Pressure Click

Pressure Click is a compact and easy solution for adding pressure measurement to your design. It features LPS331AP digital output pressure sensor.

Click Product page

Click library

• Author : Nemanja Medakovic
• Date : Nov 2019.
• Type : I2C/SPI type

Software Support

We provide a library for the Pressure 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 Pressure Click driver.

Standard key functions :

• Configuration Object Setup function.

  void pressure_cfg_setup( pressure_cfg_t *cfg );

• Click Initialization function.

  pressure_err_t pressure_init( pressure_t ctx, pressure_cfg_t cfg );

• Click Default Configuration function.

  void pressure_default_cfg( pressure_t *ctx );

Example key functions :

• Generic Single Write function.

  pressure_err_t pressure_generic_single_write( pressure_t *ctx, uint8_t reg_addr, uint8_t data_in );

• Generic Multiple Read function.

  pressure_err_t pressure_generic_multiple_read( pressure_t ctx, uint8_t reg_addr, uint8_t data_out, uint8_t n_data );

• Pressure Get function.

  float pressure_get_pressure( pressure_t *ctx );

Examples Description

This is a example which demonstrates the use of Pressure Click board. Measured pressure and temperature data from the LPS331AP sensor on Pressure Click.

The demo application is composed of two sections :

Application Init

Initializes I2C/SPI serial interface and puts a device to the initial state. Also initializes UART console module for results logging.

void application_init( void )
{
    pressure_cfg_t pressure_cfg;
    log_cfg_t console_cfg;

    //  Click initialization.
    pressure_cfg_setup( &pressure_cfg );
    PRESSURE_MAP_MIKROBUS( pressure_cfg, MIKROBUS_1 );
    pressure_init( &pressure, &pressure_cfg );
    pressure_sw_reset( &pressure );
    pressure_default_cfg( &pressure );

    /** 
     * 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( console_cfg );
    log_init( &console, &console_cfg );
    log_write( &console, "***  Pressure initialization done  ***",
               LOG_FORMAT_LINE );
    log_write( &console, "**************************************",
               LOG_FORMAT_LINE );
}

Application Task

Reads the pressure and temperature results in standard units when measurement was done and sends results to the console (usb uart terminal). Repeats operation every 500ms.

void application_task( void )
{
    uint8_t status;
    float press;
    float temp;

    status = pressure_get_status( &pressure, PRESSURE_FLAG_MASK_P_DATA_RDY |
                                             PRESSURE_FLAG_MASK_T_DATA_RDY );

    while (!status)
    {
        status = pressure_get_status( &pressure, PRESSURE_FLAG_MASK_P_DATA_RDY |
                                                 PRESSURE_FLAG_MASK_T_DATA_RDY );
    }

    press = pressure_get_pressure( &pressure );
    temp = pressure_get_temperature( &pressure );

    log_printf( &console, "** Pressure is %.2f mbar\r\n", press );
    log_printf( &console, "** Temperature is %.2f ", temp );
    log_write( &console, deg_cels, LOG_FORMAT_LINE );
    log_write( &console, "**************************************",
               LOG_FORMAT_LINE );

    Delay_ms ( 500 );
}

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.Pressure

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.