STM32F4 DISCOVERY CAN bus controller problem

keyboqian · ‎2012-07-13

Posted on July 13, 2012 at 15:57

Hi all,

I am trying to get the CAN interface working on the STM32F4DISCOVERY board.

After calling the configuration functions from the peripheral library, when I tried to transmit message with just a oscilloscope connected to the TX and RX pins it does not work. I tried usng CAN_TransmitStatus() to see the status of the mailbox and it returned ''pending''. Then I tracked down the register in the CAN controller, the error flag is up and further more it says ''BIT DOMINANT error''...

I don't know if I need to connect to a transceiver first and hook this board onto a CAN bus before I test it out? Or is it just something wrong with the configuration.

Here is the code I had for the configuration part:

---(I just used GPIOE pin0 to see if the program is running, nothing else)

/* Enable GPIO clock */

RCC_AHB1PeriphClockCmd(CAN_GPIO_CLK|RCC_AHB1Periph_GPIOE, ENABLE);

/* Connect CAN pins to AF9 */

GPIO_PinAFConfig(CAN_GPIO_PORT, CAN_RX_SOURCE, CAN_AF_PORT);

GPIO_PinAFConfig(CAN_GPIO_PORT, CAN_TX_SOURCE, CAN_AF_PORT);

/* Configure CAN RX and TX pins */

GPIO_InitStructure.GPIO_Pin = CAN_RX_PIN | CAN_TX_PIN;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

GPIO_Init(CAN_GPIO_PORT, &GPIO_InitStructure);

//RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);

//configure a pin for debug

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

GPIO_Init(GPIOE, &GPIO_InitStructure);

/* CAN configuration ********************************************************/

/* Enable CAN clock */

RCC_APB1PeriphClockCmd(CAN_CLK, ENABLE);

/* CAN register init */

CAN_DeInit(CANx);

/* CAN cell init */

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 Baudrate = 1 MBps (CAN clocked at 30 MHz) */

CAN_InitStructure.CAN_BS1 = CAN_BS1_6tq;

CAN_InitStructure.CAN_BS2 = CAN_BS2_8tq;

CAN_InitStructure.CAN_Prescaler = 2;

CAN_Init(CANx, &CAN_InitStructure);

/* CAN filter init */

#ifdef USE_CAN1

CAN_FilterInitStructure.CAN_FilterNumber = 0;

#else /* USE_CAN2 */

CAN_FilterInitStructure.CAN_FilterNumber = 14;

#endif /* USE_CAN1 */

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);

/* Transmit Structure preparation */

TxMessage.StdId = 0x321;

TxMessage.ExtId = 0x01;

TxMessage.RTR = CAN_RTR_DATA;

TxMessage.IDE = CAN_ID_STD;

TxMessage.DLC = 1;

/* Enable FIFO 0 message pending Interrupt */

CAN_ITConfig(CANx, CAN_IT_FMP0, ENABLE);

Any help is very appreciated. Thanks!

Keybo

hamed · ‎2014-06-12

Posted on June 12, 2014 at 12:38

I'm so sorry. I did not explain it correctly. I've used the following circuit. Is this true? Could I connect these boards together with following circuit?

Mark Edwards · ‎2014-06-12

Posted on June 12, 2014 at 21:24

I don't recognise that way of connecting CAN. This is how I do it.

Tesla DeLorean · ‎2014-06-12

Posted on June 12, 2014 at 22:44

The diode trick was pretty clever.

[DEAD LINK /public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Can-Bus%20Error&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&currentviews=141]https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=%2Fpublic%2FSTe2ecommunities%2Fmcu%2FLists%2Fcortex_mx_stm32%2FCan-Bus%20Error&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B?tviews=141

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evilrakshasa · ‎2014-12-12

Posted on December 12, 2014 at 09:28

I am using STM32F103C8 Controller. I want to use it as a CAN transmitter to send command to another device which will respond back with data.

I am using the following code to transmit data:

#include ''stm32f10x.h''

#include ''misc.h''

#include ''stm32f10x_can.h''

#include ''stm32f10x_rcc.h''

#include ''stm32f10x_gpio.h''

#define LED_PORT GPIOA

GPIO_InitTypeDef GPIO_InitStructure;

int i;

void NVIC_Configuration(void);

void CAN_Polling(void);

int main(void)

{

/* CAN1 Periph clock enable */

RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All;

GPIO_Init(LED_PORT, &GPIO_InitStructure);

/* NVIC Configuration */

NVIC_Configuration();

// for (i = 0; i < 2000000; i++);

/* CAN transmit at 100Kb/s and receive by polling in loopback mode */

CAN_Polling();

while(1)

{

}

void CAN_Polling(void)

{

CAN_InitTypeDef CAN_InitStructure;

CAN_FilterInitTypeDef CAN_FilterInitStructure;

CanTxMsg TxMessage;

uint8_t TransmitMailbox = 0;

/* CAN register init */

CAN_DeInit( CAN1);

CAN_StructInit(&CAN_InitStructure);

/* CAN cell init */

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_8tq;

CAN_InitStructure.CAN_BS2 = CAN_BS2_7tq;

CAN_InitStructure.CAN_Prescaler = 5;

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);

/* transmit */

TxMessage.StdId = 0x11;

