topic Re: MSCAN can't transmit in Digital Signal Controllers

MSCAN can't transmit

terrybogard — Fri, 28 May 2021 06:16:45 GMT

I test MSCAN in loopback mode, it wors well. but when loop mode disabled, it can't transmit the frame. Pls give me some advice about code below. Is there any code demo about MSCAN not use loop mode in MC56F82748?Thx.

Sending data frame without interrupt service (polling)

The following example demonstrates sending a data frame with standard ID and extended ID.

OnFreeTxBuffer event is called when a frame is successfully transmitted and returns buffer index (in this case 0), which was send.

Required component setup :

Interrupt service : Disabled
Message buffers : 1, Buffer0 - Buffer type: Transmit
Bit rate : 100kbit/s
Loop mode : no
Enabled in init. code : yes
Methods to enable : SendFrame
Events to enable : OnFreeTxBuffer

Content of ProcessorExpert.c:

volatile bool DataFrameTxFlg;LDD_TDeviceData *MyCANPtr;LDD_TError Error;LDD_CAN_TFrame Frame;uint8_t OutData[4] = {0x00U, 0x01U, 0x02U, 0x03U}; /* Initialization of output data buffer */ void main(void){ . . . MyCANPtr = CAN2_Init(NULL); /* Initialization of CAN2 component */ Frame.MessageID = 0x123U; /* Set Tx ID value - standard */ Frame.FrameType = LDD_CAN_DATA_FRAME; /* Specyfying type of Tx frame - Data frame */ Frame.Length = sizeof(OutData); /* Set number of bytes in data frame - 4B */ Frame.Data = OutData; /* Set pointer to OutData buffer */ DataFrameTxFlg = FALSE; /* Initialization of DataFrameTxFlg */ Error = CAN2_SendFrame(MyCANPtr, 0U, &Frame); /* Sends the data frame over buffer 0 */ while (!DataFrameTxFlg) { /* Wait until data frame is transmitted */ CAN2_Main(MyCANPtr); } . . . Frame.MessageID = (0x123456U | LDD_CAN_MESSAGE_ID_EXT); /* Set Tx ID value - extended */ Frame.FrameType = LDD_CAN_DATA_FRAME; /* Specyfying type of Tx frame - Data frame */ Frame.Length = sizeof(OutData); /* Set number of bytes in data frame - 4B */ Frame.Data = OutData; /* Set pointer to OutData buffer */ DataFrameTxFlg = FALSE; /* Clear DataFrameTxFlg */ Error = CAN2_SendFrame(MyCANPtr, 0U, &Frame); /* Sends the data frame over buffer 0 */ while (!DataFrameTxFlg) { /* Wait until data frame is transmitted */ CAN2_Main(MyCANPtr); } . . . for(;;) {}}

Content of Event.c:

extern volatile bool DataFrameTxFlg;void CAN2_OnFreeTxBuffer(LDD_TUserData *UserDataPtr, LDD_CAN_TMBIndex BufferIdx){ DataFrameTxFlg = TRUE; /* Set DataFrameTxFlg flag */}

Re: MSCAN can't transmit

terrybogard — Fri, 28 May 2021 06:20:21 GMT

volatile bool DataFrameTxFlg;
LDD_TDeviceData *MyCANPtr;
LDD_TError Error;
LDD_CAN_TFrame Frame;
uint8_t OutData[4] = {0x04U, 0x08U, 0x0cU, 0x0fU}; /* Initialization of output data buffer */

void main(void)
{

/*** Processor Expert internal initialization. DON'T REMOVE THIS CODE!!! ***/
PE_low_level_init();
/*** End of Processor Expert internal initialization. ***/

MyCANPtr = CAN1_Init(NULL); /* Initialization of CAN1 component */

Frame.MessageID = 0x123U; /* Set Tx ID value - standard */
Frame.FrameType = LDD_CAN_DATA_FRAME; /* Specyfying type of Tx frame - Data frame */
Frame.Length = sizeof(OutData); /* Set number of bytes in data frame - 4B */
Frame.Data = OutData; /* Set pointer to OutData buffer */
DataFrameTxFlg = FALSE; /* Initialization of DataFrameTxFlg */
Error = CAN1_SendFrame(MyCANPtr, 0U, &Frame); /* Sends the data frame over buffer 0 */
while (!DataFrameTxFlg) { /* Wait until data frame is transmitted */
CAN1_Main(MyCANPtr);
}

Frame.MessageID = (0x123456U | LDD_CAN_MESSAGE_ID_EXT); /* Set Tx ID value - extended */
Frame.FrameType = LDD_CAN_DATA_FRAME; /* Specyfying type of Tx frame - Data frame */
Frame.Length = sizeof(OutData); /* Set number of bytes in data frame - 4B */
Frame.Data = OutData; /* Set pointer to OutData buffer */
DataFrameTxFlg = FALSE; /* Clear DataFrameTxFlg */
Error = CAN1_SendFrame(MyCANPtr, 0U, &Frame); /* Sends the data frame over buffer 0 */
while (!DataFrameTxFlg) { /* Wait until data frame is transmitted */
CAN1_Main(MyCANPtr);
}

for(;;) {}
}

Content of Event.c:

extern volatile bool DataFrameTxFlg;

void CAN2_OnFreeTxBuffer(LDD_TUserData *UserDataPtr, LDD_CAN_TMBIndex BufferIdx)

{ DataFrameTxFlg = TRUE; /* Set DataFrameTxFlg flag */}

Re: MSCAN can't transmit

xiangjun_rong — Mon, 31 May 2021 05:50:58 GMT

Hi,

I have not see the code which configured the mcan pin assignment.

Pls try to use the code:

SIM_PCE1|=0x01; //enable mcan module gated clock

SIM_PCE0|=1<<4; //enable GPIOC gated clock

GPIOC_PER|=3<<11;

//GPIOC11 CANTX SCL0 TXD1
// GPIOC12 CANRX SDA0 RXD1

SIM_GPSCH&=0xFC3F;

Pls have a try

XiangJun Rong

Re: MSCAN can't transmit

terrybogard — Tue, 01 Jun 2021 04:01:16 GMT

thx for Xiangjun's answer, i am sure i have done the pin assignment by processor expert as below.

when i debug, in CANTFLG register, TXE0 = 0 all the time: mean Transmit buffer full (not sent, scheduled).

Re: MSCAN can't transmit

xiangjun_rong — Tue, 01 Jun 2021 07:02:13 GMT

Hi,

Because the CAN transmit node requires acknowledge signal from the CAN receiver, so you have to connect two CAN module via transceiver when you have a test to transfer can message.

XiangJun Rong