我对如何在STM32F4Discovery上接收CAN消息感到迷茫。我在Silent_Loopback模式下使用它，这意味着所有发送的消息都应该到达CAN控制器本身。我发送消息时会收到Transmit_OK状态，但FIFO邮箱中没有任何内容。我已跳过CAN过滤器配置，以便接收所有消息，而不是过滤掉任何消息。我做错了什么？
/* Includes */
#include "stm32f4xx.h"
#include "stm32f4_discovery.h"
void Delay(__IO uint32_t nCount) {
while(nCount--) {
}
}
void RCC_Configuration(void) {
/* ENABLE CLOCKS */
/* GPIOB clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
/* USART3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
/* CAN1 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);
/* CAN2 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN2, ENABLE);
}
void GPIO_Configuration(void) {
GPIO_InitTypeDef GPIO_InitStructureUSART;
GPIO_InitTypeDef GPIO_InitStructureCAN_RX;
GPIO_InitTypeDef GPIO_InitStructureCAN_TX;
/* GPIO USART Configuration */
GPIO_InitStructureUSART.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
GPIO_InitStructureUSART.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructureUSART.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructureUSART.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructureUSART.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructureUSART);
/* Connect USART to AF */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_USART3); //USART_TX = PB10
GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_USART3); //USART_RX = PB11
/* GPIO CAN_RX Configuration */
GPIO_InitStructureCAN_RX.GPIO_Pin = GPIO_Pin_12;
GPIO_InitStructureCAN_RX.GPIO_Mode = GPIO_Mode_AF;
//GPIO_InitStructureCAN_TX.GPIO_OType = GPIO_OType_PP;
//GPIO_InitStructureCAN_TX.GPIO_PuPd = GPIO_PuPd_NOPULL;
//GPIO_InitStructureCAN_TX.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructureCAN_RX);
/* GPIO CAN_TX Configuration */
GPIO_InitStructureCAN_TX.GPIO_Pin = GPIO_Pin_13;
GPIO_InitStructureCAN_TX.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructureCAN_TX.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructureCAN_TX.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructureCAN_TX.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructureCAN_TX);
/* Connect CAN_RX & CAN_TX to AF9 */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource12, GPIO_AF_CAN2); //CAN_RX = PB12
GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_CAN2); //CAN_TX = PB13
}
void USART_Configuration(void) {
USART_InitTypeDef USART_InitStructure;
/* USART3 configuration */
/* 256000 baud, window 8 data bits, one stop bit, no parity, no hardware flow control, rx/tx enabled */
USART_InitStructure.USART_BaudRate = 256000;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART3, &USART_InitStructure);
USART_Cmd(USART3, ENABLE);
}
void CAN_Configuration(void) {
CAN_InitTypeDef CAN_InitStructure;
/* CAN2 reset */
CAN_DeInit(CAN2);
/* CAN2 configuration */
CAN_InitStructure.CAN_TTCM = DISABLE; // Time-triggered communication mode = DISABLED
CAN_InitStructure.CAN_ABOM = DISABLE; // Automatic bus-off management mode = DISABLED
CAN_InitStructure.CAN_AWUM = DISABLE; // Automatic wake-up mode = DISABLED
CAN_InitStructure.CAN_NART = DISABLE; // Non-automatic retransmission mode = DISABLED
CAN_InitStructure.CAN_RFLM = DISABLE; // Receive FIFO locked mode = DISABLED
CAN_InitStructure.CAN_TXFP = DISABLE; // Transmit FIFO priority = DISABLED
CAN_InitStructure.CAN_Mode = CAN_Mode_Silent_LoopBack; // Normal CAN mode
CAN_InitStructure.CAN_SJW = CAN_SJW_1tq; // Synchronization jump width = 1
CAN_InitStructure.CAN_BS1 = CAN_BS1_14tq; //14
CAN_InitStructure.CAN_BS2 = CAN_BS2_6tq; //6
CAN_InitStructure.CAN_Prescaler = 4; // Baudrate 500 kbps
//CAN_InitStructure.CAN_Prescaler = 16; // Baudrate 125 kbps
if (CAN_Init(CAN2, &CAN_InitStructure)) { // Initialize CAN
