status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback

[stdcerr]

Hi,

I'm working on a receive only CAN application that reads data from a sensor but am not able to receive anything so far.

The setup

I have a tilt sensor attached to my uC CAN module (PTB18 & PTB19) that continuously sends out frames at 250kbit/s. I have a CAN analyzer connected with which I can see the frames on the bus.

The plan is to use Kinetis to read these frames for further processing.

I planned to retrieve data with FLEXCAN_TransferReceiveNonBlocking but realized that statusis constantly set to kStatus_FLEXCAN_RxBusy even with the sensor disconnected.
A call to FLEXCAN_TransferHandleIRQ(EXAMPLE_CAN, &flexcanHandle); will invoke the callback with status set to kStatus_FLEXCAN_UnHandled.
mbState of the mailbox is set to 1 (kFLEXCAN_StateRxData).
The callback never is invoked with status = kStatus_FLEXCAN_RxIdle

Code:

globals:

#define EXAMPLE_CAN                CAN0
#define EXAMPLE_CAN_CLK_SOURCE     (kFLEXCAN_ClkSrc1)
#define EXAMPLE_CAN_CLK_FREQ       CLOCK_GetFreq(kCLOCK_BusClk)
#define RX_MESSAGE_BUFFER_NUM      (9)
#define DLC                        (8)
#define SET_CAN_QUANTUM            (0)
#define PSEG1                      (3)
#define PSEG2                      (2)
#define PROPSEG                    (1)
#define LOG_INFO                   (void)PRINTF

volatile bool rxComplete = false;
flexcan_frame_t rxFrame;
flexcan_mb_transfer_t rxXfer;
flexcan_handle_t flexcanHandle;

CAN setup:

    FLEXCAN_GetDefaultConfig(&flexcanConfig);

#if defined(EXAMPLE_CAN_CLK_SOURCE)
    flexcanConfig.clksrc=EXAMPLE_CAN_CLK_SOURCE;
#endif

    flexcanConfig.enableListenOnlyMode = true;
    flexcanConfig.baudRate = 250000U;
    //flexcanConfig.enableLoopBack = true;

    FLEXCAN_Init(EXAMPLE_CAN, &flexcanConfig, EXAMPLE_CAN_CLK_FREQ);
    /* Create FlexCAN handle structure and set call back function. */
    FLEXCAN_TransferCreateHandle(EXAMPLE_CAN, &flexcanHandle, flexcan_callback, NULL);

    /* Setup Rx Message Buffer. */
    mbConfig.format = kFLEXCAN_FrameFormatStandard;
    mbConfig.type   = kFLEXCAN_FrameTypeData;
    mbConfig.id     = FLEXCAN_ID_STD(0x10FF53C2);
    FLEXCAN_SetRxMbConfig(EXAMPLE_CAN, RX_MESSAGE_BUFFER_NUM, &mbConfig, true);

    /* Start receive data through Rx Message Buffer. */
    rxXfer.mbIdx = (uint8_t)RX_MESSAGE_BUFFER_NUM;
    rxXfer.frame = &rxFrame;

the callback:

static void flexcan_callback(CAN_Type *base, flexcan_handle_t *handle, status_t status, uint32_t result, void *userData)
{
    switch (status)
    {
        /* Process FlexCAN Rx event. */
        case kStatus_FLEXCAN_RxIdle:
            if (RX_MESSAGE_BUFFER_NUM == result) {
                rxComplete = true;
            }
            LOG_INFO("kStatus_FLEXCAN_RxIdle\r\n");
            break;
        case kStatus_FLEXCAN_UnHandled:
        	LOG_INFO("kStatus_FLEXCAN_UnHandled\r\n");
        	break;
        default:
        	LOG_INFO("in flexcan_cb, status 0x%x(%d)\r\n",status,status);
    }

}

receiving loop:

    while (!rxComplete) {
    	(void)FLEXCAN_TransferReceiveNonBlocking(EXAMPLE_CAN, &flexcanHandle, &rxXfer);
    	FLEXCAN_TransferHandleIRQ(EXAMPLE_CAN, &flexcanHandle);
    }

I also did attach flexcan_test.c that contains the above code.

[Omar_Anguiano]

Hello

Thank you for provide me the part number.

I suggest you to refer to the example flexcan_loopback_transfer disabling the loopback. In the callback for the RX please disable the interruption flag. Also you can do test with a lower baudrate, 125000 was helpful.

Let me know if this is helpful, if you have more questions do not hesitate to ask me.

Best regards,

Omar

[stdcerr]

Hi,

Thank you for the reply.

The flexcan loopback example is where I started from, I experimented with multiple baudrates and all seemed fine until I initialized my pins, removed the loopback and set the baudrate to match the sensor's 250000U. I would be notified through the callback, but status would never be set to kStatus_FLEXCAN_RxIdle but instead status is set to 0x14be and I could not figure out what this is telling me.

[stdcerr]

Okay, I figured out, that 0x14BE stands for "kStatus_FLEXCAN_ErrorStatus" which gets set due to the value Err Status value that comes from FLEXCAN_GetStatusFlags() has the kFLEXCAN_ErrorIntFlag bit set. In the comment it just reads "Error Interrupt Flag" - I need to get this fixed.

[Omar_Anguiano]

Hello

Can you provide the part number you are working with?

I'm awaiting for your reply.

[stdcerr]

Definitely can, I'm working with a MK64FN1M0VLL12