LED Driver 14 Click

LED Driver 14 Click is a compact add-on board that simplifies the control of multiple LEDs. This board features the BD18337EFV-M, a reliable four-channel constant current LED driver from Rohm Semiconductor. It is powered by an external power supply in the range of 5.5V to 20V, providing a maximum output current of 150mA per channel. The BD18337EFV-M also comes with the possibility for up to 3 LEDs in series on its output OUTx pin and built-in energy sharing control, selectable operational mode, and multiple built-in protection functions that protect the circuit during abnormalities. This Click board™ is ideal for LED rear lamps (turn/stop), fog lamps, and turn signals for automotive applications.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Jan 2022.
• Type : I2C type

Software Support

We provide a library for the LED Driver 14 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 LED Driver 14 Click driver.

Standard key functions :

• leddriver14_cfg_setup Config Object Initialization function.

  void leddriver14_cfg_setup ( leddriver14_cfg_t *cfg );

• leddriver14_init Initialization function.

  err_t leddriver14_init ( leddriver14_t *ctx, leddriver14_cfg_t *cfg );

• leddriver14_default_cfg Click Default Configuration function.

  err_t leddriver14_default_cfg ( leddriver14_t *ctx );

Example key functions :

• leddriver14_set_rset This function sets the resistance of the selected rset channel.

  err_t leddriver14_set_rset ( leddriver14_t *ctx, uint8_t rset, uint16_t res_ohm );

• leddriver14_get_int_pin This function returns the int pin logic state.

  uint8_t leddriver14_get_int_pin ( leddriver14_t *ctx );

• leddriver14_set_duty_cycle This function sets the PWM duty cycle in percentages ( Range[ 0..1 ] ).

  err_t leddriver14_set_duty_cycle ( leddriver14_t *ctx, float duty_cycle );

Example Description

This example demonstrates the use of LED Driver 14 Click board by controlling the brightness of LEDs by changing the PWM Duty Cycle.

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. */
    leddriver14_cfg_t leddriver14_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.
    leddriver14_cfg_setup( &leddriver14_cfg );
    LEDDRIVER14_MAP_MIKROBUS( leddriver14_cfg, MIKROBUS_1 );
    err_t init_flag = leddriver14_init( &leddriver14, &leddriver14_cfg );
    if ( ( I2C_MASTER_ERROR == init_flag ) || ( PWM_ERROR == init_flag ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( LEDDRIVER14_ERROR == leddriver14_default_cfg ( &leddriver14 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

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

Application Task

Adjusts the LEDs' brightness by changing the PWM duty cycle every 500ms. A duty cycle value is being displayed on the USB UART.

void application_task ( void )
{
    static int8_t duty_cnt = 1;
    static int8_t duty_inc = 1;
    float duty = duty_cnt / 10.0;

    leddriver14_set_duty_cycle ( &leddriver14, duty );
    log_printf( &logger, "> Duty: %d%%\r\n", ( uint16_t )( duty_cnt * 10 ) );

    if ( 10 == duty_cnt ) 
    {
        duty_inc = -1;
    }
    else if ( 0 == duty_cnt ) 
    {
        duty_inc = 1;
    }
    duty_cnt += duty_inc;

    if ( !leddriver14_get_int_pin ( &leddriver14 ) )
    {
        log_info ( &logger, " Abnormality such as LED Open or the OUTx pin short circuit occured " );
    }

    Delay_ms ( 500 );
}

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.LEDDriver14

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.