Vec::from_slice(data).unwrap())
+    }
+    pub fn data(&self) -> &[u8] {
+        self.0.as_slice()
+    }
+}
+
+pub trait CanDriver {
+    type Error;
+
+    fn handle<'driver: 'client, 'client, I: CanClientInner<'client, 'driver>>(
+        &'driver self,
+        unbound: &'client mut UnboundCanHandle<'driver, I>,
+        builder: I::InitData,
+    ) -> CanHandleRef<'client, 'driver, I>;
+
+    fn handle_tx_interrupt(&self) -> Result<(), Self::Error>;
+    fn handle_rx_interrupt(&self) -> Result<(), Self::Error>;
+}
+
+trait CanDriverInternal {
+    fn send(&self, value: CanFrame);
+    fn channel(&self) -> &Channel<CanFrame>;
+}
+
+pub struct CanHandleRef<'client, 'driver, I: CanClientInner<'client, 'driver>>(
+    ReceiverRef<'driver, 'client, CanFrame, CanClient<'driver, I>>,
+);
+
+pub struct UnboundCanHandle<'driver, I>(MaybeUninit<CanClient<'driver, I>>);
+
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> Default
+    for UnboundCanHandle<'driver, I>
+{
+    fn default() -> Self {
+        Self(MaybeUninit::uninit())
+    }
+}
+
+pub struct CanHandle<'client, 'driver, I>(&'client CanClient<'driver, I>);
+
+struct CanClient<'driver, I> {
+    driver: &'driver dyn CanDriverInternal,
+    inner: I,
+    client: Option<ChannelClient<CanFrame>>,
+}
+
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> Receive<CanFrame>
+    for CanClient<'driver, I>
+{
+    fn receive(&self, value: &CanFrame) {
+        self.inner.handle_frame(value.clone())
+    }
+}
+
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> Receiver<'driver, CanFrame>
+    for CanClient<'driver, I>
+{
+    fn channel(&self) -> &crate::spmc::Channel<CanFrame> {
+        self.driver.channel()
+    }
+    fn channel_client(&self) -> &ChannelClient<CanFrame> {
+        self.client.as_ref().unwrap()
+    }
+}
+
+pub trait CanClientInner<'client, 'driver> {
+    type InitData;
+    fn new(init_data: Self::InitData, handle: CanHandle<'client, 'driver, Self>) -> Self
+    where
+        Self: Sized;
+    fn handle_frame(&self, frame: CanFrame);
+}
+
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> Borrow<I>
+    for CanHandleRef<'client, 'driver, I>
+{
+    fn borrow(&self) -> &I {
+        &self.0.as_ref().inner
+    }
+}
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> BorrowMut<I>
+    for CanHandleRef<'client, 'driver, I>
+{
+    fn borrow_mut(&mut self) -> &mut I {
+        let x: &mut CanClient<'driver, I> = self.0.borrow_mut();
+        &mut x.inner
+    }
+}
+
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> Deref
+    for CanHandleRef<'client, 'driver, I>
+{
+    type Target = I;
+    fn deref(&self) -> &Self::Target {
+        &self.0.as_ref().inner
+    }
+}
+
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> DerefMut
+    for CanHandleRef<'client, 'driver, I>
+{
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        let x: &mut CanClient<'driver, I> = self.0.borrow_mut();
+        &mut x.inner
+    }
+}
+
+impl<'client, 'driver, I: CanClientInner<'client, 'driver>> CanHandle<'client, 'driver, I> {
+    pub fn send(&self, frame: CanFrame) {
+        self.0.driver.send(frame)
+    }
+}
+
+pub mod basic_client {
+    use super::{CanClientInner, CanFrame, CanHandle};
+    use core::cell::RefCell;
+    use core::future::{poll_fn, Future};
+    use core::task::{Poll, Waker};
+    use critical_section::Mutex;
+    use heapless::Deque;
+
+    pub enum Error {
+        Overflowed,
+    }
+
+    pub struct BasicCanClient<'client, 'driver: 'client, const N: usize> {
+        handle: CanHandle<'client, 'driver, Self>,
+        inner: Mutex<RefCell<BasicCanClientInner<N>>>,
+    }
+
+    struct BasicCanClientInner<const N: usize> {
+        queue: Deque<CanFrame, N>,
+        overflowed: bool,
+        waker: Option<Waker>,
+    }
+
+    impl<'client, 'driver: 'client, const N: usize> CanClientInner<'client, 'driver>
+        for BasicCanClient<'client, 'driver, N>
+    {
+        type InitData = ();
+
+        fn new(_init_data: Self::InitData, handle: CanHandle<'client, 'driver, Self>) -> Self
+        where
+            Self: Sized,
+        {
             Self {
-            tx_queue: MpMcQueue::new(),
+                handle,
-            on_publish,
+                inner: Mutex::new(RefCell::new(BasicCanClientInner {
+                    queue: Deque::new(),
+                    overflowed: false,
+                    waker: None,
+                })),
             }
         }
 
-    pub fn handle_tx_interrupt<I: Instance>(
+        fn handle_frame(&self, frame: CanFrame) {
-        &self,
+            critical_section::with(|cs| {
-        can_tx: &mut Tx<I>,
+                let mut inner = self.inner.borrow_ref_mut(cs);
-    ) -> Result<(), BxCanBusError> {
+                if inner.queue.is_full() {
-        let rx = &self.tx_queue;
+                    inner.queue.pop_back();
+                    inner.overflowed = true;
+                }
+                let Ok(_) = inner.queue.push_front(frame) else {
+                    unreachable!("queue always has at least one free slot")
+                };
+                if let Some(waker) = inner.waker.take() {
+                    waker.wake();
+                }
+            })
+        }
+    }
+    impl<'client, 'driver: 'client, const N: usize> BasicCanClient<'client, 'driver, N> {
+        pub fn recv(&mut self) -> impl Future<Output = Result<CanFrame, Error>> + '_ {
+            poll_fn(|cx| {
+                critical_section::with(|cs| {
+                    let mut inner = self.inner.borrow_ref_mut(cs);
 
