how-to/c/openChannels.c

This example shows how to open a channel in CAN and CAN FD mode. See Open Channel for more information.

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#include <canlib.h>
#include <stdio.h>

// Print status message if stat contains an error code
static void check(const char* id, canStatus stat)
{
        if (stat != canOK) {
                char buf[50];
                buf[0] = '\0';
                // Retreive informational text about the status code
                canGetErrorText(stat, buf, sizeof(buf));
                printf("%s: failed, stat=%d (%s)\n", id, (int)stat, buf);
        }
} // check

canHandle open_channel_as_can(int channel_number)
{
        canHandle hnd;
        canStatus stat;

        // open channel in CAN mode
        hnd = canOpenChannel(channel_number, 0);
        if (hnd < 0) {
                check("canOpenChannel", (canStatus)hnd);
                return hnd;
        }
        // set the bus speed to 500 kbit/s
        stat = canSetBusParams(hnd, canBITRATE_500K, 0, 0, 0, 0, 0);
        check("canSetBusParams", stat);
        return hnd;
}

canHandle open_channel_as_canfd(int channel_number)
{
        canHandle hnd;
        canStatus stat;

        // open channel in CAN FD mode
        hnd = canOpenChannel(channel_number, canOPEN_CAN_FD | canOPEN_EXCLUSIVE);
        if (hnd < 0) {
                check("canOpenChannel", (canStatus)hnd);
                return hnd;
        }
        // set the arbitration bitrate to 500 kbit/s, with sampling point to 80%,
        // and data phase bitrate to 1000 kbit/s, with sampling point at 80%
        stat = canSetBusParams(hnd, canFD_BITRATE_500K_80P, 0, 0, 0, 0, 0);
        check("canSetBusParams", stat);
        stat = canSetBusParamsFd(hnd, canFD_BITRATE_1M_80P, 0, 0, 0);
        check("canSetBusParamsFD", stat);

        // return handle to channel
        return hnd;
}