Light 2 Click

Light 2 Click is a compact add-on board designed for accurate and flexible light measurement in various environments. This board features the ISL76682, a high-sensitivity, light-to-digital sensor with an I2C interface from Renesas, made specifically for automotive applications. Key features include a photodiode array that closely mimics the human eye's response, an ADC for flicker rejection, and four selectable light measurement ranges via I2C, enhancing both flexibility and accuracy. With a typical power consumption of 55µA in Standard mode and two power-down modes to minimize energy use, the board is efficient and adaptable to different lighting conditions.

Click Product page

Click library

• Author : Stefan Ilic
• Date : Nov 2023.
• Type : I2C type

Software Support

We provide a library for the Light 2 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Light 2 Click driver.

Standard key functions :

• light2_cfg_setup Config Object Initialization function.

  void light2_cfg_setup ( light2_cfg_t *cfg );

• light2_init Initialization function.

  err_t light2_init ( light2_t *ctx, light2_cfg_t *cfg );

• light2_default_cfg Click Default Configuration function.

  err_t light2_default_cfg ( light2_t *ctx );

Example key functions :

• light2_read_raw_data This function reads raw data from the ADC of Light 2 Click board.

  err_t light2_read_raw_data ( light2_t *ctx, uint16_t *data_out );

• light2_get_cal_const This function is used to get a calculation constant depending on Light 2 Click board configuration.

  err_t light2_get_cal_const ( light2_t *ctx );

• light2_get_light_data This function is used to read light data of Light 2 Click board configuration.

  err_t light2_get_light_data ( light2_t *ctx, float *light_data );

Example Description

This example demonstrates the use of Light 2 Click board by measuring the ambient light level in Lux.

The demo application is composed of two sections :

Application Init

Initializes the driver and performs the Click default configuration.

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    light2_cfg_t light2_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.
    light2_cfg_setup( &light2_cfg );
    LIGHT2_MAP_MIKROBUS( light2_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == light2_init( &light2, &light2_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( LIGHT2_ERROR == light2_default_cfg ( &light2 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
}

Application Task

Reads the ADC voltage and then calculates the illuminance from it. The calculated value of illuminance in lux is being displayed on the USB UART approximately once per second.

void application_task ( void ) 
{
    float lux_data = 0;

    light2_get_light_data( &light2, &lux_data );
    log_printf( &logger, " LUX data: %.2f LUX \r\n", lux_data );

    Delay_ms ( 1000 );
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Light2

Additional notes and informations

Depending on the development board you are using, you may need USB UART Click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.