ESP32 (ESP-IDF) "driver/twai.h" CAN Data Transmission is working but Receive function is not working using CAN/TWAI

Question

I saw a YouTube video with someone who used a similar code, and it was working perfectly for him (YouTube Video: link: https://youtu.be/bxzWuIqfn9Y). He used "driver/can.h" which has been removed from v5.0 of ESP-IDF because CAN and TWAI are the same.

More details: Issue raised on GitHub: https://github.com/espressif/esp-idf/issues/10757#issue-1582253298 IDF version used: v5.0 and v4.4.4 Operating System used: Windows IDE used to program and flash code: VS Code IDE

This is my code:

#include "driver/gpio.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "stdio.h"
#include "stdlib.h"
#include "driver/twai.h"

void twai_setup_and_install(){
    //Initialize configuration structures using macro initializers
    twai_general_config_t g_config = {
        .mode = TWAI_MODE_NORMAL,
        .tx_io = GPIO_NUM_5,
        .rx_io = GPIO_NUM_4,
        .clkout_io = TWAI_IO_UNUSED,
        .bus_off_io = TWAI_IO_UNUSED,
        .tx_queue_len = 5,
        .rx_queue_len = 5,
        .alerts_enabled = TWAI_ALERT_NONE,
        .clkout_divider = 0
    };

    twai_timing_config_t t_config = TWAI_TIMING_CONFIG_500KBITS();
    twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();

    // Install TWAI driver
    if (twai_driver_install(&g_config, &t_config, &f_config) == ESP_OK) {
        printf("Driver installed\n");
    } else {
        printf("Failed to install driver\n");
        return;
    }

    // Start TWAI driver
    if (twai_start() == ESP_OK) {
        printf("Driver started\n");
    } else {
        printf("Failed to start driver\n");
        return;
    }
}

void new_message(twai_message_t *message, uint32_t id, uint8_t dlc, uint8_t *data)
{
    
    message->flags = TWAI_MSG_FLAG_NONE;
    message->identifier = id;
    message->data_length_code = dlc;
    for (int i = 0; i < dlc; i++) {
        message->data[i] = data[i];
    }
    printf("Message created\nID: %ld DLC: %d Data:\t", message->identifier, message->data_length_code);
    for (int i = 0; i < message->data_length_code; i++) {
        printf("%d\t", message->data[i]);
    }
    printf("\n");
}

void transmit_message(twai_message_t *message)
{
    if (twai_transmit(message, pdMS_TO_TICKS(1000)) == ESP_OK) {
        printf("Message queued for transmission\n");
    } else {
        printf("Failed to send message\n");
    }
}

void receive_message(twai_message_t *message)
{
    if (twai_receive(message, pdMS_TO_TICKS(1000)) == ESP_OK) {
        printf("Message received:\n");
        printf("ID: %ld DLC: %d Data:\t", message->identifier, message->data_length_code);
        for (int i = 0; i < message->data_length_code; i++) {
            (message->extd)?printf("Extended ID"):printf("Standard ID");
            printf("%d\t", message->data[i]);
        }
    } else {
        printf("Failed to receive message\n");
    }
}

void app_main()
{
    
    twai_setup_and_install();
    twai_message_t message;
    twai_message_t message1;
    // Set the data to send
    uint8_t data[8] = {rand() % 255, rand() % 255, rand() % 255, 
    rand() % 255, rand() % 255, rand() % 255, rand() % 255, rand() % 255};

    while(true){ 
    // Create a new message
    new_message(&message, 0x123, 8, data);

    // Transmit the message to a queue
    transmit_message(&message);

    // Receive the message from the queue
    receive_message(&message1);

    // Wait for 1 second
    vTaskDelay(1000 / portTICK_PERIOD_MS);
    }

}

If anyone can help me as soon as possible, it would be really appreciated.

Sincere Regards.

Steps followed:

• I used ESP-IDF v5.0 with VS Code.
• I used the documentation to obtain the code for sender and receiver.
• I used a tested and functional MCP2515 module as my transceiver for the same.
• The Tx is broadcasting perfectly, but the Rx is not working for the above code.

Expected Output:

Message received:
ID: 0x123 DLC: 8 Data: 1 2 3 4 5 6 7 8
In my source code, I have implemented random data bits, so data may vary

Actual Output:

Failed to receive message

Answer 1

You are using the twai driver for the Twai controller on the ESP32, for the MCP2515 , you need the use the MCP_CAN library to receive messages over the SPI bus to the ESP32.