FiltersTest.nxc

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/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -*- */
/*
    FiltersTest.nxc
    Copyright (C) 2008 Naba Kumar   <naba@gnome.org>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
#include "Sampler.nxc"
#include "LowPassFilter.nxc"
#include "HighPassFilter.nxc"

#define LIGHT_SENSOR IN_3
#define LIGHT_SENSOR_SAMPLING_PERIOD 36 /* degrees */
#define LIGHT_SENSOR_SAMPLING_RATE   30 /* samples per cycle (1080 degrees) */

task
main ()
{
    int t = 0;
    int x1 = 0, x2 = 0;
    int max = 0;
    SamplerContext sampler;
    HighPassFilterContext highPass;
    LowPassFilterContext lowPass;

    SetSensorLight(LIGHT_SENSOR);
    ClearScreen();
    ResetAllTachoCounts(OUT_B);
    SamplerInit(sampler, 0, LIGHT_SENSOR_SAMPLING_PERIOD);
    HighPassFilterInit(highPass, 3 /* 0.5Hz * 2 * PI */, LIGHT_SENSOR_SAMPLING_RATE);
    LowPassFilterInit(lowPass, 24 /* 4Hz * 2 * PI */, LIGHT_SENSOR_SAMPLING_RATE);

    OnFwd(OUT_B, 100);
    while (1)
    {
        int tachoCount = GetOutput(OUT_B, TachoCount);
        int lightSense = Sensor(LIGHT_SENSOR);

        do {
            int lightSenseSample = SamplerGet(sampler, tachoCount, lightSense);
            if (lightSenseSample < 0)
                break;
            int highPassOut = HighPassFilter(highPass, lightSenseSample);
            int lowPassOut = LowPassFilter(lowPass, highPassOut);

            /* Plot both intput and output samplings */
            //LineOut(t, 48, t, 48 + lightSense - 50, false);
            LineOut(t,  16, t, 16 + lowPassOut, false);
            t++;
            if (t >= 60)
            {
               ClearScreen();
               t = 0;
            }
        } while (sampler.hasMore);
    }
}