File content as of revision 0:332104904b69:

#include "MovingAverage.h"

MovingAverage::MovingAverage(int number_of_samples) {
    _started = 0;
    _average = 0.0;
    _num_samples = number_of_samples;
}

float MovingAverage::filter(float value) {
    // If this filter has already started, means we have other samples
    if (_started) {
        float dropping_value;
        if (_samples.get(&dropping_value) == 0) { // if no errors
            // if value == dropping_value, average is kept the same
            _average = _average + ((value - dropping_value) / _num_samples);
            _samples.put(value);
        }
    }
    // If we are starting now, this sample is all we have
    else {
        // fills the buffer with the initial value
        for (int i=0; i < _num_samples; i++) _samples.put(value);
        _started = 1;
        _average = value; // Average is the initial value.
    }
    return _average;
}



// FIFO HELPER CLASS

_ma_fifo::_ma_fifo() {
    head = 0;
    tail = 0;
}
int _ma_fifo::available() {
    return (_MA_FIFO_SIZE + this->head - this->tail) % _MA_FIFO_SIZE;
}
int _ma_fifo::free() {
    return (_MA_FIFO_SIZE - 1 - available());
}
int _ma_fifo::put(float data) {
    int next;
    // check if FIFO has room
    next = (head + 1) % _MA_FIFO_SIZE;
    if (next == tail) return 1; // fifo full

    buffer[head] = data;
    head = next;
    return 0;
}
int _ma_fifo::get(float * data) {
    int next;
    // check if FIFO has data
    if (head == tail) return 1; // FIFO empty

    next = (tail + 1) % _MA_FIFO_SIZE;
    *data = buffer[tail];
    tail = next;
    return 0;
}