RP2040_MCP251863_Driver

A driver for the RP2040 to interface with the MCP251863 CANFD Transceiver + Controller

CAN FD send/receive API

uint8_t payload[8] = {0x01, 0x02, 0x03, 0x04};

can.send_canfd(0x123, payload, 4, true);
can.send_canfd(0x18DAF110, payload, 4, true, true);

CanFdFrame frame = can.read_canfd();
if (frame.valid) {
    // frame.id, frame.data, frame.len, frame.brs, frame.esi, frame.ide, frame.fdf
}

send_canfd() and read_canfd() use the configured TX/RX FIFOs, which default to FIFO 1 and FIFO 2. Use the FIFO-number overloads when a call should target a specific FIFO.

For full control over the transmit object, use send_frame() with CanFdFrame. It supports standard or extended IDs, classical CAN or CAN FD, DLC/length mapping, BRS, ESI, RTR, SID11, and TEF sequence numbers. read_frame() decodes the receive object into the same struct, including filter hit and optional RX timestamp fields.

Default initialization

init() now performs the chip bring-up sequence: reset, oscillator readiness wait, configuration mode, nominal/data bit timing, TDC, FIFO setup, accept-all RX filter, interrupt enables, transceiver normal mode, and CAN FD normal mode.

The built-in defaults assume a 40 MHz CAN clock, 500 kbit/s nominal arbitration rate, 2 Mbit/s CAN FD data rate, TX FIFO 1, RX FIFO 2, and 64-byte payload FIFOs. Use init(config) with InitConfig to override timing, FIFO numbers, FIFO depths, payload sizes, PLL, and TDC settings.

Named timing presets are available for common 40 MHz-clock cases:

config.nominalBitTiming = kBitTiming500K40MHz;
config.dataBitTiming = kBitTiming2M40MHz;

Use getStatus() for controller-wide interrupt, bus error, error counter, bus-off, and SPI CRC status. Use getFIFOStatus(fifo) for FIFO full/empty, RX overflow, TX attempts exhausted, arbitration lost, aborted, and TX error flags.

Minimal validation examples live in examples/canfd_tx_example.cpp and examples/canfd_rx_example.cpp.