-        while let Some((channel_id, data)) = rx.dequeue() {
+                    let waker = cx.waker();
-            let frame = encode_frame(channel_id, data);
+                    if !inner
-            match can_tx.transmit(&frame) {
+                        .waker
-                Ok(status) => match status.dequeued_frame().map(decode_frame) {
+                        .as_ref()
-                    None => {}
+                        .map(|x| x.will_wake(waker))
-                    Some((channel_id, data)) => rx
+                        .unwrap_or_default()
-                        .enqueue((channel_id, data))
+                    {
-                        .map_err(|_| BxCanBusError::TxQueueFull)?,
+                        let mut waker = Some(waker.clone());
+                        core::mem::swap(&mut waker, &mut inner.waker);
+                        if let Some(waker) = waker {
+                            waker.wake();
+                        }
+                    }
+
+                    if inner.overflowed {
+                        inner.overflowed = false;
+                        Poll::Ready(Err(Error::Overflowed))
+                    } else {
+                        match inner.queue.pop_back() {
+                            Some(x) => Poll::Ready(Ok(x)),
+                            None => Poll::Pending,
+                        }
+                    }
+                })
+            })
+        }
+        pub fn try_recv(&mut self) -> Result<Option<CanFrame>, Error> {
+            critical_section::with(|cs| {
+                let mut inner = self.inner.borrow_ref_mut(cs);
+
+                if inner.overflowed {
+                    inner.overflowed = false;
+                    Err(Error::Overflowed)
+                } else {
+                    Ok(inner.queue.pop_back())
+                }
+            })
+        }
+        pub fn send(&mut self, frame: CanFrame) {
+            self.handle.send(frame)
+        }
+    }
+}
+
+pub mod bxcan {
+    use bxcan::{Can, Instance};
+    use critical_section::Mutex;
+    use heapless::{Deque, Vec};
+
+    use crate::{
+        can::CanDriver,
+        spmc::{Channel, ChannelClient},
+    };
+    use core::cell::RefCell;
+
+    use super::{
+        CanClient, CanData, CanDataFrame, CanDriverInternal, CanExtendedId, CanFrame, CanHandle,
+        CanHandleRef, CanId, CanRemoteFrame, CanStandardId,
+    };
+    pub enum Error {
+        TxQueueFull,
+    }
+    pub struct BxCanDriver<I: Instance, const TXN: usize> {
+        clients: Channel<CanFrame>,
+        inner: Mutex<RefCell<BxCanDriverInner<I, TXN>>>,
+    }
+    struct BxCanDriverInner<I: Instance, const TXN: usize> {
+        tx_queue: Deque<CanFrame, TXN>,
+        can: Can<I>,
+    }
+
+    impl<IN: Instance, const TXN: usize> BxCanDriver<IN, TXN> {
+        pub fn new(can: Can<IN>) -> Self {
+            Self {
+                clients: Channel::default(),
+                inner: Mutex::new(RefCell::new(BxCanDriverInner {
+                    can,
+                    tx_queue: Deque::new(),
+                })),
+            }
+        }
+    }
+
+    impl<IN: Instance, const TXN: usize> CanDriverInternal for BxCanDriver<IN, TXN> {
+        fn channel(&self) -> &Channel<CanFrame> {
+            &self.clients
+        }
+        fn send(&self, value: CanFrame) {
+            if critical_section::with(|cs| {
+                //TODO: error handling
+                let mut inner = self.inner.borrow_ref_mut(cs);
+                let was_empty = inner.tx_queue.is_empty();
+                self.clients.distribute(&value);
+                inner.tx_queue.push_front(value);
+                was_empty
+            }) {
+                self.handle_tx_interrupt();
+            }
+        }
+    }
+
+    impl<IN: Instance, const TXN: usize> CanDriver for BxCanDriver<IN, TXN> {
+        type Error = Error;
+
+        fn handle<'driver: 'client, 'client, I: super::CanClientInner<'client, 'driver>>(
+            &'driver self,
+            unbound: &'client mut super::UnboundCanHandle<'driver, I>,
+            builder: I::InitData,
+        ) -> super::CanHandleRef<'client, 'driver, I> {
+            let handle = unbound.0.write(CanClient {
+                driver: self,
+                inner: I::new(builder, CanHandle(unsafe { &*(unbound.0.as_ptr()) })),
+                client: None,
+            });
+
+            handle.client = Some(ChannelClient::new(&*handle));
+
+            CanHandleRef(self.clients.register(handle))
+        }
+
+        fn handle_tx_interrupt(&self) -> Result<(), Error> {
+            critical_section::with(|cs| {
+                let mut inner = self.inner.borrow_ref_mut(cs);
+                inner.can.clear_tx_interrupt();
+                while let Some(frame) = inner.tx_queue.pop_back() {
+                    match inner.can.transmit(&frame.clone().into()) {
+                        Ok(status) => match status.dequeued_frame() {
+                            None => {
+                                defmt::debug!("Transmitting CAN frame to {}.", frame.id());
+                            }
+                            Some(old_frame) => {
+                                defmt::debug!(
+                            "Transmitting CAN frame to {} by displacing other to {}, requeing it.",
+                            frame.id(),
+                            CanId::from(old_frame.id())
+                        );
+                                inner
+                                    .tx_queue
+                                    .push_front(old_frame.clone().into())
+                                    .map_err(|_| Error::TxQueueFull)?;
+                            }
                         },
                         Err(nb::Error::WouldBlock) => {
-                    rx.enqueue((channel_id, data))
+                            defmt::debug!(
-                        .map_err(|_| BxCanBusError::TxQueueFull)?;
+                                "Couldn't trasmit CAN frame to {}, requeing frame.",
-                    break;
+                                frame.id()
+                            );
+                            inner
+                                .tx_queue
+                                .push_front(frame)
+                                .map_err(|_| Error::TxQueueFull)?;
                         }
                         Err(_) => unreachable!(),
                     }
                 }
                 Ok(())
+            })
         }
-    pub fn handle_rx_interrupt<I: Instance>(
+        fn handle_rx_interrupt(&self) -> Result<(), Error> {
-        &self,
+            critical_section::with(|cs| {
-        can_rx: &mut Rx0<I>,
+                let mut inner = self.inner.borrow_ref_mut(cs);
-        bus: impl BusBehaviour<Self>,
-    ) -> Result<(), BxCanBusError> {
                 loop {
-            match can_rx.receive() {
+                    match inner.can.receive() {
                         Ok(frame) => {
-                    let (channel_id, data) = decode_frame(&frame);
+                            let frame = frame.into();
-                    if let Some(data) = data {
+                            self.clients.distribute(&frame)
-                        bus.publish_local(&channel_id, data);
-                    } else if let Some(state) = bus.get(channel_id) {
-                        self.tx_queue
-                            .enqueue((channel_id, Some(state)))
-                            .map_err(|_| BxCanBusError::TxQueueFull)?;
-
-                        (self.on_publish)(self);
-                    }
                         }
                         Err(nb::Error::WouldBlock) => break,
                         Err(nb::Error::Other(_)) => break,
@@ -104,55 +423,52 @@ impl<const TX_CAP: usize> BxCanBus<TX_CAP> {
                 }
 
                 Ok(())
-    }
+            })
-}
-
-#[derive(Clone, Copy, Format, Debug)]
-pub struct CanDataFormat {
-    length: u8,
-    data: [u8; 8],
-}
-
-impl CanDataFormat {
-    pub fn new(data: &[u8]) -> Self {
-        assert!(data.len() <= 8);
-
-        let mut padded = [0_u8; 8];
-        padded[0..data.len()].copy_from_slice(data);
-
-        Self {
-            length: data.len() as u8,
-            data: padded,
         }
     }
 
