Diff Press 4 Click

Diff Press 4 Click is a compact add-on board that can measure differential pressure. This board features the SM9336-BCE-S-250-000, a digital pressure and altimeter sensor module from TE Connectivity. The SM9336-BCE-S-250-000 has a configurable host interface that supports I2C serial communication and measures pressure in a wide range with an accuracy of 3%. It comes as calibrated and temperature-compensated with high reliability/long-term stability. It operates in a compensated temperature range of -20°C to 85°C, ensuring stable operation under extreme conditions.

Click Product page

Click library

• Author : Nenad Filipovic
• Date : Aug 2023.
• Type : I2C type

Software Support

We provide a library for the Diff Press 4 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 Diff Press 4 Click driver.

Standard key functions :

• diffpress4_cfg_setup Config Object Initialization function.

  void diffpress4_cfg_setup ( diffpress4_cfg_t *cfg );

• diffpress4_init Initialization function.

  err_t diffpress4_init ( diffpress4_t *ctx, diffpress4_cfg_t *cfg );

Example key functions :

• diffpress4_get_measurement_data Diff Press 4 gets the raw data function.

  err_t diffpress4_get_measurement_data ( diffpress4_t *ctx, float *diff_press, float *temperature );

• diffpress4_get_status Diff Press 4 get status function.

  err_t diffpress4_get_status ( diffpress4_t *ctx, diffpress4_status_t *status );

• diffpress4_get_raw_data Diff Press 4 gets the raw data function.

  err_t diffpress4_get_raw_data ( diffpress4_t *ctx, int16_t *temp_data, int16_t *press_data );

Example Description

This example demonstrates the use of Diff Press 4 Click board™ by reading and displaying the differential pressure and sensor temperature measurements.

The demo application is composed of two sections :

Application Init

The initialization of I2C 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. */
    diffpress4_cfg_t diffpress4_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.
    diffpress4_cfg_setup( &diffpress4_cfg );
    DIFFPRESS4_MAP_MIKROBUS( diffpress4_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == diffpress4_init( &diffpress4, &diffpress4_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
    log_printf( &logger, " _______________________ \r\n" );
    Delay_ms ( 100 );
}

Application Task

The demo application reads and displays the Differential Pressure [Pa] and sensor Temperature [degree Celsius] data measurements. Results are being sent to the UART Terminal, where you can track their changes.

void application_task ( void ) 
{
    static float diff_press = 0, temperature = 0;
    diffpress4_status_t status;
    diffpress4_get_status( &diffpress4, &status );
    if ( ( DIFFPRESS4_OK == diffpress4_get_measurement_data( &diffpress4, &diff_press, &temperature ) ) &&
         ( DIFFPRESS4_STATUS_DSP_S_UPDATED == status.dsp_s_up ) && 
         ( DIFFPRESS4_STATUS_DSP_T_UPDATED == status.dsp_t_up ) )
    {
        log_printf( &logger, " Diff Pressure : %.2f [Pa] \r\n", diff_press );
        log_printf( &logger, " Temperature   : %.2f [degC] \r\n", temperature );
        log_printf( &logger, " _______________________ \r\n" );
        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.DiffPress4

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.