ESP32基于ESPIDF I2C设备探测和使用

• 📍I2C接口介绍和参考：https://docs.espressif.com/projects/esp-idf/zh_CN/stable/esp32/api-reference/peripherals/i2c.html

📓I2C 主机探测

• 主要主要利用 i2c_master_probe() 函数，来检测设备是否已经连接到 I2C 总线上。如果该函数返回 ESP_OK，则表示该设备已经被检测到。

单独使用发送数据函数i2c_master_transmit、i2c_master_transmit_receive() 函数，并不能有效检测到目标地址。

• 📝 I2C设备探测实现：

void i2c_scan_devices()
{
    uint8_t address;
    esp_err_t ret;
    bool found = false;
    ESP_LOGI("I2C", "Scanning I2C devices...");
    i2c_master_bus_config_t i2c_mst_config_1 = {
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .i2c_port = 0,
        .scl_io_num = EXAMPLE_PIN_NUM_SCL,
        .sda_io_num = EXAMPLE_PIN_NUM_SDA,
        .glitch_ignore_cnt = 7,
        .flags.enable_internal_pullup = true,
    };
    i2c_master_bus_handle_t bus_handle;

    for (address = 1; address < 127; address++)
    {
        ESP_ERROR_CHECK(i2c_new_master_bus(&i2c_mst_config_1, &bus_handle));
        ret = i2c_master_probe(bus_handle, (uint16_t)address, -1);// 探测设备
        ESP_ERROR_CHECK(i2c_del_master_bus(bus_handle));

        if (ret == ESP_OK)
        {
            ESP_LOGI("I2C", "Device found at address: 0x%02X", address);
            found = true;
        }

        vTaskDelay(100 / portTICK_PERIOD_MS);
    }
    if (!found)
    {
        ESP_LOGI("I2C", "No I2C devices found");
    }
}

• MPU6050
  
• I2C SSD1306
  
• AT24C02
  

AT24C02数据读取

• 驱动函数：

void at24c02_read_data(uint8_t mem_addr, uint8_t *data, size_t len) {
    i2c_master_dev_handle_t dev_handle;
    i2c_device_config_t dev_config = {
        .dev_addr_length = I2C_ADDR_BIT_LEN_7,
        .device_address = AT24C02_ADDR,
        .scl_speed_hz = I2C_MASTER_FREQ_HZ,
    };

    // 创建设备句柄
    esp_err_t ret = i2c_master_bus_add_device(bus_handle, &dev_config, &dev_handle);
    if (ret != ESP_OK) {
        ESP_LOGE("AT24C02", "Failed to add device: %s", esp_err_to_name(ret));
        return;
    }

    // 发送要读取的存储地址
    ret = i2c_master_transmit(dev_handle, &mem_addr, 1, 1000 / portTICK_PERIOD_MS);
    if (ret != ESP_OK) {
        ESP_LOGE("AT24C02", "Failed to send memory address: %s", esp_err_to_name(ret));
        i2c_master_bus_rm_device(dev_handle);
        return;
    }

    // 读取数据
    ret = i2c_master_receive(dev_handle, data, len, 1000 / portTICK_PERIOD_MS);
    if (ret != ESP_OK) {
        ESP_LOGE("AT24C02", "Failed to read data: %s", esp_err_to_name(ret));
    } else {
        ESP_LOGI("AT24C02", "Data read successfully");
    }

    // 删除设备句柄
    i2c_master_bus_rm_device(dev_handle);
}

• 📄读取数据

 i2c_master_init();

    uint8_t mem_addr = 0x00;  // 要读取的存储地址
    uint8_t data[35];         // 读取的数据缓冲区
    size_t len = sizeof(data);

    // 读取数据
    at24c02_read_data(mem_addr, data, len);

    // 打印读取的数据
    ESP_LOGI("AT24C02", "Data at address 0x%02X:", mem_addr);
    ESP_LOGI("AT24C02 Data[35]:", "%s", (char*)data);
    //清空数组
        memset(data, 0, sizeof(data));