-    pub fn data(&self) -> &[u8] {
+    impl From<CanFrame> for bxcan::Frame {
-        &self.data[..self.length as usize]
+        fn from(value: CanFrame) -> bxcan::Frame {
+            match value {
+                CanFrame::Data(CanDataFrame(id, data)) => {
+                    bxcan::Frame::new_data(id, bxcan::Data::new(&data.0).unwrap())
                 }
-}
+                CanFrame::Remote(CanRemoteFrame(id)) => bxcan::Frame::new_remote(id, 8),
-
+            }
-impl BusDataFormat for CanDataFormat {}
+        }
-
+    }
-fn decode_frame(frame: &bxcan::Frame) -> (BxCanId, Option<CanDataFormat>) {
+    impl From<bxcan::Frame> for CanFrame {
-    let id = match frame.id() {
+        fn from(value: bxcan::Frame) -> CanFrame {
-        Id::Standard(id) => BxCanId::Standard(id.as_raw()),
+            if let Some(data) = value.data() {
-        Id::Extended(id) => BxCanId::Extended(id.as_raw()),
+                CanFrame::Data(CanDataFrame(
-    };
+                    value.id().into(),
-    if let Some(data) = frame.data() {
+                    CanData(Vec::from_slice(data).unwrap()),
-        (id, Some(CanDataFormat::new(data)))
+                ))
             } else {
-        (id, None)
+                CanFrame::Remote(CanRemoteFrame(value.id().into()))
+            }
+        }
     }
-}
 
-fn encode_frame(id: BxCanId, data: Option<CanDataFormat>) -> bxcan::Frame {
+    impl From<CanId> for bxcan::Id {
-    let id = match id {
+        fn from(value: CanId) -> bxcan::Id {
-        BxCanId::Standard(id) => Id::Standard(StandardId::new(id).unwrap()),
+            match value {
-        BxCanId::Extended(id) => Id::Extended(ExtendedId::new(id).unwrap()),
+                CanId::Standard(CanStandardId(id)) => {
-    };
+                    bxcan::Id::Standard(unsafe { bxcan::StandardId::new_unchecked(id) })
-    if let Some(data) = data {
+                }
-        bxcan::Frame::new_data(id, bxcan::Data::new(data.data()).expect("valid can data"))
+                CanId::Extended(CanExtendedId(id)) => {
-    } else {
+                    bxcan::Id::Extended(unsafe { bxcan::ExtendedId::new_unchecked(id) })
-        bxcan::Frame::new_remote(id, 8)
+                }
+            }
+        }
+    }
+
+    impl From<bxcan::Id> for CanId {
+        fn from(value: bxcan::Id) -> CanId {
+            match value {
+                bxcan::Id::Standard(id) => CanId::Standard(CanStandardId(id.as_raw())),
+                bxcan::Id::Extended(id) => CanId::Extended(CanExtendedId(id.as_raw())),
+            }
+        }
     }
 }

canome/src/canome.rs

@@ -0,0 +1,242 @@
+use critical_section::Mutex;
+use defmt::info;
+use heapless::Deque;
+
+use crate::{
+    can::{CanClientInner, CanData, CanFrame, CanHandle, CanId, CanRemoteFrame},
+    Decode, Encode,
+};
+use core::cell::RefCell;
+use core::future::{poll_fn, Future};
+use core::task::{Poll, Waker};
+
+pub enum Error {
+    Overflowed,
+}
+
+pub trait CanomeChannel {
+    const ID: CanId;
+    type Data: Encode<CanData> + Decode<CanData>;
+}
+
+pub struct CanomeEventClient<'client, 'driver: 'client, C: CanomeChannel, const N: usize> {
+    handle: CanHandle<'client, 'driver, Self>,
+    inner: Mutex<RefCell<CanomeEventClientInner<C, N>>>,
+}
+
+struct CanomeEventClientInner<C: CanomeChannel, const N: usize> {
+    queue: Deque<C::Data, N>,
+    overflowed: bool,
+    waker: Option<Waker>,
+}
+
+impl<'client, 'driver: 'client, C: CanomeChannel, const N: usize> CanClientInner<'client, 'driver>
+    for CanomeEventClient<'client, 'driver, C, N>
+{
+    type InitData = ();
+
+    fn new(_init_data: Self::InitData, handle: CanHandle<'client, 'driver, Self>) -> Self
+    where
+        Self: Sized,
+    {
+        Self {
+            handle,
+            inner: Mutex::new(RefCell::new(CanomeEventClientInner {
+                queue: Deque::new(),
+                overflowed: false,
+                waker: None,
+            })),
+        }
+    }
+
+    fn handle_frame(&self, frame: CanFrame) {
+        if let CanFrame::Data(frame) = frame {
+            if frame.id() == C::ID {
+                if let Ok(data) = C::Data::decode(frame.1) {
+                    critical_section::with(|cs| {
+                        let mut inner = self.inner.borrow_ref_mut(cs);
+                        if inner.queue.is_full() {
+                            inner.queue.pop_back();
+                            inner.overflowed = true;
+                        }
+                        inner.queue.push_front(data);
+
+                        if let Some(waker) = inner.waker.take() {
+                            waker.wake();
+                        }
+                    })
+                } else {
+                    todo!()
+                }
+            }
+        }
+    }
+}
+
+impl<'client, 'driver: 'client, C: CanomeChannel, const N: usize>
+    CanomeEventClient<'client, 'driver, C, N>
+{
+    pub fn recv(&mut self) -> impl Future<Output = Result<C::Data, Error>> + '_ {
+        poll_fn(|cx| {
+            critical_section::with(|cs| {
+                let mut inner = self.inner.borrow_ref_mut(cs);
+
+                let waker = cx.waker();
+                if !inner
+                    .waker
+                    .as_ref()
+                    .map(|x| x.will_wake(waker))
+                    .unwrap_or_default()
+                {
+                    let mut waker = Some(waker.clone());
+                    core::mem::swap(&mut waker, &mut inner.waker);
+                    if let Some(waker) = waker {
+                        waker.wake();
+                    }
+                }
+
+                if inner.overflowed {
+                    inner.overflowed = false;
+                    Poll::Ready(Err(Error::Overflowed))
+                } else {
+                    match inner.queue.pop_back() {
+                        Some(x) => Poll::Ready(Ok(x)),
+                        None => Poll::Pending,
+                    }
+                }
+            })
+        })
+    }
+    pub fn try_recv(&mut self) -> Result<Option<C::Data>, Error> {
+        critical_section::with(|cs| {
+            let mut inner = self.inner.borrow_ref_mut(cs);
+
+            if inner.overflowed {
+                inner.overflowed = false;
+                Err(Error::Overflowed)
+            } else {
+                Ok(inner.queue.pop_back())
+            }
+        })
+    }
+    pub fn send(&mut self, data: C::Data) {
+        self.handle.send(CanFrame::Data(crate::can::CanDataFrame(
+            C::ID,
+            data.encode(),
+        )))
+    }
+}
+
+pub struct CanomeStateClient<'client, 'driver: 'client, C: CanomeChannel> {
+    handle: CanHandle<'client, 'driver, Self>,
+    inner: Mutex<RefCell<CanomeStateClientInner<C>>>,
+}
+
+struct CanomeStateClientInner<C: CanomeChannel> {
+    last: C::Data,
+    counter: u64,
+    waker: Option<Waker>,
+}
+
+impl<'client, 'driver: 'client, C: CanomeChannel> CanClientInner<'client, 'driver>
+    for CanomeStateClient<'client, 'driver, C>
+where
+    C::Data: Default,
+{
+    type InitData = ();
+
+    fn new(_init_data: Self::InitData, handle: CanHandle<'client, 'driver, Self>) -> Self
+    where
+        Self: Sized,
+    {
+        Self {
+            handle,
+            inner: Mutex::new(RefCell::new(CanomeStateClientInner {
+                last: C::Data::default(),
+                counter: 0,
+                waker: None,
+            })),
+        }
+    }
+
+    fn handle_frame(&self, frame: CanFrame) {
+        if let CanFrame::Data(frame) = frame {
+            if frame.id() == C::ID {
+                if let Ok(data) = C::Data::decode(frame.1) {
+                    critical_section::with(|cs| {
+                        let mut inner = self.inner.borrow_ref_mut(cs);
+
+                        inner.last = data;
+                        inner.counter += 1;
+
+                        if let Some(waker) = inner.waker.take() {
+                            waker.wake();
+                        }
+                    })
+                } else {
+                    todo!()
+                }
+            }
+        }
+    }
+}
+
+impl<'client, 'driver: 'client, C: CanomeChannel> CanomeStateClient<'client, 'driver, C>
+where
+    C::Data: Clone + Default,
+{
+    pub fn next(&mut self) -> impl Future<Output = C::Data> + '_ {
+        let this: &'_ Self = self;
+        let counter_start: u64 = critical_section::with(|cs| self.inner.borrow_ref(cs).counter);
+        poll_fn(move |cx| {
+            critical_section::with(|cs| {
+                let mut inner = this.inner.borrow_ref_mut(cs);
+
+                let waker = cx.waker();
+                if !inner
+                    .waker
+                    .as_ref()
+                    .map(|x| x.will_wake(waker))
+                    .unwrap_or_default()
+                {
+                    let mut waker = Some(waker.clone());
+                    core::mem::swap(&mut waker, &mut inner.waker);
+                    if let Some(waker) = waker {
+                        waker.wake();
+                    }
+                }
+
+                if inner.counter > counter_start {
+                    Poll::Ready(inner.last.clone())
+                } else {
+                    Poll::Pending
+                }
+            })
+        })
+    }
+    pub fn get(&mut self) -> C::Data {
+        critical_section::with(|cs| {
+            let inner = self.inner.borrow_ref(cs);
+            inner.last.clone()
+        })
+    }
+    pub fn counter(&self) -> u64 {
+        critical_section::with(|cs| {
+            let inner = self.inner.borrow_ref(cs);
+            inner.counter
+        })
+    }
+    pub fn send(&mut self, data: C::Data) {
+        self.handle.send(CanFrame::Data(crate::can::CanDataFrame(
+            C::ID,
+            data.encode(),
+        )))
+    }
+    pub fn request(&mut self) {
+        self.handle.send(CanFrame::Remote(CanRemoteFrame(C::ID)));
+    }
+    pub fn request_and_wait(&mut self) -> impl Future<Output = C::Data> + '_ {
+        self.handle.send(CanFrame::Remote(CanRemoteFrame(C::ID)));
+        self.next()
+    }
+}

