digipot

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DIGI POT click

DIGIPOT Click is an accessory board in mikroBUS form factor. It features a single-channel digital potentiometer MCP4161 with 8-bit resolution (256 wiper steps) and industry-standard SPI serial interface.

click Product page

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Click library

• Author : Stefan Ilic
• Date : Jun 2021.
• Type : SPI type

Software Support

We provide a library for the DigiPot 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 DigiPot Click driver.

Standard key functions :

• digipot_cfg_setup Config Object Initialization function.

void digipot_cfg_setup ( digipot_cfg_t *cfg );

• digipot_init Initialization function.

err_t digipot_init ( digipot_t *ctx, digipot_cfg_t *cfg );

Example key functions :

• digipot_set_wiper_positions The function sets 8-bit wiper positions data.

void digipot_set_wiper_positions ( digipot_t *ctx, uint8_t wiper_pos );

• digipot_convert_output The function convert 10-bit ADC value to volatage reference.

float digipot_convert_output ( uint16_t adc_val, float v_ref );

Example Description

The demo application changes the resistance using DIGIPOT Click.

The demo application is composed of two sections :

Application Init

Initializes SPI and LOG modules.

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    digipot_cfg_t digipot_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.

    digipot_cfg_setup( &digipot_cfg );
    DIGIPOT_MAP_MIKROBUS( digipot_cfg, MIKROBUS_1 );
    err_t init_flag  = digipot_init( &digipot, &digipot_cfg );
    if ( SPI_MASTER_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    log_printf( &logger, "----------------\r\n" );
    log_printf( &logger, " DIGI POT Click\r\n" );
    log_printf( &logger, "----------------\r\n" );
}

Application Task

This is an example which demonstrates the use of DIGI POT Click board. Increments the wiper position by 10 positions every 5 seconds.

void application_task ( void ) {
    for ( uint16_t n_cnt = 127; n_cnt < 255; n_cnt += 10 ) {
        wiper_pos = ( uint8_t ) n_cnt;
        digipot_set_wiper_positions( &digipot, wiper_pos );
        Delay_ms( 5000 );
    }
}

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.DigiPot

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. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.

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