filter.h File Reference

Filter header file. More...

#include "stdint.h"

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Macros
#define	MAX_INT   32767
	Maximum value of integers.

Functions
int16_t	calculateEMA (uint16_t currentSample, uint16_t previousEMA, uint8_t alphaExponent)
	Exponential Moving Average (EMA) calculation algorithm.

Detailed Description

Filter header file.

This file contains defines, typedefs and prototypes for the filter implementation.

Author

Nexperia: http://www.nexperia.com

Support Page

For additional support, visit: https://www.nexperia.com/support

Author

Aanas Sayed

Date

2024/03/08

Definition in file filter.h.

Macro Definition Documentation

MAX_INT

#define MAX_INT   32767

Maximum value of integers.

Definition at line 29 of file filter.h.

Function Documentation

calculateEMA()

int16_t calculateEMA	(	uint16_t	currentSample,
		uint16_t	previousEMA,
		uint8_t	alphaExponent )

Exponential Moving Average (EMA) calculation algorithm.

Calculates EMA from current sample, previous EMA and alpha.

Parameters

currentSample	Current measured sampled.
previousEMA	Previously calculated EMA.
alphaExponent	Used to drive alpha where alpha = 1 / (2 ^ alphaExponent).

Returns

Returns the calculated Exponential Moving Average (EMA) as a 16-bit signed integer.

Definition at line 34 of file filter.cpp.

{
     if (currentSample > MAX_INT)
     {
          currentSample = MAX_INT;
     }
     if (previousEMA > MAX_INT)
     {
          previousEMA = MAX_INT;
     }
 
     int16_t newEMA = (int16_t)previousEMA;
     newEMA += ((int16_t)currentSample - (int16_t)previousEMA) >> alphaExponent;
 
     if (newEMA < 0)
     {
          newEMA = 0;
     }
 
     return newEMA;
}

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