canome/src/contact.rs

@@ -16,24 +16,23 @@ impl ContactState {
     }
 }
 
-#[cfg(feature = "can")]
 mod can {
-    use crate::{can::CanDataFormat, Decode, Encode};
+    use crate::{can::CanData, Decode, Encode};
 
     use super::ContactState;
 
-    impl Encode<CanDataFormat> for ContactState {
+    impl Encode<CanData> for ContactState {
-        fn encode(self) -> CanDataFormat {
+        fn encode(self) -> CanData {
             let data = match self {
                 Self::Open => 0,
                 Self::Closed => 1,
             };
-            CanDataFormat::new(&[data])
+            CanData::new(&[data])
         }
     }
 
-    impl Decode<CanDataFormat> for ContactState {
+    impl Decode<CanData> for ContactState {
-        fn decode(value: CanDataFormat) -> Result<Self, CanDataFormat>
+        fn decode(value: CanData) -> Result<Self, CanData>
         where
             Self: Sized,
         {

canome/src/cover.rs

@@ -15,22 +15,40 @@ impl CoverState {
     }
 }
 
-#[cfg(feature = "can")]
+#[derive(Default, Debug, Format, Clone, Copy, PartialEq, Eq)]
+pub struct CoverControl {
+    pub sequence_number: u8,
+    pub command: CoverCommand,
+}
+
+#[derive(Default, Debug, Format, Clone, Copy, PartialEq, Eq)]
+pub enum CoverCommand {
+    #[default]
+    None,
+    Stop,
+    Open,
+    Close,
+    TiltMin,
+    TiltMax,
+    Position(u16),
+    Tilt(u16),
+}
+
 mod can {
-    use crate::{can::CanDataFormat, Decode, Encode};
+    use crate::{can::CanData, Decode, Encode};
 
-    use super::CoverState;
+    use super::{CoverCommand, CoverControl, CoverState};
 
-    impl Encode<CanDataFormat> for CoverState {
+    impl Encode<CanData> for CoverState {
-        fn encode(self) -> CanDataFormat {
+        fn encode(self) -> CanData {
             let hue = self.tilt.to_be_bytes();
             let saturation = self.position.to_be_bytes();
-            CanDataFormat::new(&[hue[0], hue[1], saturation[0], saturation[1]])
+            CanData::new(&[hue[0], hue[1], saturation[0], saturation[1]])
         }
     }
 
-    impl Decode<CanDataFormat> for CoverState {
+    impl Decode<CanData> for CoverState {
-        fn decode(value: CanDataFormat) -> Result<Self, CanDataFormat>
+        fn decode(value: CanData) -> Result<Self, CanData>
         where
             Self: Sized,
         {
@@ -48,4 +66,58 @@ mod can {
             })
         }
     }
+
+    impl Encode<CanData> for CoverControl {
+        fn encode(self) -> CanData {
+            let seq = self.sequence_number;
+            let (kind, data): (u8, &[u8]) = match self.command {
+                CoverCommand::None => (0, &[]),
+                CoverCommand::Stop => (1, &[]),
+                CoverCommand::Open => (2, &[]),
+                CoverCommand::Close => (3, &[]),
+                CoverCommand::TiltMin => (4, &[]),
+                CoverCommand::TiltMax => (5, &[]),
+                CoverCommand::Position(val) => (6, &val.to_be_bytes()),
+                CoverCommand::Tilt(val) => (7, &val.to_be_bytes()),
+            };
+            let mut payload = [seq, kind, 0, 0, 0, 0, 0, 0];
+            payload[2..].copy_from_slice(&data);
+
+            CanData::new(&payload[0..(2 + data.len())])
+        }
+    }
+
+    impl Decode<CanData> for CoverControl {
+        fn decode(value: CanData) -> Result<Self, CanData>
+        where
+            Self: Sized,
+        {
+            use CoverCommand as C;
+            let data = value.data();
+            if data.len() < 2 {
+                return Err(value);
+            }
+
+            let sequence_number = data[0];
+            let command = data[1];
+            let data = &data[2..];
+
+            let command = match command {
+                0 => C::None,
+                1 => C::Stop,
+                2 => C::Open,
+                3 => C::Close,
+                4 => C::TiltMin,
+                5 => C::TiltMax,
+                6 if data.len() == 2 => C::Position(u16::from_be_bytes([data[0], data[1]])),
+                7 if data.len() == 2 => C::Tilt(u16::from_be_bytes([data[0], data[1]])),
+                _ => return Err(value),
+            };
+
+            Ok(Self {
+                sequence_number,
+                command,
+            })
+        }
+    }
 }

canome/src/lib.rs

@@ -1,37 +1,73 @@
 #![no_std]
 #![feature(adt_const_params)]
+#![feature(associated_const_equality)]
 use core::fmt::Debug;
 
