AccelQvar click

Accel&Qvar Click is a compact add-on board for capturing precise acceleration measurements and detecting electric charge variations. This board features the LIS2DUXS12, an ultralow-power accelerometer from STMicroelectronics. Besides low power consumption, it also includes Qvar technology, artificial intelligence, and an anti-aliasing filter. This digital, 3-axis accelerometer has adjustable full scales (±2g to ±16g), output data rates (1.6Hz to 800Hz), and multiple operating modes to serve various applications.

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Click library

• Author : Nenad Filipovic
• Date : Nov 2023.
• Type : I2C/SPI type

Software Support

We provide a library for the AccelQvar 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 AccelQvar Click driver.

Standard key functions :

• accelqvar_cfg_setup Config Object Initialization function.

  void accelqvar_cfg_setup ( accelqvar_cfg_t *cfg );

• accelqvar_init Initialization function.

  err_t accelqvar_init ( accelqvar_t *ctx, accelqvar_cfg_t *cfg );

• accelqvar_default_cfg Click Default Configuration function.

  err_t accelqvar_default_cfg ( accelqvar_t *ctx );

Example key functions :

• accelqvar_get_axes_data This function reads the accelerometer sensor axes data.

  err_t accelqvar_get_axes_data ( accelqvar_t *ctx, accelqvar_axes_t *axes );

• accelqvar_get_qvar_data This function reads the Qvar electrostatic sensor data output.

  err_t accelqvar_get_qvar_data ( accelqvar_t *ctx, float *qvar );

Example Description

This library contains API for the AccelQvar Click driver. The library initializes and defines the I2C and SPI drivers to write and read data from registers and the default configuration for reading the accelerator data and Qvar electrostatic sensor measurement.

The demo application is composed of two sections :

Application Init

The initialization of I2C and SPI module and log UART. After driver initialization, the app sets the default configuration.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    accelqvar_cfg_t accelqvar_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.
    accelqvar_cfg_setup( &accelqvar_cfg );
    ACCELQVAR_MAP_MIKROBUS( accelqvar_cfg, MIKROBUS_1 );
    err_t init_flag = accelqvar_init( &accelqvar, &accelqvar_cfg );
    if ( ( I2C_MASTER_ERROR == init_flag ) || ( SPI_MASTER_ERROR == init_flag ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    Delay_ms ( 100 );

    if ( ACCELQVAR_ERROR == accelqvar_default_cfg ( &accelqvar ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    Delay_ms ( 100 );

    log_info( &logger, " Application Task " );
    log_printf( &logger, "_________________\r\n" );
}

Application Task

This example demonstrates the use of the AccelQvar Click board. Measures and displays acceleration data for the X-axis, Y-axis, and Z-axis [mg] and detects and displays a touch position and the strength of a touch. Results are being sent to the UART Terminal, where you can track their changes.

void application_task ( void )
{
    accelqvar_axes_t acc_axis;
    if ( ACCELQVAR_OK == accelqvar_get_axes_data( &accelqvar, &acc_axis ) )
    {
        log_printf( &logger, " Accel X: %.2f mg\r\n", acc_axis.x );
        log_printf( &logger, " Accel Y: %.2f mg\r\n", acc_axis.y );
        log_printf( &logger, " Accel Z: %.2f mg\r\n", acc_axis.z );
        log_printf( &logger, "_________________\r\n" );
    }

    float qvar = 0;
    if ( ACCELQVAR_OK == accelqvar_get_qvar_data( &accelqvar, &qvar ) )
    {
        if ( abs( qvar ) > ACCELQVAR_THOLD_DETECT_TOUCH )
        {
            uint8_t touch_strength = ( uint8_t ) ( abs( qvar ) / ACCELQVAR_THOLD_SENS );
            log_printf( &logger, " Touch position: " );
            if ( qvar < ACCELQVAR_TOUCH_ZERO )
            {
                log_printf( &logger, " Left\r\n" );
            }
            else
            {
                log_printf( &logger, " Right\r\n " );
            }
            log_printf( &logger, " Strength: " );
            while ( touch_strength )
            {
                log_printf( &logger, "|" );
                touch_strength--;
            }
            log_printf( &logger, "\r\n_________________\r\n" );
            Delay_ms ( 100 );
        }
    }
    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.AccelQvar

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.