STM32F103ZET6 CAN Bus is not working

[pkumar1883]

Posted on May 06, 2015 at 14:52

Dear I am trying to run the CAN bus of STM2F103ZET6. If I am not wrong it is on PB11 and PB12 pins.

My code is as in attached file. I run code and check the waveform on logic analyzer and CRO both but nothing is happening.

[Tesla DeLorean]

Posted on May 06, 2015 at 17:07

PA11 and PA12, I hope.

And you have it connected to what exactly? A transceiver and another CAN bus device?

[Tesla DeLorean]

Posted on May 06, 2015 at 17:08

PA11 and PA12, I hope.

And you have it connected to what exactly? A transceiver and another CAN bus device?

[pkumar1883]

Posted on May 07, 2015 at 10:26

Dear Clive1,

Thank you for reply. yes PA11 and PA12 right. I have connected these to CAN transceiver(SN65HVD230). Schematic is shown below- ________________ Attachments : IMG_20150507_134755.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0pW&d=%2Fa%2F0X0000000bel%2FIW7qZgw9r4MukgPsmyROqTovXmSXU5faVKr1rwCDxkY&asPdf=false

[jpeacock]

Posted on May 07, 2015 at 14:14

What does the ESR register show?  Does the other node (you need two to test CAN, a single node always fails) also show an error?  If the other node is okay then the transceiver is working.

If you see a high TEC and a bus off (BOFF) status that means you aren't connected to an active bus with another node.   Jack Peacock

[pkumar1883]

Posted on May 08, 2015 at 10:37

Dear Jack Peacock,

I have connected the CAN transceiver at both ends but still no waveform at CRO.

[pkumar1883]

Posted on May 08, 2015 at 14:58

Hello Guys,

Thank you all for your support. Finally it is working now. I made 2 changes... 1. In code I did this  

CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;

  CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;   CAN_InitStructure.CAN_BS1 = CAN_BS1_2tq;   CAN_InitStructure.CAN_BS2 = CAN_BS2_3tq;   CAN_InitStructure.CAN_Prescaler = 48; (for 125kbps speed) 2. In hardware added 120E resistance at both ends.

[pkumar1883]

Posted on May 08, 2015 at 17:08

Dear Clive,

Please tell me the settings in the following code for 500kbps.

CAN_InitStructure.CAN_TTCM = DISABLE;

  CAN_InitStructure.CAN_ABOM = DISABLE;   CAN_InitStructure.CAN_AWUM = DISABLE;   CAN_InitStructure.CAN_NART = DISABLE;   CAN_InitStructure.CAN_RFLM = DISABLE;   CAN_InitStructure.CAN_TXFP = DISABLE;   CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;   CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;   CAN_InitStructure.CAN_BS1 = CAN_BS1_2tq;   CAN_InitStructure.CAN_BS2 = CAN_BS2_3tq;   CAN_InitStructure.CAN_Prescaler = 48;   CAN_Init(CAN1, &CAN_InitStructure);  /* CAN filter init */   CAN_FilterInitStructure.CAN_FilterNumber=0;   CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;   CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;   CAN_FilterInitStructure.CAN_FilterIdHigh=0x0000;   CAN_FilterInitStructure.CAN_FilterIdLow=0x0000;   CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0x0000;   CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000;   CAN_FilterInitStructure.CAN_FilterFIFOAssignment=0;   CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;   CAN_FilterInit(&CAN_FilterInitStructure);