使用ESP-IDF新i2c_master.h库与OV7670通信时出现硬件NACK错误

我正在编写程序通过I2C（SCCB）读取OV7670摄像头模块的寄存器值。使用旧版driver/i2c.h库时代码可成功执行并读取寄存器值，但使用新版driver/i2c_master.h库时出现硬件NACK错误。

使用的SCCB函数 #

static i2c_master_bus_handle_t bus_handle = NULL;
static i2c_master_dev_handle_t dev_handle = NULL;

void sccb_init()
{
    // Configure I2C bus
    i2c_master_bus_config_t bus_cfg = {
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .i2c_port = 0, // I2C_NUM_0
        .scl_io_num = I2C_MASTER_SCL_IO,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .glitch_ignore_cnt = 7,
        .flags.enable_internal_pullup = true,
    };
    ESP_ERROR_CHECK(i2c_new_master_bus(&bus_cfg, &bus_handle));

    // Configure SCCB device (OV7670 default address: 0x21 for write)
    i2c_device_config_t dev_cfg = {
        .dev_addr_length = I2C_ADDR_BIT_LEN_7,
        .device_address = 0x21, // OV7670 SCCB address
        .scl_speed_hz = I2C_MASTER_FREQ_HZ,
    };
    ESP_ERROR_CHECK(i2c_master_bus_add_device(bus_handle, &dev_cfg, &dev_handle));
}

esp_err_t sccb_write(uint8_t reg, uint8_t data)
{
    uint8_t write_buf[2] = {reg, data};
    return i2c_master_transmit(dev_handle, write_buf, sizeof(write_buf), I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
}
esp_err_t sccb_read(uint8_t reg, uint8_t *data)
{
    // Write register address first
    esp_err_t ret = i2c_master_transmit(dev_handle, &reg, 1, I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
    if (ret != ESP_OK)
        return ret;

    // Read data from register
    return i2c_master_receive(dev_handle, data, 1, I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
}
// UART functions

app_main函数 #

sccb_init();
ESP_LOGI(TAG, "SCCB initialized");

uart_init();
ESP_LOGI(TAG, "UART initialized");
while (1)
{
    // Send data to PC
    uart_write_bytes(UART_PORT, tx_data, strlen(tx_data));

    // Read data from PC (if available)
    int len = uart_read_bytes(UART_PORT, rx_data, BUF_SIZE, 1000 / portTICK_PERIOD_MS);
    if (len > 0)
    {
        rx_data[len] = '\0';
        printf("Received: %s\n", rx_data);
        uint32_t regi = atoi(rx_data);
        if (regi > 255)
        {
            ESP_LOGI(TAG, "Register value out of range");
            continue;
        }
        uint8_t reg = (uint8_t)regi;
        uint8_t data;
        vTaskDelay(100 / portTICK_PERIOD_MS);
        sccb_write(0x12, 0x80); // Reset COM7
        vTaskDelay(100 / portTICK_PERIOD_MS);
        if (sccb_read(reg, &data) == ESP_OK)
        {
            ESP_LOGI(TAG, "Read from register 0x%02X: 0x%02X", reg, data);
        }
        else
        {
            ESP_LOGE(TAG, "Failed to read from register 0x%02X", reg);
        }
    }
    vTaskDelay(1000 / portTICK_PERIOD_MS);
}

ESP32日志输出 #

I (298) main_task: Calling app_main()

D (298) i2c.coI (298) SCCB: UART initialized

Received: 12

E (7598) i2c.master: I2C hardware NACK detected

E (7598) i2c.master: I2C transaction unexpected nack detected

E (7598) i2c.master: s_i2c_synchronous_transaction(924): I2C transaction failed

E (7598) i2c.master: i2c_master_multi_buffer_transmit(1186): I2C transaction failed

E (7708) i2c.master: I2C hardware NACK detected

E (7708) i2c.master: I2C transaction unexpected nack detected

E (7708) i2c.master: s_i2c_synchronous_transaction(924): I2C transaction failed

E (7708) i2c.master: i2c_master_multi_buffer_transmit(1186): I2C transaction failed

E (7718) SCCB: Failed to read from register 0x0C

内容的提问来源于stack exchange，提问作者Hamim Mahmud