Buck 18 Click

Buck 18 Click is a compact add-on board for step-down voltage conversion in power-sensitive applications. This board features the MAXM38643, an ultra-low-IQ nanoPower buck module from Analog Devices, providing highly efficient voltage regulation with minimal power consumption. The board supports input voltages from 1.8V to 5.5V, converting them to output voltages between 0.7V and 3.3V. Users can manually adjust the output voltage through an onboard TRIM trimmer or digitally via the AD5171 digital potentiometer controlled through an I2C interface.

Click Product page

Click library

• Author : Nenad Filipovic
• Date : Jan 2024.
• Type : ADC/I2C type

Software Support

We provide a library for the Buck 18 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 Buck 18 Click driver.

Standard key functions :

• buck18_cfg_setup Config Object Initialization function.

  void buck18_cfg_setup ( buck18_cfg_t *cfg );

• buck18_init Initialization function.

  err_t buck18_init ( buck18_t *ctx, buck18_cfg_t *cfg );

• buck18_default_cfg Click Default Configuration function.

  err_t buck18_default_cfg ( buck18_t *ctx );

Example key functions :

• buck18_set_vout This function sets the voltage output level.

  err_t buck18_set_vout ( buck18_t *ctx, buck18_vout_t vout );

• buck18_read_voltage This function reads raw ADC value and converts it to proportional voltage level.

  err_t buck18_read_voltage ( buck18_t *ctx, float *voltage );

• buck18_enable This function turns on the power switch and enables the buck mode.

  void buck18_enable ( buck18_t *ctx );

Example Description

This example demonstrates the use of the Buck 18 Click board by changing the output voltage.

The demo application is composed of two sections :

Application Init

Initialization of I2C module and log UART. After driver initialization, the app executes a default configuration.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    buck18_cfg_t buck18_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.
    buck18_cfg_setup( &buck18_cfg );
    BUCK18_MAP_MIKROBUS( buck18_cfg, MIKROBUS_1 );
    err_t init_flag = buck18_init( &buck18, &buck18_cfg );
    if ( ( ADC_ERROR == init_flag ) || ( I2C_MASTER_ERROR == init_flag ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( BUCK18_ERROR == buck18_default_cfg ( &buck18 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

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

Application Task

The demo application changes the output voltage and displays the current voltage output value. Results are being sent to the UART Terminal, where you can track their changes.

void application_task ( void ) 
{
    for ( buck18_vout_t vout = BUCK18_VOUT_3V3; vout <= BUCK18_VOUT_0V9; vout++ )
    {
        if ( BUCK18_OK == buck18_set_vout( &buck18, vout ) )
        {
            float voltage = 0;
            if ( BUCK18_OK == buck18_read_voltage( &buck18, &voltage ) ) 
            {
                log_printf( &logger, " Voltage : %.3f[V]\r\n\n", voltage );
                Delay_ms ( 1000 );
                Delay_ms ( 1000 );
                Delay_ms ( 1000 );
                Delay_ms ( 1000 );
                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.Buck18

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.