ESP32 ESP-IDF component for BH1750 ambient light sensor

Features

1. Measurement of ambient light intensity in lux.
2. I2C interface with frequency up to 400 kHz (Fast Mode).
3. Support for two I2C addresses: 0x23 (ADDR low) and 0x5C (ADDR high).
4. One-time H-resolution measurement with 1 lux step.
5. Automatic lux conversion from raw sensor data.
6. Sensor presence verification during initialization via I2C probe.
7. Built-in I2C error statistics tracking and reset for diagnostics.

Attention

1. The I2C bus must be initialized before the component.
2. Only one-time H-resolution measurement mode is supported.
3. Each read is a blocking call of approximately 180 ms.
4. Error statistics are global for all sensor instances on the device.

Using

In an existing project, run the following command to install the component:

cd ../your_project/components
git clone https://github.com/aZholtikov/zh_bh1750

In the application, add the component:

#include "zh_bh1750.h"

Examples

Basic Read Example

#include "zh_bh1750.h"

#define I2C_PORT (I2C_NUM_MAX - 1)

zh_bh1750_handle_t *bh1750_handle = NULL;

void app_main(void)
{
    esp_log_level_set("zh_bh1750", ESP_LOG_ERROR);
    i2c_master_bus_config_t i2c_bus_config = {
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .i2c_port = I2C_PORT,
        .scl_io_num = GPIO_NUM_22,
        .sda_io_num = GPIO_NUM_21,
        .glitch_ignore_cnt = 7,
        .flags.enable_internal_pullup = true,
    };
    i2c_master_bus_handle_t i2c_bus_handle = NULL;
    esp_err_t ret = i2c_new_master_bus(&i2c_bus_config, &i2c_bus_handle);
    if (ret != ESP_OK)
    {
        printf("I2C bus initialization error\n");
        return;
    }
    zh_bh1750_init_config_t config = ZH_BH1750_INIT_CONFIG_DEFAULT();
    config.i2c_handle = i2c_bus_handle;
    ret = zh_bh1750_init(&config, &bh1750_handle);
    if (ret != ESP_OK)
    {
        printf("BH1750 initialization error: %s\n", esp_err_to_name(ret));
        return;
    }
    float lux = 0.0;
    for (;;)
    {
        ret = zh_bh1750_read(&bh1750_handle, &lux);
        if (ret == ESP_OK)
        {
            printf("Lux: %0.2f\n", lux);
        }
        else
        {
            printf("Read error: %s\n", esp_err_to_name(ret));
        }
        vTaskDelay(5000 / portTICK_PERIOD_MS);
    }
}

---

Alternative Address Example

#include "zh_bh1750.h"

#define I2C_PORT (I2C_NUM_MAX - 1)

zh_bh1750_handle_t *bh1750_handle = NULL;

void app_main(void)
{
    esp_log_level_set("zh_bh1750", ESP_LOG_ERROR);
    i2c_master_bus_config_t i2c_bus_config = {
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .i2c_port = I2C_PORT,
        .scl_io_num = GPIO_NUM_22,
        .sda_io_num = GPIO_NUM_21,
        .glitch_ignore_cnt = 7,
        .flags.enable_internal_pullup = true,
    };
    i2c_master_bus_handle_t i2c_bus_handle = NULL;
    esp_err_t ret = i2c_new_master_bus(&i2c_bus_config, &i2c_bus_handle);
    if (ret != ESP_OK)
    {
        printf("I2C bus initialization error\n");
        return;
    }
    zh_bh1750_init_config_t config = ZH_BH1750_INIT_CONFIG_DEFAULT();
    config.i2c_handle = i2c_bus_handle;
    config.i2c_address = 0x5C;
    ret = zh_bh1750_init(&config, &bh1750_handle);
    if (ret != ESP_OK)
    {
        printf("BH1750 initialization error: %s\n", esp_err_to_name(ret));
        return;
    }
    float lux = 0.0;
    ret = zh_bh1750_read(&bh1750_handle, &lux);
    if (ret == ESP_OK)
    {
        printf("Lux: %0.2f\n", lux);
    }
    else
    {
        printf("Read error: %s\n", esp_err_to_name(ret));
    }
    ret = zh_bh1750_deinit(&bh1750_handle);
    if (ret != ESP_OK)
    {
        printf("Deinitialization error: %s\n", esp_err_to_name(ret));
    }
}

---

Error Statistics Example

#include "zh_bh1750.h"

#define I2C_PORT (I2C_NUM_MAX - 1)

zh_bh1750_handle_t *bh1750_handle = NULL;

void app_main(void)
{
    esp_log_level_set("zh_bh1750", ESP_LOG_ERROR);
    i2c_master_bus_config_t i2c_bus_config = {
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .i2c_port = I2C_PORT,
        .scl_io_num = GPIO_NUM_22,
        .sda_io_num = GPIO_NUM_21,
        .glitch_ignore_cnt = 7,
        .flags.enable_internal_pullup = true,
    };
    i2c_master_bus_handle_t i2c_bus_handle = NULL;
    esp_err_t ret = i2c_new_master_bus(&i2c_bus_config, &i2c_bus_handle);
    if (ret != ESP_OK)
    {
        printf("I2C bus initialization error\n");
        return;
    }
    zh_bh1750_init_config_t config = ZH_BH1750_INIT_CONFIG_DEFAULT();
    config.i2c_handle = i2c_bus_handle;
    ret = zh_bh1750_init(&config, &bh1750_handle);
    if (ret != ESP_OK)
    {
        printf("BH1750 initialization error: %s\n", esp_err_to_name(ret));
        return;
    }
    float lux = 0.0;
    for (int i = 0; i < 10; i++)
    {
        ret = zh_bh1750_read(&bh1750_handle, &lux);
        if (ret == ESP_OK)
        {
            printf("Lux: %0.2f\n", lux);
        }
        else
        {
            printf("Read error: %s\n", esp_err_to_name(ret));
        }
        const zh_bh1750_stats_t *stats = zh_bh1750_get_stats();
        printf("Number of I2C driver errors: %lu\n", (unsigned long)stats->i2c_driver_error);
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
    zh_bh1750_reset_stats();
    const zh_bh1750_stats_t *stats = zh_bh1750_get_stats();
    printf("Number of I2C driver errors after reset: %lu\n", (unsigned long)stats->i2c_driver_error);
    zh_bh1750_deinit(&bh1750_handle);
}