TxMessage.RTR = CAN_RTR_DATA;

TxMessage.IDE = CAN_ID_STD;

TxMessage.DLC = 2;

TxMessage.Data[0] = 0xCA;

TxMessage.Data[1] = 0xFE;

TransmitMailbox = CAN_Transmit(CAN1, &TxMessage);

i = 0;

while ((CAN_TransmitStatus(CAN1, TransmitMailbox) != CANTXOK)

&& (i != 0xFF))

{

i++;

}

void NVIC_Configuration(void)

{

NVIC_InitTypeDef NVIC_InitStructure;

/* Enable CAN1 RX0 interrupt IRQ channel */

NVIC_InitStructure.NVIC_IRQChannel = USB_LP_CAN1_RX0_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

But there in no signal generated at the CANTX pin PA12. While debugging the std_id, data and DLC is being set but while transmitting, the TX0K is not being set and the status of the transmitter is shown as pending.

But if I run the same communication in loopback mode. The transmission is successful.

Please help.

Thanks

Tesla DeLorean · ‎2014-12-12

Posted on December 12, 2014 at 14:00

Yes, you'll need to be enabling the pins with a little more care. The CAN pins would need to be properly configured, and perhaps remapped depending on which ones you're using.

/* Configure CAN pin: RX */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_CAN_RX;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIO_CAN, &GPIO_InitStructure);
/* Configure CAN pin: TX */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_CAN_TX;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIO_CAN, &GPIO_InitStructure);
GPIO_PinRemapConfig(GPIO_Remapping_CAN , ENABLE); // If required, AFIO clock must also be enabled

See also STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\CAN\Networking\main.c

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evilrakshasa · ‎2014-12-12

Posted on December 13, 2014 at 07:46

Thank you for the quick response.

I read through the CAN example reference suggested by you and did some modifications in the existing code as:

#include ''stm32f10x.h''

#include ''misc.h''

#include ''stm32f10x_can.h''

#include ''stm32f10x_rcc.h''

#include ''stm32f10x_gpio.h''

CAN_InitTypeDef CAN_InitStructure;

CAN_FilterInitTypeDef CAN_FilterInitStructure;

CanTxMsg TxMessage;

uint8_t TransmitMailbox = 0;

void NVIC_Configuration(void);

void CAN_Polling(void);

int main(void)

{

NVIC_Configuration();

GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

/* Configure CAN pin: RX */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;

GPIO_Init(GPIOA, &GPIO_InitStructure);

/* Configure CAN pin: TX */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_PinRemapConfig(GPIO_Remap1_CAN1 , ENABLE);

/* CAN1 Periph clock enable */

RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);

CAN_Polling();

while(1)

{

TxMessage.Data[0] = 0x02;

CAN_Transmit(CAN1, &TxMessage);

uint16_t nTime = 0x0000;

for(nTime = 0; nTime <0xFFF; nTime++)

{

}

void CAN_Polling(void)

{

/* CAN register init */

CAN_DeInit( CAN1);

CAN_StructInit(&CAN_InitStructure);

/* CAN cell init */

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_3tq;

CAN_InitStructure.CAN_BS2 = CAN_BS2_5tq;

CAN_InitStructure.CAN_Prescaler = 8;

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);

/* transmit */

TxMessage.StdId = 0x321;

TxMessage.ExtId = 0x01;

TxMessage.RTR = CAN_RTR_DATA;

TxMessage.IDE = CAN_ID_STD;

TxMessage.DLC = 1;

CAN_ITConfig(CAN1, CAN_IT_FMP0, ENABLE);

}

void NVIC_Configuration(void)

{

NVIC_InitTypeDef NVIC_InitStructure;

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

/* Enable CAN1 RX0 interrupt IRQ channel */

NVIC_InitStructure.NVIC_IRQChannel = USB_HP_CAN1_TX_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

Now there is an error in transmission depicted by the setting of TERR0 bit.

I am also not sure about the baudrate setting to. How to check the clock frequency for the controller to set the BS1,BS2 and Prescalar values?

Thank You

evilrakshasa · ‎2014-12-16

Posted on December 17, 2014 at 05:25

The original post was too long to process during our migration. Please click on the provided URL to read the original post. https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I6gj&d=%2Fa%2F0X0000000btF%2Fwxs7axi078j7Nc9jjcT4.88751WCXXAl6PjNZIO.Zfk&asPdf=false

Tesla DeLorean · ‎2014-12-16

Posted on December 17, 2014 at 06:39

What tool chain are you using? You seem to have done some odd things with the project, as the peripheral #include files are typically pulled in via stm32f10x_conf.h, provided that's in your project directory and you have the right defines passed into the compiler. USE_STDPERIPH_DRIVER

You might want to review more carefully the project templates provided in the standard library

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evilrakshasa · ‎2014-12-16

Posted on December 17, 2014 at 07:14

I am using CooCox IDE. There I have selected my controller and then from the repository I have selected CAN template. So by default the CMSIS and CMSIS_boot header files are included in the project.

Tesla DeLorean · ‎2014-12-17

Posted on December 17, 2014 at 18:29

Perhaps you should take up compiler/project issues up with them then? I'm using Keil mostly, and Yagarto as my GNU/GCC tool chain.

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