pressure_utl.h File Reference

Pressure computing utility function. More...

#include <stdint.h>

Go to the source code of this file.

Functions
int16_t	convertSensor2Pressure (uint32_t sensorValue)
	Convert the analog value from sensor to a pressure value. More...
void	resetFilteredRawPressure ()
	Reset the value of void filteredRawPressure to 0. More...

Detailed Description

Pressure computing utility function.

Copyright

Copyright (c) 2020 Makers For Life

Author

Makers For Life

Definition in file pressure_utl.h.

Function Documentation

convertSensor2Pressure()

int16_t convertSensor2Pressure

(

uint32_t

sensorValue

)

Convert the analog value from sensor to a pressure value.

Parameters

sensorValue

Value read from the analog input connected to the sensor

Returns

The pressure in mmH2O

Definition at line 51 of file pressure_utl.cpp.

                                                     {
    int32_t rawPressure = static_cast<int32_t>(sensorValue);
    int32_t delta = rawPressure - filteredRawPressure;
 
    // Adjust delta so that the division result will be rounded away from zero.
    // This is needed to guaranty that filteredRawPressure will reach
    // rawPressure when it is constant.
    int32_t rounding = RAW_PRESSURE_FILTER_DIVIDER - 1;
    delta += (delta > 0) ? rounding : -rounding;
    filteredRawPressure += delta / RAW_PRESSURE_FILTER_DIVIDER;
 
    int16_t scaledRawPressure =
        filteredRawPressure * RAW_PRESSURE_TO_MMH20_NUM / RAW_PRESSURE_TO_MMH20_DEN;
    return scaledRawPressure - RAW_PRESSURE_TO_MMH20_CONSTANT;
}

resetFilteredRawPressure()

void resetFilteredRawPressure

(

)

Reset the value of void filteredRawPressure to 0.

Note

Mainly for testing purpose

Definition at line 68 of file pressure_utl.cpp.

{ filteredRawPressure = 0; }