How can I contact smt32f103vc and stm32f407 with CANBUS protocol without transceiver?

[kadir ustun1]

Hello everyone,

I want to contact STM32F103VC and STM32F407 with canbus protocol without transceiver.

I set baudrate 60kHz. but I can not send or receive data. Can you hel please ?

Thank you.

[kadir ustun1]

void InitCanBus(void){
    
    CAN_InitTypeDef  CanInitStruct;
    CAN_FilterInitTypeDef CAN_FilterInitStructure;
    NVIC_InitTypeDef   NVIC_InitStructure;
    
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);
    
    InitGPIOForCAN();
    CAN_DeInit(CAN1);
    //CAN_StructInit(&CanInitStruct);
    
    CanInitStruct.CAN_ABOM      = DISABLE;
    CanInitStruct.CAN_AWUM      = DISABLE;
    CanInitStruct.CAN_BS1       = CAN_BS1_5tq;
    CanInitStruct.CAN_BS2       = CAN_BS2_4tq;
    CanInitStruct.CAN_Mode      = CAN_Mode_Normal;
    CanInitStruct.CAN_NART      = DISABLE;
    CanInitStruct.CAN_Prescaler = 58;
    CanInitStruct.CAN_RFLM      = DISABLE;
    CanInitStruct.CAN_SJW       = CAN_SJW_1tq;
    CanInitStruct.CAN_TTCM      = DISABLE;
    CanInitStruct.CAN_TXFP      = DISABLE;
    
       
    if(CAN_Init(CAN1, &CanInitStruct))
    
    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=CAN_FIFO1;
    CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
    CAN_FilterInit(&CAN_FilterInitStructure);
 
    CAN_ITConfig(CAN1, CAN_IT_FMP1, ENABLE);
    CAN_ITConfig(CAN1, CAN_IT_TME, ENABLE);
    
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    NVIC_InitStructure.NVIC_IRQChannel = CAN1_RX1_IRQn;
    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);
    NVIC_EnableIRQ(CAN1_RX1_IRQn);
   // CAN_OperatingModeRequest(CAN1, 1);
}

This is my configure function for CANBUS

[kadir ustun1]

void InitGPIOForCAN(void){
    
    GPIO_InitTypeDef GPIO_InitStructure;
 
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);                                                               /* NOTE: GPIOA, GPIOB peripheral clock enable */
    
    GPIO_InitStructure.GPIO_Pin     = CAN_RX;
    GPIO_InitStructure.GPIO_Speed   = GPIO_Speed_50MHz;                                                                 /* NOTE: GPIO hizi 50 Mhz */
    GPIO_InitStructure.GPIO_Mode    = GPIO_Mode_AF_PP;                                                                  /* NOTE: Cikis modu, push pull */
    GPIO_Init(CAN_PORT, &GPIO_InitStructure);
    
    GPIO_InitStructure.GPIO_Pin     = CAN_TX;
    GPIO_InitStructure.GPIO_Speed   = GPIO_Speed_50MHz;                                                                 /* NOTE: GPIO hizi 50 Mhz */
    GPIO_InitStructure.GPIO_Mode    = GPIO_Mode_AF_PP;                                                                 /* NOTE: Cikis modu, push pull */
    GPIO_Init(CAN_PORT, &GPIO_InitStructure);
    
    //GPIO_PinRemapConfig(GPIO_Remap1_CAN1, ENABLE);
    //GPIO_PinRemapConfig(GPIO_Remap2_CAN1, ENABLE);
    
}

and, this is my pin configure function

[kadir ustun1]

you think, this configuration is wrong for stm32f103 ?

[kadir ustun1]

you think, is configure wrong for STM32F103?

[kadir ustun1]

you think, Is configure wrong for STM32F103?

[Tesla DeLorean]

What pins?

I'd hazard this isn't clocking at 60 KHz. If the APB1 clock is 36 MHz, perhaps closer to 62 KHz

Like I said, you need to be talking to some other device on the bus, and it needs to respond.

I'd usually start by having CAN1 talk to CAN2 on the same system

I posted some CAN demo code for the F2 and F4 using the SPL to the forum many years back.

[kadir ustun1]

Pins are pa11 and pa12.​ mcu's frequency is 72 mhz. Bus frequency iş 36 mhz. And ı set canbus baudrate 50 khz. Stm32f4 can talk stm32f7. But stm32f103 cant talk. It can not send data.

[kadir ustun1]

Hello again.

I try to do this on cubemx. Now, I can send data but I can not receive data. I compare F4 and F1. And I saw that F4's rx pin mode: "alternate function push pul" but f1's rx pin mode :"Input mode". When I cahange it as alternate, Canbus does not init. so I think does not f1 work without tranciever. What do you think about that ?