topic Re: status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback in Kinetis Microcontrollers

status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback

stdcerr — Wed, 11 Nov 2020 18:27:57 GMT

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.

Re: status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback

Omar_Anguiano — Tue, 17 Nov 2020 19:45:08 GMT

Hello

Can you provide the part number you are working with?

I'm awaiting for your reply.

Re: status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback

stdcerr — Tue, 17 Nov 2020 19:55:17 GMT

Definitely can, I'm working with a MK64FN1M0VLL12

Re: status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback

Omar_Anguiano — Tue, 17 Nov 2020 20:40:19 GMT

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

Re: status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback

stdcerr — Wed, 18 Nov 2020 00:13:49 GMT

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.

Re: status is set to kStatus_FLEXCAN_UnHandled in flexcan_callback

stdcerr — Wed, 18 Nov 2020 00:42:45 GMT

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.