Kettenoeler/Software/src/can.cpp

#ifdef FEATURE_ENABLE_CAN
#include "can.h"

MCP_CAN CAN0(GPIO_CS_CAN);

void Init_CAN()
{

    if (CAN0.begin(MCP_STDEXT, CAN_500KBPS, MCP_16MHZ) != CAN_OK)
        MaintainDTC(DTC_CAN_TRANSCEIVER_FAILED, DTC_CRITICAL, true);

    CAN0.init_Mask(0, 0, 0x07FF0000); // Init first mask...
    CAN0.init_Mask(1, 0, 0x07FF0000); // Init second mask...
    CAN0.init_Filt(0, 0, 0x012D0000); // Init first filter...

    CAN0.setMode(MCP_NORMAL);
}

uint32_t Process_CAN_WheelSpeed()
{
#define FACTOR_RWP_KMH_890ADV 18 // Divider to convert Raw Data to km/h

    can_frame canMsg;
    static uint32_t lastRecTimestamp = 0;
    uint16_t RearWheelSpeed_raw;
    uint32_t milimeters_to_add = 0;

    if (CAN0.readMsgBuf(&canMsg.can_id, &canMsg.can_dlc, canMsg.data) == CAN_OK)
    {
        RearWheelSpeed_raw = (uint16_t)canMsg.data[5] << 8 | canMsg.data[6];
        // raw / FACTOR_RWP_KMH_890ADV -> km/h * 100000 -> cm/h / 3600 -> cm/s
        // raw * 500 -> cm/s
        uint32_t RWP_millimeter_per_second = (((uint32_t)RearWheelSpeed_raw * 1000000) / FACTOR_RWP_KMH_890ADV) / 3600;

        uint32_t timesincelast = millis() - lastRecTimestamp;
        lastRecTimestamp = millis();

        milimeters_to_add = (RWP_millimeter_per_second * timesincelast) / 1000;
    }

    if (lastRecTimestamp != 0)
    {
        MaintainDTC(DTC_NO_CAN_SIGNAL, DTC_CRITICAL, (millis() > lastRecTimestamp + 10000 ? true : false));
    }

    return milimeters_to_add;
}
#endif