-pub mod bus;
+use defmt::Format;
-#[cfg(feature = "can")]
+
+//pub mod bus;
+//#[cfg(feature = "bxcan")]
+//pub mod bxcan;
 pub mod can;
+pub mod canome;
 pub mod contact;
 pub mod cover;
 pub mod light;
 pub mod power;
+#[cfg(feature = "socketcan")]
+pub mod socketcan;
+pub mod spmc;
 pub mod state;
 #[cfg(feature = "stm32")]
 pub mod stm32;
 pub mod time;
 
-pub trait Channel<B: BusBackend> {
+pub use embedded_can::{ExtendedId, Id, StandardId};
-    const ID: B::ID;
-    type State: Encode<B::Data> + Decode<B::Data>;
-}
 
-pub trait Encode<F: BusDataFormat> {
+/*
+pub trait Channel {
+    const ID: embedded_can::Id;
+    type Message: Encode<CanDataFormat> + Decode<CanDataFormat>;
+}
+*/
+
+pub trait Encode<F> {
     fn encode(self) -> F;
 }
-pub trait Decode<F: BusDataFormat> {
+pub trait Decode<F> {
     fn decode(value: F) -> Result<Self, F>
     where
         Self: Sized;
 }
 
-pub trait BusDataFormat: Debug + Clone {}
+/*
-pub trait BusBackend {
+pub trait BusBackend: Send + Sync {
-    type ID: Debug + Clone;
-    type Data: BusDataFormat;
     type Error;
-    fn publish(&self, id: Self::ID, data: Option<Self::Data>) -> Result<(), Self::Error>;
+    fn publish(&self, id: embedded_can::Id, data: Option<CanDataFormat>)
+        -> Result<(), Self::Error>;
 }
+
+#[derive(Clone, Copy, Format, Debug)]
+pub struct CanDataFormat {
+    length: usize,
+    data: [u8; 8],
+}
+
+impl CanDataFormat {
+    pub fn new(data: &[u8]) -> Self {
+        assert!(data.len() <= 8);
+
+        let mut padded = [0_u8; 8];
+        padded[0..data.len()].copy_from_slice(data);
+
+        Self {
+            length: data.len(),
+            data: padded,
+        }
+    }
+
+    pub fn data(&self) -> &[u8] {
+        &self.data[..self.length]
+    }
+}
+*/

canome/src/power.rs

@@ -5,25 +5,24 @@ pub struct PowermeterState {
     pub total: u32,
     pub current: u32,
 }
-#[cfg(feature = "can")]
 mod can {
-    use crate::{can::CanDataFormat, Decode, Encode};
+    use crate::{can::CanData, Decode, Encode};
 
     use super::PowermeterState;
 
-    impl Encode<CanDataFormat> for PowermeterState {
+    impl Encode<CanData> for PowermeterState {
-        fn encode(self) -> CanDataFormat {
+        fn encode(self) -> CanData {
             let total = self.total.to_be_bytes();
             let current = self.current.to_be_bytes();
-            CanDataFormat::new(&[
+            CanData::new(&[
                 total[0], total[1], total[2], total[3], current[0], current[1], current[2],
                 current[3],
             ])
         }
     }
 
-    impl Decode<CanDataFormat> for PowermeterState {
+    impl Decode<CanData> for PowermeterState {
-        fn decode(value: CanDataFormat) -> Result<Self, CanDataFormat>
+        fn decode(value: CanData) -> Result<Self, CanData>
         where
             Self: Sized,
         {

canome/src/socketcan.rs

@@ -0,0 +1,147 @@
+use core::fmt::Debug;
+
+use crate::{BusBackend, CanDataFormat};
+use defmt::Format;
+use embedded_can::{ExtendedId, Frame, Id, StandardId};
+use heapless::mpmc::MpMcQueue;
+use socketcan::{CanDataFrame, CanFrame, CanRemoteFrame};
+
+pub struct SocketCanBus<const TX_CAP: usize> {
+    pub tx_queue: MpMcQueue<socketcan::CanFrame, TX_CAP>,
+    on_publish: &'static (dyn Fn(&Self) + Send + Sync),
+}
+
+impl<const TX_CAP: usize> Debug for SocketCanBus<TX_CAP> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.debug_struct("SocketCanBus").finish()
+    }
+}
+
+#[derive(Debug)]
+pub enum SocketCanBusError {
+    /// An object couldn't be added to the TX queue of [`BxCanBus`] because it is full.
+    TxQueueFull,
+}
+
+impl<const TX_CAP: usize> BusBackend for SocketCanBus<TX_CAP> {
+    type Error = SocketCanBusError;
+
+    fn publish(&self, id: Id, data: Option<CanDataFormat>) -> Result<(), Self::Error> {
+        self.tx_queue
+            .enqueue(encode_frame(id, data))
+            .map_err(|_| Self::Error::TxQueueFull)?;
+
+        (self.on_publish)(self);
+
+        Ok(())
+    }
+}
+
+impl<const TX_CAP: usize> SocketCanBus<TX_CAP> {
+    pub const fn new_with_hook(on_publish: &'static (dyn Fn(&Self) + Send + Sync)) -> Self {
+        Self {
+            tx_queue: MpMcQueue::new(),
+            on_publish,
+        }
+    }
+}
+
+impl<const TX_CAP: usize> SocketCanBus<TX_CAP> {}
+
+/*
+impl<const TX_CAP: usize> SocketCanBus<TX_CAP> {
+    pub fn handle_tx_interrupt<I: Instance>(
+        &self,
+        can_tx: &mut Tx<I>,
+    ) -> Result<(), SocketCanBusError> {
+        let rx = &self.tx_queue;
+        while let Some(frame) = rx.dequeue() {
+            match can_tx.transmit(&frame) {
+                Ok(status) => match status.dequeued_frame() {
+                    None => {
+                        defmt::debug!("Transmitting CAN frame to {}.", frame.id());
+                    }
+                    Some(old_frame) => {
+                        defmt::debug!(
+                            "Transmitting CAN frame to {} by displacing other to {}, requeing it.",
+                            frame.id(),
+                            old_frame.id()
+                        );
+                        rx.enqueue(old_frame.clone())
+                            .map_err(|_| SocketCanBusError::TxQueueFull)?;
+                    }
+                },
+                Err(nb::Error::WouldBlock) => {
+                    defmt::debug!(
+                        "Couldn't trasmit CAN frame to {}, requeing frame.",
+                        frame.id()
+                    );
+                    rx.enqueue(frame)
+                        .map_err(|_| SocketCanBusError::TxQueueFull)?;
+                }
+                Err(_) => unreachable!(),
+            }
+        }
+        Ok(())
+    }
+    pub fn handle_rx_interrupt<I: Instance>(
+        &self,
+        can_rx: &mut Rx0<I>,
+        bus: impl BusBehaviour<Self>,
+    ) -> Result<(), SocketCanBusError> {
+        loop {
+            match can_rx.receive() {
+                Ok(frame) => {
+                    let (channel_id, data) = decode_frame(&frame);
+                    if let Some(data) = data {
+                        bus.publish_local(&channel_id, data);
+                    } else if let Some(state) = bus.get(channel_id) {
+                        defmt::debug!("responding to remote frame");
+                        self.tx_queue
+                            .enqueue(encode_frame(channel_id, Some(state)))
+                            .map_err(|_| SocketCanBusError::TxQueueFull)?;
+
+                        (self.on_publish)(self);
+                    }
+                }
+                Err(nb::Error::WouldBlock) => break,
+                Err(nb::Error::Other(_)) => break,
+            }
+        }
+
+        Ok(())
+    }
+}
+*/
+
+pub fn decode_frame(frame: &socketcan::CanFrame) -> (Id, Option<CanDataFormat>) {
+    let id = match frame.id() {
+        socketcan::Id::Standard(x) => {
+            Id::Standard(unsafe { StandardId::new_unchecked(x.as_raw()) })
+        }
+        socketcan::Id::Extended(x) => {
+            Id::Extended(unsafe { ExtendedId::new_unchecked(x.as_raw()) })
+        }
+    };
+    match frame {
+        CanFrame::Data(data) => (id, Some(CanDataFormat::new(data.data()))),
+        CanFrame::Remote(_) => (id, None),
+        CanFrame::Error(_) => unimplemented!(),
+    }
+}
+
+pub fn encode_frame(id: Id, data: Option<CanDataFormat>) -> CanFrame {
+    let id = match id {
+        Id::Standard(x) => {
+            socketcan::Id::Standard(unsafe { socketcan::StandardId::new_unchecked(x.as_raw()) })
+        }
+        Id::Extended(x) => {
+            socketcan::Id::Extended(unsafe { socketcan::ExtendedId::new_unchecked(x.as_raw()) })
+        }
+    };
+    if let Some(data) = data {
+        CanFrame::Data(CanDataFrame::new(id, data.data()).unwrap())
+    } else {
+        CanFrame::Remote(CanRemoteFrame::new_remote(id, 8).unwrap())
+    }
+}

