GD32 CAN — 多 CAN 通信

GD32 GD32F30x_Firmware_Library V3.0.3 CAN 多 CAN 通信 示例教学

CAN — 多 CAN 通信

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


功能简介

本示例演示 CAN 总线通信。CAN 是汽车和工业领域最常用的现场总线,支持多主通信、错误检测和自动重传。

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

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#include "gd32f30x.h"
#include <stdio.h>
#include "gd32f307c_eval.h"
#define CAN_BAUDRATE  1000

void nvic_config(void);
void led_config(void);
void can_gpio_config(void);
void can_config(void);

/*!
    \brief      main function
    \param[in]  none
    \param[out] none
    \retval     none
*/
int main(void)
{
    uint8_t i = 0;
    uint32_t timeout = 0xFFFF;
    uint8_t transmit_mailbox = 0;
    
    can0_receive_flag = RESET;
    can1_receive_flag = RESET;
    can0_error_flag = RESET;
    can1_error_flag = RESET;
    
    /* configure GPIO */
    can_gpio_config();
    
    /* configure NVIC */
    nvic_config();
    
    /* configure USART */
    gd_eval_com_init(EVAL_COM0);
    
    /* configure Wakeup key or Tamper key */
    gd_eval_key_init(KEY_WAKEUP, KEY_MODE_GPIO);
    gd_eval_key_init(KEY_TAMPER, KEY_MODE_GPIO);
    
    printf("\r\nGD32F30x dual CAN test, please press Wakeup key or Tamper key to start communication!\r\n");
    /* configure leds */
    led_config();
    gd_eval_led_off(LED2);
    gd_eval_led_off(LED3);
    gd_eval_led_off(LED4);
    gd_eval_led_off(LED5);
    
    /* initialize CAN and filter */
    can_config();
    /* enable can receive FIFO0 not empty interrupt */
    can_interrupt_enable(CAN0, CAN_INT_RFNE0);
    can_interrupt_enable(CAN1, CAN_INT_RFNE0);
    
    /* initialize transmit message */
    transmit_message.tx_sfid = 0x7ab;
    transmit_message.tx_efid = 0x00;
    transmit_message.tx_ft = CAN_FT_DATA;
    transmit_message.tx_ff = CAN_FF_STANDARD;
    transmit_message.tx_dlen = 8;
    
    transmit_message.tx_data[0] = 0x00;
    transmit_message.tx_data[1] = 0xA1;
    transmit_message.tx_data[2] = 0xA2;
    transmit_message.tx_data[3] = 0xA3;
    transmit_message.tx_data[4] = 0xA4;
    transmit_message.tx_data[5] = 0xA5;
    transmit_message.tx_data[6] = 0xA6;
    transmit_message.tx_data[7] = 0xA7;

    while(1){
        /* test whether the Tamper key is pressed */
        if(0 == gd_eval_key_state_get(KEY_TAMPER)){
            transmit_message.tx_data[0] = 0x55;
            transmit_message.tx_data[1] = 0xAA;
            printf("\r\n can0 transmit data:");
            for(i = 0; i < transmit_message.tx_dlen; i++){
                printf(" %02x", transmit_message.tx_data[i]);
            }
            
            /* transmit message */
            transmit_mailbox = can_message_transmit(CAN0, &transmit_message);
            /* waiting for transmit completed */
            timeout = 0xFFFF;
            while((CAN_TRANSMIT_OK != can_transmit_states(CAN0, transmit_mailbox)) && (0 != timeout)){
                timeout--;
            }
            /* waiting for the Tamper key up */
            while(0 == gd_eval_key_state_get(KEY_TAMPER));
        }
        
#ifdef GD32F30X_CL
        /* test whether the Wakeup key is pressed */
        if(0 == gd_eval_key_state_get(KEY_WAKEUP)){
            transmit_message.tx_data[0] = 0xAA;
            transmit_message.tx_data[1] = 0x55;
            printf("\r\n can1 transmit data:");
            for(i = 0; i < transmit_message.tx_dlen; i++){
                printf(" %02x", transmit_message.tx_data[i]);
            }
            /* transmit message */
            transmit_mailbox = can_message_transmit(CAN1, &transmit_message);
            /* waiting for transmit completed */
            timeout = 0xFFFF;
            while((CAN_TRANSMIT_OK != can_transmit_states(CAN1, transmit_mailbox)) && (0 != timeout)){
                timeout--;
            }
            /* waiting for the Wakeup key up */
            while(0 == gd_eval_key_state_get(KEY_WAKEUP));
        }
#endif /* GD32F30X_CL */
        /* CAN0 receive data correctly, the received data is printed */
        if(SET == can0_receive_flag){
            can0_receive_flag = RESET;
            printf("\r\n can0 receive data:");
            for(i = 0; i < receive_message.rx_dlen; i++){
                printf(" %02x", receive_message.rx_data[i]);
            }
            gd_eval_led_toggle(LED4);
        }
        
