TouchClamp Click

TouchClamp Click is a mikroBUS™ add-on board with NXP’s MPR121 proximity capacitive touch sensor controller. It has seven plated holes for clamps which can be used to connect any – literally any – conductive object in order to use it as an input button to send an interrupt to the target board MCU.

Click Product page

Click library

• Author : Nenad Filipovic
• Date : Dec 2019.
• Type : I2C type

Software Support

We provide a library for the TouchClamp 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 form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for TouchClamp Click driver.

Standard key functions :

• Config Object Initialization function.

  void touchclamp_cfg_setup ( touchclamp_cfg_t *cfg );

• Initialization function.

  TOUCHCLAMP_RETVAL touchclamp_init ( touchclamp_t ctx, touchclamp_cfg_t cfg );

• Click Default Configuration function.

  void touchclamp_default_cfg ( touchclamp_t *ctx );

Example key functions :

• Get touch data function.

  uint16_t touchclamp_get_touch_data ( touchclamp_t *ctx );

Examples Description

This demo-app shows the touch position using TouchClamp Click.

The demo application is composed of two sections :

Application Init

Configuring clicks and log objects. Setting the Click in the default configuration.

void application_init ( void )
{
    log_cfg_t log_cfg;
    touchclamp_cfg_t cfg;

    /** 
     * 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_printf( &logger, " Application Init \r\n" );

    //  Click initialization.

    touchclamp_cfg_setup( &cfg );
    TOUCHCLAMP_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    touchclamp_init( &touchclamp, &cfg );
    Delay_ms ( 100 );

    touchclamp_soft_reset( &touchclamp );
    Delay_ms ( 100 );

    touchclamp_default_cfg( &touchclamp );
    Delay_ms ( 100 );

    touch_data_old = TOUCHCLAMP_NO_TOUCH;

    log_printf( &logger, "-------------------\r\n" );
    log_printf( &logger, " Touch Clamp Click \r\n" );
    log_printf( &logger, "-------------------\r\n" );
}

Application Task

Detect and dispay touch position when the Click is triggered.

void application_task ( void )
{
    touch_data = touchclamp_get_touch_data( &touchclamp );

    if ( touch_data_old != touch_data )
    {
        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_H )
            log_printf( &logger, "  - - - - - - - H\r\n" );

        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_G )
            log_printf( &logger, "  - - - - - - G -\r\n" );

        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_F )
            log_printf( &logger, "  - - - - - F - -\r\n" );

        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_E )                       
            log_printf( &logger, "  - - - - E - - -\r\n" );

        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_D )                       
            log_printf( &logger, "  - - - D - - - -\r\n" );

        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_C )                       
            log_printf( &logger, "  - - C - - - - -\r\n" );

        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_B )                       
            log_printf( &logger, "  - B - - - - - -\r\n" );

        if ( touch_data == TOUCHCLAMP_TOUCH_POSITION_A )                       
            log_printf( &logger, "  A - - - - - - -\r\n" );

        touch_data_old = touch_data;
    }
}  

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.TouchClamp

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.