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Namespace CANProtocol

Namespace List > CANProtocol

Public Functions

Type Name
bool busOff ()
Return true if the CAN controller is in bus-off state.
void drain ()
Process RX callbacks and batched-ControlPacket deadlines. Call once per loop().
void filterAcceptAll ()
Accept all incoming CAN frames. Use for PanelBridge .
void filterAcceptId (uint32_t canId)
Accept a specific CAN ID. Use for PanelGroup nodes.
void flushBatched (uint32_t canId)
Force a half-full ControlPacketPair batch to send immediately.
HeartbeatPayload makeHeartbeatPayload (uint8_t nodeId, uint16_t rxCount)
Build the standard 8-byte heartbeat payload for the current node.
void onReceive (CanRxCallback cb)
Register a general-purpose RX frame handler.
void onStatusChange (CanStatusCallback cb)
Register a CAN bus status change callback.
void onSyncReq (CanSyncReqCallback cb)
Register a SYNC_REQ handler.
uint8_t rec ()
Return the CAN Receive Error Counter (0-255) from ESR.
void send (uint32_t canId, const uint8_t * data, uint8_t len)
Send a CAN frame.
void sendBatched (uint32_t canId, const ControlPacket & pkt)
Submit one ControlPacket to a CANProtocol-owned ControlPacketPair batch.
void start ()
Start the CAN peripheral and apply registered filters.
void startLoopback ()
Start in silent loopback mode — for bench testing only.
uint8_t tec ()
Return the CAN Transmit Error Counter (0-255) from ESR.
uint32_t txDropCount ()
Return the cumulative TX queue drop count since startup.

Public Functions Documentation

function busOff

Return true if the CAN controller is in bus-off state. 

bool CANProtocol::busOff ()

function drain

Process RX callbacks and batched-ControlPacket deadlines. Call once per loop(). 

void CANProtocol::drain ()

Drains all frames received since the last call: * SYNC_REQ: fires onSyncReq(), not forwarded to onReceive(). * TEST_SEQ: auto-replies with ECHO carrying the same payload, not forwarded. * All other frames: fires onReceive().

Also services sendBatched() deadlines: a half-full ControlPacketPair that has waited two drain() calls is flushed with slot B set to the null sentinel.

function filterAcceptAll

Accept all incoming CAN frames. Use for PanelBridge .

void CANProtocol::filterAcceptAll ()

Configures a pass-all hardware mask filter. Mandatory IDs (CTRL_BCAST, TEST_SEQ, SYNC_REQ) are included but have no effect with pass-all active.

function filterAcceptId

Accept a specific CAN ID. Use for PanelGroup nodes.

void CANProtocol::filterAcceptId (
    uint32_t canId
)

Adds one ID to the hardware filter list. Call multiple times for multiple IDs. CTRL_BCAST (0x010), TEST_SEQ (0x011), and SYNC_REQ (0x012) are always included automatically by start() — do not add them manually.

Parameters:

  • canId 11-bit standard CAN ID to accept.

function flushBatched

Force a half-full ControlPacketPair batch to send immediately. 

void CANProtocol::flushBatched (
    uint32_t canId
)

If the named CAN ID has a pending slot A, sends it with slot B as the null sentinel. No-op if no packet is pending.

Parameters:

  • canId CAN_ID_CTRL_BCAST, canIdEvt(NODE_ID), canIdEvtRel(NODE_ID), or canIdEvtDir(NODE_ID).

function makeHeartbeatPayload

Build the standard 8-byte heartbeat payload for the current node. 

HeartbeatPayload CANProtocol::makeHeartbeatPayload (
    uint8_t nodeId,
    uint16_t rxCount
)

Fills uptime, CAN health flags, and ESR-derived TEC/REC from CANProtocol state.

Parameters:

  • nodeId Node ID (1-63 PanelGroup; 0 reserved for PanelBridge).
  • rxCount Caller-owned receive counter to embed in the payload.

Returns:

Fully populated HeartbeatPayload ready to send as HB_n.

function onReceive

Register a general-purpose RX frame handler. 

void CANProtocol::onReceive (
    CanRxCallback cb
)

Fired by drain() for all frames except SYNC_REQ and TEST_SEQ. Only one handler per node — PanelGroup and PanelBridge each register their own.

Parameters:

  • cb Callback invoked with canId, data pointer, and payload length.

function onStatusChange

Register a CAN bus status change callback. 

void CANProtocol::onStatusChange (
    CanStatusCallback cb
)

Fires immediately with the current status upon registration (STARTING before start() is called), then on each subsequent status transition.

Parameters:

  • cb Callback to invoke with the new CanStatus.

function onSyncReq

Register a SYNC_REQ handler. 

void CANProtocol::onSyncReq (
    CanSyncReqCallback cb
)

Fired by drain() when SYNC_REQ (0x012) is received. PanelGroup registers this to trigger a re-poll of all registered input objects.

Parameters:

  • cb Callback to invoke on SYNC_REQ receipt.

function rec

Return the CAN Receive Error Counter (0-255) from ESR. 

uint8_t CANProtocol::rec ()

function send

Send a CAN frame. 

void CANProtocol::send (
    uint32_t canId,
    const uint8_t * data,
    uint8_t len
)

Sends immediately if a TX mailbox is free; otherwise enqueues in the TX ring buffer (~16 entries), drained automatically via TX-complete interrupt. CTRL_BCAST coalesces stale queued state (newest wins). EVT/control frames retry up to 3 attempts then drop. All drops increment txDropCount().

Parameters:

  • canId 11-bit standard CAN ID.
  • data Pointer to payload bytes.
  • len Payload length in bytes (0-8).

function sendBatched

Submit one ControlPacket to a CANProtocol-owned ControlPacketPair batch. 

void CANProtocol::sendBatched (
    uint32_t canId,
    const ControlPacket & pkt
)

Valid only for CAN_ID_CTRL_BCAST and the batched event frames — canIdEvt(n) (absolute), canIdEvtRel(n) (RotaryEncoder REL), and canIdEvtDir(n) (RotaryEncoder DIR) — each with its own pending slot. Pairs two consecutive packets into one 8-byte frame. If slot B does not arrive within two drain() calls, slot A is sent with slot B set to the null sentinel (controlId == 0x0000).

Parameters:

  • canId CAN_ID_CTRL_BCAST, canIdEvt(NODE_ID), canIdEvtRel(NODE_ID), or canIdEvtDir(NODE_ID).
  • pkt ControlPacket to batch.

function start

Start the CAN peripheral and apply registered filters. 

void CANProtocol::start ()

Must be called after STM32Board::begin() and after all filter and callback registrations. Always adds CTRL_BCAST, TEST_SEQ, and SYNC_REQ to the active filter — mandatory for all nodes, cannot be excluded.

Fires the onStatusChange callback with NORMAL on success.

function startLoopback

Start in silent loopback mode — for bench testing only. 

void CANProtocol::startLoopback ()

Identical to start() but uses CAN_MODE_SILENT_LOOPBACK: frames transmitted by this node are received back internally without going on the physical bus.

Note:

Never call this in production firmware.

function tec

Return the CAN Transmit Error Counter (0-255) from ESR. 

uint8_t CANProtocol::tec ()

function txDropCount

Return the cumulative TX queue drop count since startup. 

uint32_t CANProtocol::txDropCount ()

The documentation for this class was generated from the following file Firmware/Libraries/CANProtocol/CANProtocol.cpp