Error frame on TWAI initialization in espressif

36 views Asked by At

I use the twai and can successfully write and receive frames. However, when I reset the esp23 I see error frames showing up. It seems that the esp_tx pin sends a negative pulse on initialization which results in an error on the bus. How can I prevent this? You can see what happens in the screenshots I added.

This is the code I use to initialize the twai.

// Initialize configuration structures using macro initializers
    twai_general_config_t g_config = TWAI_GENERAL_CONFIG_DEFAULT( CAN_TX,CAN_RX, TWAI_MODE_NORMAL);
    g_config.tx_queue_len          = 10;
    twai_timing_config_t t_config  = TWAI_TIMING_CONFIG_100KBITS();
    twai_filter_config_t f_config  = TWAI_FILTER_CONFIG_ACCEPT_ALL();

    // Install TWAI driver
    // negative pulse occures in next function
    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;
    }

Board: ESP32-S3-DevKitC-1 v1.0 ESP-IDF: platform-espressif32 6.4.0 CAN transceiver: SN65HVD232DR esp_twai_tx_pin: GPIO_NUM_11 esp_twai_rx_pin: GPIO_NUM_12
Logic anayzer GPIO
savy can error messages

I tried to assign the TX pin as output before initialization, but it did not help as the pin is reinitialized in the driver initialization

    // Set CAN_RX pin as output and high
    gpio_set_direction(CAN_TX, GPIO_MODE_OUTPUT);
    gpio_set_level(CAN_TX, 1);

    // glitch is here
    // negative pulse occures in next function
    if (twai_driver_install(&g_config, &t_config, &f_config) == ESP_OK) {
        printf("Driver installed\n");
    } else {
        printf("Failed to install driver\n");
        return;
    }
0

There are 0 answers