#ifdef GD32F30X_CL
        /* CAN1 receive data correctly, the received data is printed */
        if(SET == can1_receive_flag){
            can1_receive_flag = RESET;
            gd_eval_led_toggle(LED5);
            printf("\r\n can1 receive data:");
            for(i = 0; i < receive_message.rx_dlen; i++){
                printf(" %02x", receive_message.rx_data[i]);
            }
        }
#endif /* GD32F30X_CL */
        
        /* CAN0 error */
        if(SET == can0_error_flag){
            can0_error_flag = RESET;
            printf("\r\n can0 communication error");
        }
        
#ifdef GD32F30X_CL
        /* CAN1 error */
        if(SET == can1_error_flag){
            can1_error_flag = RESET;
            printf("\r\n can1 communication error");
        }
#endif /* GD32F30X_CL */
    }
}

void can_config()
{
    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(CAN0);
#ifdef GD32F30X_CL
    can_deinit(CAN1);
#endif /* GD32F30X_CL */
    
    /* initialize CAN parameters */
    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_NORMAL_MODE;
    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;
    
    /* 1MBps */
#if CAN_BAUDRATE == 1000
    can_parameter.prescaler = 6;
    /* 500KBps */
#elif CAN_BAUDRATE == 500
    can_parameter.prescaler = 12;
    /* 250KBps */
#elif CAN_BAUDRATE == 250
    can_parameter.prescaler = 24;
    /* 125KBps */
#elif CAN_BAUDRATE == 125
    can_parameter.prescaler = 48;
    /* 100KBps */
#elif  CAN_BAUDRATE == 100
    can_parameter.prescaler = 60;
    /* 50KBps */
#elif  CAN_BAUDRATE == 50
    can_parameter.prescaler = 120;
    /* 20KBps */
#elif  CAN_BAUDRATE == 20
    can_parameter.prescaler = 300;
#else
    #error "please select list can baudrate in private defines in main.c "
#endif  
    /* initialize CAN */
    can_init(CAN0, &can_parameter);
#ifdef GD32F30X_CL
    can_init(CAN1, &can_parameter);
#endif /* GD32F30X_CL */

    /* initialize filter */ 
    can_filter.filter_number=0;
    can_filter.filter_mode = CAN_FILTERMODE_MASK;
    can_filter.filter_bits = CAN_FILTERBITS_32BIT;
    can_filter.filter_list_high = 0x0000;
    can_filter.filter_list_low = 0x0000;
    can_filter.filter_mask_high = 0x0000;
    can_filter.filter_mask_low = 0x0000;
    can_filter.filter_fifo_number = CAN_FIFO0;
    can_filter.filter_enable = ENABLE;
    
    can_filter_init(&can_filter);
    
    /* CAN1 filter number */
    can_filter.filter_number = 15;
    can_filter_init(&can_filter);
}

void nvic_config(void)
{
#ifdef GD32F30X_CL
    /* configure CAN0 NVIC */
    nvic_irq_enable(CAN0_RX0_IRQn,0,0);

    /* configure CAN1 NVIC */
    nvic_irq_enable(CAN1_RX0_IRQn,1,1);
#else
    nvic_irq_enable(USBD_LP_CAN0_RX0_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);
}

void can_gpio_config(void)
{
    /* enable CAN clock */
    rcu_periph_clock_enable(RCU_CAN0);
#ifdef GD32F30X_CL
    rcu_periph_clock_enable(RCU_CAN1);
#endif /* GD32F30X_CL */
    rcu_periph_clock_enable(RCU_GPIOB);
    rcu_periph_clock_enable(RCU_GPIOD);
    rcu_periph_clock_enable(RCU_AF);
    
    /* configure CAN0 GPIO */
    gpio_init(GPIOD,GPIO_MODE_IPU,GPIO_OSPEED_50MHZ,GPIO_PIN_0);
    gpio_init(GPIOD,GPIO_MODE_AF_PP,GPIO_OSPEED_50MHZ,GPIO_PIN_1);
#ifdef GD32F30X_CL
    gpio_pin_remap_config(GPIO_CAN0_FULL_REMAP,ENABLE);
#else
    gpio_pin_remap_config(GPIO_CAN_FULL_REMAP,ENABLE);
#endif /* GD32F30X_CL */
    
#ifdef GD32F30X_CL
    /* configure CAN1 GPIO */
    gpio_init(GPIOB,GPIO_MODE_IPU,GPIO_OSPEED_50MHZ,GPIO_PIN_5);
    gpio_init(GPIOB,GPIO_MODE_AF_PP,GPIO_OSPEED_50MHZ,GPIO_PIN_6);
    gpio_pin_remap_config(GPIO_CAN1_REMAP,ENABLE);
#endif /* GD32F30X_CL */
}

代码讲解

printf 输出:通过串口打印调试信息。需要先调用 uart_print_init 完成重定向。

GPIO 配置:设置引脚为输出/输入模式,选择推挽/开漏输出,配置上拉/下拉。

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

  • 两块板子通过 CAN 总线交换数据
  • 通信成功 LED 指示
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