STM_EVAL_LEDInit(LED6); // Initialize and
STM_EVAL_LEDOn(LED6); // Turn ON blue LED if CAN initialization is successful
}
}
void CAN_FilterConfiguration(void) {
CAN_FilterInitTypeDef CAN_FilterInitStructure;
/* CAN2 filter configuration */
CAN_FilterInitStructure.CAN_FilterNumber = 0; // Filter number = 0 (0<=x<=13)
CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask; // Filter mode = identifier mask based filtering
CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_16bit;
CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0300 << 5; //0x0000;
CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x03FF << 5;
CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FIFO0; // FIFO = 0
CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
CAN_FilterInit(&CAN_FilterInitStructure);
}
void CAN_TxMessage(void) {
CanTxMsg TxMessage;
/* CAN message to send */
TxMessage.StdId = 0x321;
TxMessage.ExtId = 0x01;
TxMessage.RTR = CAN_RTR_DATA;
TxMessage.IDE = CAN_ID_STD;
TxMessage.DLC = 8;
TxMessage.Data[0] = 0x04;
TxMessage.Data[1] = 0x01;
TxMessage.Data[2] = 0x00;
TxMessage.Data[3] = 0x00;
TxMessage.Data[4] = 0x00;
TxMessage.Data[5] = 0x00;
TxMessage.Data[6] = 0x00;
TxMessage.Data[7] = 0x00;
//while (1) {
CAN_TransmitStatus(CAN2, 0);
CAN_Transmit(CAN2, &TxMessage);
if(CAN_TransmitStatus(CAN2, 0)){
STM_EVAL_LEDInit(LED4); // Initialize and
STM_EVAL_LEDOn(LED4); // turn ON green LED if transmit was successful
}
//}
}
void CAN_OBDII_RequestCurrentData(int PIDNumber) {
CanTxMsg TxMessage;
TxMessage.StdId = 0x7DF; // PID request identifier
TxMessage.ExtId = 0x7DF;
TxMessage.RTR = CAN_RTR_DATA;
TxMessage.IDE = CAN_ID_STD;
TxMessage.DLC = 8;
TxMessage.Data[0] = 0x02; // Number of additional bytes = 2
TxMessage.Data[1] = 0x01; // Show current data = 1
TxMessage.Data[2] = PIDNumber; // PID code number
TxMessage.Data[3] = 0x00;
TxMessage.Data[4] = 0x00;
TxMessage.Data[5] = 0x00;
TxMessage.Data[6] = 0x00;
TxMessage.Data[7] = 0x00;
CAN_Transmit(CAN2, &TxMessage); // Transmit OBDII PID request via CAN2/mailbox0
}
void CAN_RxMessage(void) {
CanRxMsg RxMessage;
int d0=0;
while(1) {
CAN_Receive(CAN2,CAN_FIFO0,&RxMessage);
d0 = RxMessage.Data[0];
d0 = RxMessage.Data[1];
d0 = RxMessage.Data[2];
d0 = RxMessage.Data[3];
d0 = RxMessage.Data[4];
d0 = RxMessage.Data[5];
d0 = RxMessage.Data[6];
d0 = RxMessage.Data[7];
}
}
int main(void)
{
/* Initialize Clocks */
RCC_Configuration();
/* Initialize GPIO */
GPIO_Configuration();
/* Initialize USART */
USART_Configuration();
/* Initialize CAN */
CAN_Configuration();
/* Initialize CAN Reception Filter */
//CAN_FilterConfiguration();
/* Transfer CAN message */
CAN_TxMessage();
/* Receive CAN message */
CAN_RxMessage();
答案 0 :(得分：0)
您必须配置过滤器以接受所有邮件（如果您没有任何过滤器，则不接受任何邮件）。但在您的示例中，您使用的是CAN2，因此FilterNumber必须为14或更高。
#define CAN_FIFO_ID 0
#define CAN_FIFO CAN_FIFO0
#define CAN_FIFO_IN CAN_IT_FMP0
/**
* @brief Default filter - accept all to CAN_FIFO
*/
void CAN_SetFilter()
{
/* Default filter - accept all to CAN_FIFO*/
CAN_FilterInitTypeDef CAN_FilterInitStructure;
CAN_FilterInitStructure.CAN_FilterNumber = 14; // 0..13 for CAN1, 14..27 for CAN2
CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FIFO;
CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;
CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_16bit;
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_FIFO_ID;
CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
CAN_FilterInit(&CAN_FilterInitStructure);
}
答案 1 :(得分：0)
分配给CAN1和CAN2的滤波器数量在CAN_FMR寄存器中定义，默认情况下，该寄存器设置为14，这是CAN2滤波器的起点。
这可以设置为28，这意味着没有过滤器到CAN2和所有28到CAN1或如果设置为0，所有28个过滤器都分配给CAN2。
答案 2 :(得分：0)
通常，在遮罩模式下（如果您具有有效的过滤器编号），任何遮罩= 0将使所有内容通过。