GD32 CAN — CAN 自回环

Tue, 08 Sep 2026 14:52:21 +0800

CAN — CAN 自回环

固件库: GD32F30x_Firmware_Library V3.0.3
芯片: GD32
源文件: GD32F30x_Firmware_Library_V3.0.3/Examples/CAN/communication_Loopback/main.c

功能简介

本示例演示 CAN 自回环测试。TX 发出的数据直接回到 RX，不需要外部 CAN 收发器，非常适合验证 CAN 配置是否正确。

硬件准备

CAN 收发器模块（如 TJA1050、MCP2551）
自回环测试模式下可不接外部设备

完整代码

#include "gd32f30x.h"
#include <stdio.h>
#include "gd32f307c_eval.h"
#define DEV_CAN0_USED

void nvic_config(void);
void led_config(void);
ErrStatus can_loopback(void);
ErrStatus can_loopback_interrupt(void);
void can_loopback_init(void);

/*!
    \brief      main function
    \param[in]  none
    \param[out] none
    \retval     none
*/
int main(void)
{
    /* enable CAN clock */
    rcu_periph_clock_enable(RCU_CAN0);
#ifdef GD32F30X_CL
    rcu_periph_clock_enable(RCU_CAN1);
#endif /* GD32F30X_CL */
    
    /* configure NVIC */
    nvic_config();
    
    /* configure leds */
    led_config();
    /* set all the leds off */
    gd_eval_led_off(LED2);
    gd_eval_led_off(LED3);
    gd_eval_led_off(LED4);
    gd_eval_led_off(LED5);
    /* loopback of polling */
    test_flag = can_loopback();
 
    if(SUCCESS == test_flag){
        /* loopback test is success */
        gd_eval_led_on(LED2);
        gd_eval_led_on(LED3);
    }else{
        /* loopback test is failed */
        gd_eval_led_off(LED2);
        gd_eval_led_off(LED3);
    }
    /* loopback of interrupt */
    test_flag_interrupt = can_loopback_interrupt();

    if(SUCCESS == test_flag_interrupt){
        /* interrupt loopback test is success */
        gd_eval_led_on(LED4);
        gd_eval_led_on(LED5);
    }else{
        /* interrupt loopback test is failed */
        gd_eval_led_off(LED4);
        gd_eval_led_off(LED5);
    }
    while (1);
}

void can_loopback_init(void)
{
    can_parameter_struct        can_parameter;
    can_filter_parameter_struct can_filter;
    
    can_struct_para_init(CAN_INIT_STRUCT, &can_parameter);
    can_struct_para_init(CAN_FILTER_STRUCT, &can_filter);
    
    /* initialize CAN register */
    can_deinit(CANX);
    
    /* initialize CAN */
    can_parameter.time_triggered = DISABLE;
    can_parameter.auto_bus_off_recovery = ENABLE;
    can_parameter.auto_wake_up = DISABLE;
    can_parameter.auto_retrans = ENABLE;
    can_parameter.rec_fifo_overwrite = DISABLE;
    can_parameter.trans_fifo_order = DISABLE;
    can_parameter.working_mode = CAN_LOOPBACK_MODE;
    /* configure baudrate to 125kbps */
    can_parameter.resync_jump_width = CAN_BT_SJW_1TQ;
    can_parameter.time_segment_1 = CAN_BT_BS1_7TQ;
    can_parameter.time_segment_2 = CAN_BT_BS2_2TQ;
    can_parameter.prescaler = 48;
    can_init(CANX, &can_parameter);

    /* initialize filter */
#ifdef  DEV_CAN0_USED
    /* CAN0 filter number */
    can_filter.filter_number = 0;
#else
    /* CAN1 filter number */
    can_filter.filter_number = 14;
#endif
    /* initialize filter */    
    can_filter.filter_mode = CAN_FILTERMODE_MASK;
    can_filter.filter_bits = CAN_FILTERBITS_32BIT;
    can_filter.filter_list_high = (uint16_t)(DEV_CAN_POLLING_ID << 5);
    can_filter.filter_list_low = 0x0000;
    /* ID and standard frame matched */
    can_filter.filter_mask_high = (uint16_t)(0x7FF << 5);
    can_filter.filter_mask_low = (uint16_t)(1U << 2);
    
    can_filter.filter_fifo_number = CAN_FIFO1;
    can_filter.filter_enable=ENABLE;
    can_filter_init(&can_filter);
    
    /* initialize filter */
#ifdef  DEV_CAN0_USED
    /* CAN0 filter number */
    can_filter.filter_number = 1;
#else
    /* CAN1 filter number */
    can_filter.filter_number = 15;
#endif
    /* initialize filter */
    can_filter.filter_mode = CAN_FILTERMODE_MASK;
    can_filter.filter_bits = CAN_FILTERBITS_32BIT;
    /* ID and extend frame matched */
    can_filter.filter_list_high = (uint16_t)(DEV_CAN_INTERRUPT_ID >> 13);
    can_filter.filter_list_low = (uint16_t)(((uint16_t)DEV_CAN_INTERRUPT_ID << 3) | (1U << 2));
    can_filter.filter_mask_high = (uint16_t)(0x1FFFFFFF >> 13);
    can_filter.filter_mask_low = (uint16_t)(((uint16_t)0x1FFFFFFF << 3) | (1U << 2));
    can_filter.filter_fifo_number = CAN_FIFO1;
    can_filter.filter_enable=ENABLE;
    can_filter_init(&can_filter);
}

void nvic_config(void)
{
    /* configure CAN0 NVIC */
    nvic_irq_enable(CAN0_RX1_IRQn,0,0);
#ifdef GD32F30X_CL
    /* configure CAN1 NVIC */
    nvic_irq_enable(CAN1_RX1_IRQn,0,0);
#endif /* GD32F30X_CL */
}

void led_config(void)
{
    gd_eval_led_init(LED2);
    gd_eval_led_init(LED3);
    gd_eval_led_init(LED4);
    gd_eval_led_init(LED5);
}

代码讲解

中断优先级配置：NVIC 设置中断的抢占优先级和子优先级。数字越小优先级越高。

实验现象

CAN 自回环：发送的报文直接回到接收端
校验通过 LED 亮起

Communication_Loopback on CLing

GD32 CAN — CAN 自回环

CAN — CAN 自回环

功能简介

硬件准备

完整代码

代码讲解

实验现象