File content as of revision 0:0a76ae27065b:

/*
mbed touchpad & accelerometer experiments.

CPV, 14/09/2009
*/


#include <string.h>
#include "filters.h"


void FilterBoxF::initialise(unsigned int size)
{
  m_size = size;
  if (m_size>FILTER_MAX_SIZE) m_size = FILTER_MAX_SIZE;
  memset(m_history,0,sizeof(float)*FILTER_MAX_SIZE);
  m_index = 0;
  m_out = 0;
}


float FilterBoxF::tick(float in)
{
  m_history[m_index] = in;
  m_index += 1;
  if (m_index>=m_size) m_index = 0;

  float sum = 0;
  for (int i=0; i<m_size; i++)
  {
    sum += m_history[i];
  }
  m_out = sum/m_size;
  return m_out;
}

//=================================

void FilterBoxI::initialise(unsigned int size)
{
  m_size = size;
  if (m_size>FILTER_MAX_SIZE) m_size = FILTER_MAX_SIZE;
  memset(m_history,0,sizeof(int)*FILTER_MAX_SIZE);
  m_index = 0;
  m_out = 0;
}


int FilterBoxI::tick(int in)
{
  m_history[m_index] = in;
  m_index += 1;
  if (m_index>=m_size) m_index = 0;

  int sum = 0;
  for (int i=0; i<m_size; i++)
  {
    sum += m_history[i];
  }
  m_out = sum/m_size;
  return m_out;
}

//=================================

void FilterIirI::initialise(int tau, int limit)
{
  m_tau = tau;
  m_limit = limit;
  m_remainder = 0;
  m_out = 0;
}


int FilterIirI::tick(int in)
{
  int temp = in - m_out + m_remainder;
  m_remainder = temp % m_tau;
  m_out += temp / m_tau;
  if (m_out>m_limit) m_out = m_limit;
  if (m_out<-m_limit) m_out = -m_limit;
  return m_out;
}