dfilter_avg.h

/*
 * Copyright (c) 2012, Regents of the University of California
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * - Neither the name of the University of California, Berkeley nor the names
 *   of its contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 *
 *
 * Averaging filter using a circular buffer
 *
 * by Andrew Pullin
 *
 * v.0.1
 */

#ifndef __DFILTER_AVG_H
#define __DFILTER_AVG_H


typedef struct {
    unsigned int windowLen;
    unsigned int index;
    int* data;
    long accum;
} dfilterAvgInt_t;

// Creates a filter and returns a point.
// Caller should check for NULL returns.
void dfilterAvgCreate(dfilterAvgInt_t*, unsigned int);

// Add a value to the circular buffer, incrementing index
void dfilterAvgUpdate(dfilterAvgInt_t*, int);

// Calculate and return average value;
int dfilterAvgCalc(dfilterAvgInt_t*);

//Zero all values in the filter
void dfilterZero(dfilterAvgInt_t* filt);

#endif // __DFILTER_AVG_H