canome/src/spmc.rs

@@ -0,0 +1,418 @@
+use core::borrow::{Borrow, BorrowMut};
+use core::cell::RefCell;
+use core::marker::PhantomData;
+use core::ops::{Deref, DerefMut};
+
+use core::ptr::NonNull;
+
+use critical_section::Mutex;
+
+#[derive(PartialEq)]
+pub enum Error {
+    Overflowed,
+}
+
+pub type CanData = [u8; 8];
+pub type CanId = u32;
+
+pub struct Channel<T>(Mutex<RefCell<Option<ClientList<T>>>>);
+
+unsafe impl<T> Send for Channel<T> {}
+
+struct ClientList<T> {
+    head: NonNull<ChannelClient<T>>,
+    tail: NonNull<ChannelClient<T>>,
+}
+
+pub struct ChannelClient<T> {
+    receiver: NonNull<dyn Receive<T>>,
+    nav: Mutex<RefCell<ChannelClientNav<T>>>,
+}
+
+struct ChannelClientNav<T> {
+    next: Option<NonNull<ChannelClient<T>>>,
+    prev: Option<NonNull<ChannelClient<T>>>,
+}
+
+pub trait Receiver<'channel, T>: Receive<T> {
+    fn channel_client(&self) -> &ChannelClient<T>;
+    fn channel(&self) -> &Channel<T>;
+}
+pub trait Receive<T> {
+    fn receive(&self, value: &T);
+}
+
+pub struct ReceiverRef<'channel, 'receiver, T, R: Receiver<'channel, T>>(
+    &'receiver mut R,
+    PhantomData<&'channel Channel<T>>,
+);
+
+impl<T> ChannelClient<T> {
+    pub fn new<'channel, R: Receiver<'channel, T>>(receiver: &R) -> Self {
+        Self {
+            receiver: NonNull::new(receiver as *const dyn Receive<T> as *mut _).unwrap(),
+            nav: Mutex::new(RefCell::new(ChannelClientNav {
+                prev: None,
+                next: None,
+            })),
+        }
+    }
+}
+
+impl<T> Channel<T> {
+    pub fn register<'channel, 'receiver, R: Receiver<'channel, T>>(
+        &'channel self,
+        receiver: &'receiver mut R,
+    ) -> ReceiverRef<'channel, 'receiver, T, R>
+    where
+        'channel: 'receiver,
+    {
+        let client_ref = receiver.channel_client();
+        let client_ptr = NonNull::new(client_ref as *const _ as *mut _).unwrap();
+
+        critical_section::with(|cs| {
+            let mut client_list = self.0.borrow(cs).borrow_mut();
+            if let Some(client_list) = &mut *client_list {
+                let old_head = client_list.head;
+                client_ref.nav.borrow(cs).borrow_mut().next = Some(old_head);
+
+                let old_head = unsafe { old_head.as_ref() };
+                old_head.nav.borrow(cs).borrow_mut().prev = Some(client_ptr);
+                client_list.head = client_ptr;
+            } else {
+                *client_list = Some(ClientList {
+                    head: client_ptr,
+                    tail: client_ptr,
+                });
+            }
+        });
+
+        ReceiverRef(receiver, PhantomData)
+    }
+    pub fn distribute(&self, value: &T) {
+        critical_section::with(|cs| {
+            let list = self.0.borrow(cs).borrow();
+            if let Some(list) = &*list {
+                let mut next = Some(list.head);
+                while let Some(current) = next {
+                    let current = unsafe { current.as_ref() };
+
+                    let receiver = unsafe { current.receiver.as_ref() };
+                    receiver.receive(value);
+
+                    next = current.nav.borrow(cs).borrow().next;
+                }
+            }
+        })
+    }
+}
+
+impl<'channel, 'receiver, T, R: Receiver<'channel, T>> Deref
+    for ReceiverRef<'channel, 'receiver, T, R>
+{
+    type Target = R;
+    fn deref(&self) -> &Self::Target {
+        self.0
+    }
+}
+
+impl<'channel, 'receiver, T, R: Receiver<'channel, T>> DerefMut
+    for ReceiverRef<'channel, 'receiver, T, R>
+{
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        self.0
+    }
+}
+
+impl<'channel, 'receiver, T, R: Receiver<'channel, T>> AsRef<R>
+    for ReceiverRef<'channel, 'receiver, T, R>
+{
+    fn as_ref(&self) -> &R {
+        self.0
+    }
+}
+
+impl<'channel, 'receiver, T, R: Receiver<'channel, T>> Borrow<R>
+    for ReceiverRef<'channel, 'receiver, T, R>
+{
+    fn borrow(&self) -> &R {
+        self.0
+    }
+}
+
+impl<'channel, 'receiver, T, R: Receiver<'channel, T>> BorrowMut<R>
+    for ReceiverRef<'channel, 'receiver, T, R>
+{
+    fn borrow_mut(&mut self) -> &mut R {
+        self.0
+    }
+}
+
+impl<T> Default for Channel<T> {
+    fn default() -> Self {
+        Self(Mutex::new(RefCell::new(None)))
+    }
+}
+
+impl<'channel, 'receiver, T, R: Receiver<'channel, T>> Drop
+    for ReceiverRef<'channel, 'receiver, T, R>
+{
+    fn drop(&mut self) {
+        critical_section::with(|cs| {
+            let receiver = &mut self.0;
+            let channel = receiver.channel();
+            let own_nav = receiver.channel_client().nav.borrow(cs).borrow_mut();
+
+            match (own_nav.prev, own_nav.next) {
+                (None, None) => {
+                    // this item is the last one in the list, we need to tear down the entire list
+                    let mut can_driver_list = channel.0.borrow(cs).borrow_mut();
+                    *can_driver_list = None;
+                }
+                (None, Some(next)) => {
+                    // this item is the first in the list, we need to update the head ptr and the
+                    // prev ptr of next
+                    let mut can_driver_list = channel.0.borrow(cs).borrow_mut();
+                    let can_driver_list = can_driver_list.as_mut().unwrap();
+                    can_driver_list.head = next;
+
+                    let next = unsafe { next.as_ref() };
+                    next.nav.borrow(cs).borrow_mut().prev = None;
+                }
+                (Some(prev), None) => {
+                    // this item is the last one in the list, we need to update the tail ptr and
+                    // the next ptr of prev
+
+                    let mut can_driver_list = channel.0.borrow(cs).borrow_mut();
+                    let can_driver_list = can_driver_list.as_mut().unwrap();
+                    can_driver_list.tail = prev;
+
+                    let prev = unsafe { prev.as_ref() };
+                    prev.nav.borrow(cs).borrow_mut().next = None;
+                }
+                (Some(prev), Some(next)) => {
+                    // this item is in the middle of the list, we need to update the next ptr of
+                    // prev and the prev ptr of next
+
+                    {
+                        let next = unsafe { next.as_ref() };
+                        next.nav.borrow(cs).borrow_mut().prev = Some(prev);
+                    }
+                    {
+                        let prev = unsafe { prev.as_ref() };
+                        prev.nav.borrow(cs).borrow_mut().next = Some(next);
+                    }
+                }
+            }
+        });
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::{Channel, ChannelClient, ChannelClientNav, Error, Receive, Receiver};
+    use core::cell::RefCell;
+    use core::future::{poll_fn, Future};
+    use core::mem::MaybeUninit;
+    use core::ptr::NonNull;
+    use core::task::{Poll, Waker};
+    use critical_section::Mutex;
