Library Description

The library performs a control of the Altitude 3 Click board. This library can read a calibration data from OTP sensor, also a temperature and pressure results of AD conversion. The all converted results can be calculated to standard units, and depending on the temperature and pressure data the library can calculate altitude. For more details check documentation.

Key functions:

• T_ALTITUDE3_RETVAL altitude3_measurementMode( uint16_t modeCmd ) - Function sends a command which selects a measurement mode and data reading order.
• void altitude3_init( T_altitude3_param *s ) - Function sends a command to read calibration data from OTP sensor and other initialization data, which is necessary for calculations.
• T_ALTITUDE3_RETVAL altitude3_getData( uint8_t read_order, int8_t *temperature, uint16_t *pressure, int16_t *altitude ) - Function performs a calibration data reading, only once, and then reads a temperature and pressure data and calculates these values to standard units. Also calculates the altitude depending on the temperature and pressure data.

Examples description

The application is composed of the three sections :

• System Initialization - Initializes peripherals and pins.
• Application Initialization - Initializes I2C interface and performs a SW Reset of the device.
• Application Task - (code snippet) - Selects the desired measurement mode and data reading order, and after that calculates the temperature, pressure and altitude data to standard units and shows results to uart terminal.

void applicationTask()
{
    response = altitude3_measurementMode( _ALTITUDE3_NORMAL_T_FIRST );

    response = altitude3_getData( response, &_temperature, &_pressure, &_altitude );
    
    if (response == _ALTITUDE3_OK)
    {
        ShortToStr( _temperature, text );
        mikrobus_logWrite( "Temperature is : ", _LOG_TEXT );
        mikrobus_logWrite( text, _LOG_TEXT );
        logUnit();

        WordToStr( _pressure, text );
        mikrobus_logWrite( "Pressure is : ", _LOG_TEXT );
        mikrobus_logWrite( text, _LOG_TEXT );
        mikrobus_logWrite( " mbar[hPa]", _LOG_LINE );
    
        IntToStr( _altitude, text );
        mikrobus_logWrite( "Altitude is : ", _LOG_TEXT );
        mikrobus_logWrite( text, _LOG_TEXT );
        mikrobus_logWrite( " m", _LOG_LINE );
        mikrobus_logWrite( "", _LOG_LINE );

        Delay_ms( 400 );
    }
}

Additional Functions :

• logUnit - Shows Celsius degrees symbol to uart terminal.

Other mikroE Libraries used in the example:

• Conversions
• I2C
• UART

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 clickor 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.