Gaussmeter click

Gaussmeter click is a device that is used for measuring the magnetic field in X, Y and Z axes. This Click board™ features the MLX90393, a micropower magnetometer based on the proprietary Triaxis® technology, from Melexis.>

click Product page

Click library

• Author : MikroE Team
• Date : Feb 2020.
• Type : I2C/SPI type

Software Support

We provide a library for the Gaussmeter 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 Gaussmeter Click driver.

Standard key functions :

• Config Object Initialization function.

  void gaussmeter_cfg_setup ( gaussmeter_cfg_t *cfg );

• Initialization function.

  GAUSSMETER_RETVAL gaussmeter_init ( gaussmeter_t ctx, gaussmeter_cfg_t cfg );

• Click Default Configuration function.

  void gaussmeter_default_cfg ( gaussmeter_t *ctx );

Example key functions :

• This function writes 16-bit data to the specified register address.

  uint8_t gaussmeter_write_reg ( gaussmeter_t *ctx, uint8_t reg_addr, uint16_t transfer_data );

• This function reads the temperature and axis data from the chip.

  uint8_t gaussmeter_get_data( gaussmeter_t ctx, float output_data );

• This function reads the digital input signal from the INT pin.

  uint8_t gaussmeter_digital_read_int ( gaussmeter_t *ctx );

Examples Description

This example showcases how to configure and use the Gaussmeter click. This click measures magnetic fields around the device using a 3 axis measurement system. Alongside the magnetometer, the click contains an integrated temperature sensor which provides data for the thermal compensation.

The demo application is composed of two sections :

Application Init

This function initializes and configures the click and logger modules. Additional configuring is done in the default_cfg(...) function.

void application_init ( )
{
    log_cfg_t log_cfg;
    gaussmeter_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_info( &logger, "---- Application Init ----" );

    //  Click initialization.

    gaussmeter_cfg_setup( &cfg );
    GAUSSMETER_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    gaussmeter_init( &gaussmeter, &cfg );
    Delay_ms ( 100 );
    gaussmeter_default_cfg( &gaussmeter );
    Delay_ms ( 500 );
}

Application Task

This function reads data from the magnetometer and the temperature sensor and displays that data using the UART console every 400 milliseconds.

void application_task ( )
{
    float temp_buf[ 4 ] = { 0 };
    uint8_t error_bit;
    uint8_t axis_check;
    uint8_t cnt;

    error_bit = gaussmeter_get_data( &gaussmeter, temp_buf );

    if ( !error_bit )
    {
        axis_check = 1;
        buf_idx = 0;
    }

    for ( cnt = 0; cnt < 4; cnt++ )
    {
        switch ( gaussmeter.aux.command_byte_low & axis_check )
        {
            case 1:
            {
                log_printf( &logger, " * Temperature: %.2f C\r\n", temp_buf[ buf_idx++ ] );
                break;
            }
            case 2:
            {
                log_printf( &logger, " * X-axis: %.2f microT\r\n", temp_buf[ buf_idx++ ] );
                break;
            }
            case 4:
            {
                log_printf( &logger, " * Y-axis: %.2f microT\r\n", temp_buf[ buf_idx++ ] );
                break;
            }
            case 8:
            {
                log_printf( &logger, " * Z-axis: %.2f microT\r\n", temp_buf[ buf_idx++ ] );
            }
        }
        axis_check <<= 1;
    }
    log_printf( &logger, "----------------------------------\r\n" );
    Delay_ms ( 400 );
} 

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.Gaussmeter

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.