+    use heapless::Deque;
+
+    pub struct UnboundReceiver<'channel, T, const N: usize>(
+        MaybeUninit<ChannelReceiver<'channel, T, N>>,
+    );
+    impl<'channel, T, const N: usize> AsMut<MaybeUninit<ChannelReceiver<'channel, T, N>>>
+        for UnboundReceiver<'channel, T, N>
+    {
+        fn as_mut(&mut self) -> &mut MaybeUninit<ChannelReceiver<'channel, T, N>> {
+            &mut self.0
+        }
+    }
+    impl<'channel, T, const N: usize> Default for UnboundReceiver<'channel, T, N> {
+        fn default() -> Self {
+            Self(MaybeUninit::uninit())
+        }
+    }
+    impl<'candriver, T, const N: usize> ChannelReceiver<'candriver, T, N> {
+        pub fn recv(&mut self) -> impl Future<Output = Result<T, Error>> + '_ {
+            poll_fn(|cx| {
+                match critical_section::with(|cs| {
+                    let mut inner = self.inner.borrow(cs).borrow_mut();
+
+                    // register waker
+                    let waker = cx.waker();
+                    if !inner
+                        .waker
+                        .as_ref()
+                        .map(|x| x.will_wake(waker))
+                        .unwrap_or_default()
+                    {
+                        let mut waker = Some(waker.clone());
+                        core::mem::swap(&mut inner.waker, &mut waker);
+                        if let Some(waker) = waker {
+                            waker.wake();
+                        }
+                    }
+
+                    if inner.overflowed {
+                        inner.overflowed = false;
+                        Err(Error::Overflowed)
+                    } else {
+                        Ok(inner.queue.pop_back())
+                    }
+                }) {
+                    Err(x) => Poll::Ready(Err(x)),
+                    Ok(Some(x)) => Poll::Ready(Ok(x)),
+                    Ok(None) => Poll::Pending,
+                }
+            })
+        }
+        pub fn try_recv(&mut self) -> Result<Option<T>, Error> {
+            critical_section::with(|cs| {
+                let mut inner = self.inner.borrow(cs).borrow_mut();
+
+                if inner.overflowed {
+                    inner.overflowed = false;
+                    Err(Error::Overflowed)
+                } else {
+                    Ok(inner.queue.pop_back())
+                }
+            })
+        }
+    }
+
+    pub struct ChannelReceiver<'channel, T, const N: usize> {
+        channel: &'channel Channel<T>,
+        client: Option<ChannelClient<T>>,
+        inner: Mutex<RefCell<ChannelReceiverInner<T, N>>>,
+    }
+    impl<'channel, T: Clone, const N: usize> ChannelReceiver<'channel, T, N> {
+        fn init<'a>(
+            channel: &'channel Channel<T>,
+            memory: &'a mut UnboundReceiver<'channel, T, N>,
+        ) -> &'a mut Self
+        where
+            Self: Sized,
+        {
+            let receiver = memory.0.write(ChannelReceiver {
+                channel,
+                client: None,
+                inner: Mutex::new(RefCell::new(ChannelReceiverInner {
+                    queue: Deque::new(),
+                    overflowed: false,
+                    waker: None,
+                })),
+            });
+
+            receiver.client = Some(ChannelClient {
+                receiver: NonNull::new(receiver as *mut _ as *const dyn Receive<T> as *mut _)
+                    .unwrap(),
+                nav: Mutex::new(RefCell::new(ChannelClientNav {
+                    next: None,
+                    prev: None,
+                })),
+            });
+
+            receiver
+        }
+    }
+    impl<'channel, T: Clone, const N: usize> Receiver<'channel, T> for ChannelReceiver<'channel, T, N> {
+        fn channel(&self) -> &Channel<T> {
+            self.channel
+        }
+        fn channel_client(&self) -> &ChannelClient<T> {
+            self.client.as_ref().unwrap()
+        }
+    }
+    impl<'candriver, T: Clone, const N: usize> Receive<T> for ChannelReceiver<'candriver, T, N> {
+        fn receive(&self, value: &T) {
+            critical_section::with(|cs| {
+                let mut inner = self.inner.borrow(cs).borrow_mut();
+                if inner.queue.is_full() {
+                    inner.queue.pop_back();
+                    inner.overflowed = true;
+                }
+                let Ok(_) = inner.queue.push_front(value.clone()) else {
+                    unreachable!()
+                };
+            })
+        }
+    }
+
+    struct ChannelReceiverInner<T, const N: usize> {
+        queue: Deque<T, N>,
+        overflowed: bool,
+        waker: Option<Waker>,
+    }
+
+    #[test]
+    pub fn basic() {
+        let can_driver = Channel::default();
+
+        let mut recv1 = UnboundReceiver::default();
+        let recv1 = ChannelReceiver::init(&can_driver, &mut recv1);
+        let mut recv1 = can_driver.register::<ChannelReceiver<'_, u32, 2>>(recv1);
+
+        //test overflowing behaviour
+        assert!(recv1.try_recv() == Ok(None));
+        can_driver.distribute(&0);
+
+        assert!(recv1.try_recv() == Ok(Some(0)));
+        assert!(recv1.try_recv() == Ok(None));
+    }
+
+    #[test]
+    pub fn overflow() {
+        let can_driver = Channel::default();
+
+        let mut recv1 = UnboundReceiver::default();
+        let recv1 = ChannelReceiver::init(&can_driver, &mut recv1);
+        let mut recv1 = can_driver.register::<ChannelReceiver<'_, u32, 10>>(recv1);
+
+        //test overflowing behaviour
+        assert!(recv1.try_recv() == Ok(None));
+        for i in 0..11 {
+            can_driver.distribute(&i);
+        }
+        assert!(recv1.try_recv() == Err(Error::Overflowed));
+        for i in 1..11 {
+            assert!(recv1.try_recv() == Ok(Some(i)));
+        }
+        assert!(recv1.try_recv() == Ok(None));
+    }
+    #[test]
+    pub fn multi_receiver() {
+        let can_driver = Channel::default();
+
+        let mut recv1 = UnboundReceiver::default();
+        let recv1 = ChannelReceiver::init(&can_driver, &mut recv1);
+        let mut recv1 = can_driver.register::<ChannelReceiver<'_, u32, 2>>(recv1);
+
+        let mut recv2 = UnboundReceiver::default();
+        let recv2 = ChannelReceiver::init(&can_driver, &mut recv2);
+        let mut recv2 = can_driver.register::<ChannelReceiver<'_, u32, 2>>(recv2);
+
+        {
+            can_driver.distribute(&0);
+            assert!(recv1.try_recv() == Ok(Some(0)));
+            assert!(recv2.try_recv() == Ok(Some(0)));
+        }
+
+        {
+            can_driver.distribute(&1);
+            can_driver.distribute(&2);
+            assert!(recv1.try_recv() == Ok(Some(1)));
+            assert!(recv1.try_recv() == Ok(Some(2)));
+            assert!(recv2.try_recv() == Ok(Some(1)));
+            assert!(recv2.try_recv() == Ok(Some(2)));
+        }
+
+        drop(recv1);
+
+        {
+            can_driver.distribute(&3);
+            assert!(recv2.try_recv() == Ok(Some(3)));
+        }
+    }
+}

