# ESP32 ESP-IDF component for BH1750 ambient light sensor

## Features

1. I2C interface with configurable frequency up to 400 kHz (Fast Mode).
2. Support for two I2C addresses: 0x23 (ADDR low) and 0x5C (ADDR high).
3. One-time H-resolution measurement with 1 lux step.
4. Built-in error statistics tracking and reset for diagnostics.
5. Automatic lux conversion from raw sensor data.
6. Sensor presence verification during initialization via I2C probe.
7. Support multiple sensors on one device with [zh_pca9548a](https://github.com/aZholtikov/zh_pca9548a).

## Note

Enable the following settings in menuconfig:

```text
I2C_ISR_IRAM_SAFE
I2C_MASTER_ISR_HANDLER_IN_IRAM
```

## Using

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

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

In the application, add the component:

```c
#include "zh_bh1750.h"
```

## Example

```c
#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;
    i2c_new_master_bus(&i2c_bus_config, &i2c_bus_handle);
    zh_bh1750_init_config_t config = ZH_BH1750_INIT_CONFIG_DEFAULT();
    config.i2c_handle = i2c_bus_handle;
    zh_bh1750_init(&config, &bh1750_handle);
    float lux = 0.0;
    for (;;)
    {
        zh_bh1750_read(&bh1750_handle, &lux);
        printf("Lux %0.2f\n", lux);
        const zh_bh1750_stats_t *stats = zh_bh1750_get_stats();
        printf("Number of i2c driver error: %ld.\n", stats->i2c_driver_error);
        vTaskDelay(5000 / portTICK_PERIOD_MS);
    }
}
```