ustd::sensorprocessor Class Reference

muwerk sensorprocessor class More...

#include <sensors.h>

Public Member Functions
	sensorprocessor (unsigned int smoothInterval=5, int unsigned pollTimeSec=60, double eps=0.1)
bool	filter (double *pvalue)
bool	filter (long *plvalue)
void	reset ()
void	update (unsigned int _smoothInterval=5, int unsigned _pollTimeSec=60, double _eps=0.1)

Detailed Description

muwerk sensorprocessor class

sensorprocessor implements an exponential filter that smoothens and throttles raw sensor data.

It can be configured by:

• size of smoothing interval: larger intervals generate larger averaging and slower response to change
• minimum change eps required to generate a new sensor reading, in order to ignore small fluctuations
• a time-interval in seconds that generates a new sensor reading regardless of change.

This library requires the ustd library (for timeDiff) and requires a platform define.

Example:

void setup() {
    // generate a filter that exponentially averages over 10 values,
    // generates a new reading at least every 3600sec (even on no
    // change)
    // and generates a new reading every time, the filter value changes
    // for more than 0.1
    ustd::sensorprocessor mySensor(10,3600,0.1)
}
 
void loop() {
    double rawValue=ReadMyRawSensor();
    double filtered=rawValue;
    if mySensor.filter(&filtered) {
        printf("We got a new, filtered reading: %f\n", filtered);
    } else {
        // no valid new reading, do nothing.
    }
}

Constructor & Destructor Documentation

sensorprocessor()

ustd::sensorprocessor::sensorprocessor ( unsigned int  smoothInterval = 5, int unsigned  pollTimeSec = 60, double  eps = 0.1  )

inline

Creates a new sensorprocessor

Parameters

smoothInterval	The size of the interval of sensor value history that are being averaged using exponential decay.
pollTimeSec	If this is !=0, a valid sensor reading is generated at least every pollTimeSec, regardless of value changes.
eps	The minimal change required for the smoothed sensor value in order to create a new valid reading. Useful for supressing small fluctuations.

Member Function Documentation

filter() [1/2]

bool ustd::sensorprocessor::filter ( double *  pvalue )

inline

The sensorprocessor filter function. (double float version)

Parameters

*pvalue

the current raw sensor reading. The filter function uses exponential smoothing to filter the value and, if a valid new value is available, changes *pvalue.

Returns

on true, *pvalue contains a new, smoothed valid sensor reading. A new reading is generated by either pollTimeSec (!=0) seconds have been passed, or the smoothed value has changed more than espilon eps. A return value of false indicates, that no new sensor reading is available.

filter() [2/2]

bool ustd::sensorprocessor::filter ( long *  plvalue )

inline

The sensorprocessor filter function. (long integer version)

Parameters

*plvalue

the current raw sensor reading. The filter function uses exponential smoothing to filter the value and, if a valid new value is available, changes *plvalue.

Returns

on true, *plvalue contains a new, smoothed valid sensor reading. A new reading is generated by either pollTimeSec (!=0) seconds have been passed, or the smoothed value has changed more than espilon eps. A return value of false indicates, that no new sensor reading is available.

reset()

void ustd::sensorprocessor::reset ( )

inline

Delete the filter history

update()

void ustd::sensorprocessor::update ( unsigned int  _smoothInterval = 5, int unsigned  _pollTimeSec = 60, double  _eps = 0.1  )

inline

Update filter parameters and reset.

Note: this is equivalent of recreating a new instance.

Parameters

_smoothInterval	The size of the interval of sensor value history that are being averaged using exponential decay.
_pollTimeSec	If this is !=0, a valid sensor reading is generated at least every pollTimeSec, regardless of value changes.
_eps	The minimal change required for the smoothed sensor value in order to create a new valid reading. Useful for supressing small fluctuations.

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The documentation for this class was generated from the following file:

• sensors.h