canome/src/state.rs

@@ -6,24 +6,23 @@ pub enum ThreeWaySwitchState {
     B,
 }
 
-#[cfg(feature = "can")]
 mod can {
-    use crate::{can::CanDataFormat, Decode, Encode};
+    use crate::{can::CanData, Decode, Encode};
 
     use super::ThreeWaySwitchState;
 
-    impl Encode<CanDataFormat> for ThreeWaySwitchState {
+    impl Encode<CanData> for ThreeWaySwitchState {
-        fn encode(self) -> CanDataFormat {
+        fn encode(self) -> CanData {
             let desc = match self {
                 Self::Off => 0,
                 Self::A => 1,
                 Self::B => 2,
             };
-            CanDataFormat::new(&[desc])
+            CanData::new(&[desc])
         }
     }
-    impl Decode<CanDataFormat> for ThreeWaySwitchState {
+    impl Decode<CanData> for ThreeWaySwitchState {
-        fn decode(value: CanDataFormat) -> Result<Self, CanDataFormat>
+        fn decode(value: CanData) -> Result<Self, CanData>
         where
             Self: Sized,
         {

canome/src/stm32.rs

@@ -1,6 +1,10 @@
 use core::ops::{Deref, DerefMut};
 
-use crate::{bus::BusRx, state::ThreeWaySwitchState, BusBackend, Channel};
+use crate::{
+    can::{CanHandle, CanHandleRef},
+    canome::{CanomeChannel, CanomeEventClient, CanomeStateClient},
+    state::ThreeWaySwitchState,
+};
 use rtic_monotonics::{
     systick::{
         fugit::{Duration, Instant},
@@ -37,26 +41,26 @@ impl<const AP: char, const AN: u8, const BP: char, const BN: u8> ThreeWaySwitch<
     }
 }
 
-pub struct ChannelDerivative<'a, C: Channel<B>, R: BusRx<C, B>, B: BusBackend> {
+pub struct ChannelDerivative<'handle, 'driver, C: CanomeChannel, const N: usize> {
-    channel: &'a R,
+    channel: CanHandleRef<'handle, 'driver, CanomeEventClient<'handle, 'driver, C, N>>,
-    last: C::State,
+    last: C::Data,
     updated: Instant<u32, 1, 1000>,
 }
-impl<'a, C, R, B> ChannelDerivative<'a, C, R, B>
+impl<'handle, 'driver, C, const N: usize> ChannelDerivative<'handle, 'driver, C, N>
 where
-    C: Channel<B>,
+    C: CanomeChannel,
-    C::State: Default + PartialEq + Clone,
+    C::Data: Default + PartialEq + Clone,
-    R: BusRx<C, B>,
-    B: BusBackend,
 {
-    pub fn new(channel: &'a R) -> Self {
+    pub fn new(
+        channel: CanHandleRef<'handle, 'driver, CanomeEventClient<'handle, 'driver, C, N>>,
+    ) -> Self {
         Self {
             channel,
-            last: C::State::default(),
+            last: C::Data::default(),
             updated: Systick::now(),
         }
     }
-    pub fn update(&mut self, new: C::State) -> Option<(C::State, Duration<u32, 1, 1000>)> {
+    pub fn update(&mut self, new: C::Data) -> Option<(C::Data, Duration<u32, 1, 1000>)> {
         if new != self.last {
             self.last = new.clone();
             let now = Systick::now();
@@ -67,10 +71,13 @@ where
             None
         }
     }
-    pub async fn next(&mut self) -> (C::State, Duration<u32, 1, 1000>) {
+    pub async fn recv(
+        &mut self,
+    ) -> Result<(C::Data, Duration<u32, 1, 1000>), crate::canome::Error> {
         loop {
-            if let Some(value) = self.update(self.channel.next().await) {
+            let new = self.channel.recv().await?;
-                return value;
+            if let Some(value) = self.update(new) {
+                return Ok(value);
             }
         }
     }

canome/src/time.rs

@@ -5,21 +5,20 @@ pub struct Timestamp {
     millis_since_epoch: i64,
 }
 
-#[cfg(feature = "can")]
 mod can {
-    use crate::{can::CanDataFormat, Decode, Encode};
+    use crate::{can::CanData, Decode, Encode};
 
     use super::Timestamp;
 
-    impl Encode<CanDataFormat> for Timestamp {
+    impl Encode<CanData> for Timestamp {
-        fn encode(self) -> CanDataFormat {
+        fn encode(self) -> CanData {
             let timestamp = self.millis_since_epoch.to_be_bytes();
-            CanDataFormat::new(&timestamp)
+            CanData::new(&timestamp)
         }
     }
 
-    impl Decode<CanDataFormat> for Timestamp {
+    impl Decode<CanData> for Timestamp {
-        fn decode(value: CanDataFormat) -> Result<Self, CanDataFormat>
+        fn decode(value: CanData) -> Result<Self, CanData>
         where
             Self: Sized,
         {