/*
This file is part of JOP, the Java Optimized Processor
see <http://www.jopdesign.com/>
Copyright (C) 2007, Peter Hilber and Alexander Dejaco
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 3 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, see <http://www.gnu.org/licenses/>.
*/
package lego.lib;
import com.jopdesign.sys.*;
/**
* Provides access to sensor ADC values (sensors S0-S2).
* @author Peter Hilber (peter.hilber@student.tuwien.ac.at)
*
*/
public class Sensors
{
public static final int IO_SENSORS = Const.IO_LEGO;
/**
* XXX
*/
public static final int MIN_VALUE = 135;
/**
* XXX
*/
public static final int MAX_VALUE = 361;
public static final int VALUE_RANGE = MAX_VALUE - MIN_VALUE;
/**
* percentage calculation factor * 2**20
*/
protected static final int PERCENTAGE_CALC_FACTOR = 463972;
protected static final int PERCENTAGE_CALC_FACTOR_SHIFT = 20;
protected static int value = 0;
protected static final int[] OFFSET_SENSOR = { 0, 9, 2*9 };
protected static final int MASK_SENSOR = 0x1FF;
/**
* Reads all sensor values into a buffer during the same cycle.
* The buffered values may be read using {@linkplain #getBufferedSensor(int)}.
*/
public static void synchronizedReadSensors()
{
value = Native.rd(IO_SENSORS);
}
/**
* Return the value read from the respective sensor.
* @param index 0-2.
* @return 9 bit ADC value. Expected value range is {@linkplain #MIN_VALUE}-{@linkplain #MAX_VALUE}.
*/
public static int readSensor(int index)
{
return (Native.rd(IO_SENSORS) >> OFFSET_SENSOR[index]) & MASK_SENSOR;
}
/**
* Return the value read from the respective sensor as a percentage value.
* @param index 0-2.
* @return 0-100.
* Values smaller than {@linkplain #MIN_VALUE} or greater than
* {@linkplain #MAX_VALUE} are cut.
*/
public static int readSensorValueAsPercentage(int index)
{
//return (Math.min(Math.max(readSensor(index)-MIN_VALUE, 0), MAX_VALUE) * 100) / VALUE_RANGE;
return (Math.min(Math.max(readSensor(index)-MIN_VALUE, 0), MAX_VALUE) * PERCENTAGE_CALC_FACTOR) >> PERCENTAGE_CALC_FACTOR_SHIFT;
}
/**
* Returns value read by {@linkplain #synchronizedReadSensors()}
* @param index 0-2.
* @return 9 bit ADC value. Expected value range is {@linkplain #MIN_VALUE}-{@linkplain #MAX_VALUE}.
*/
public static int getBufferedSensor(int index)
{
return (value >> OFFSET_SENSOR[index]) & MASK_SENSOR;
}
}