IRSeekerV2.java

package lejos.nxt.addon;

import lejos.nxt.I2CPort;
import lejos.nxt.I2CSensor;

public class IRSeekerV2
{
	public static enum Mode {
		AC, DC
	};

	public static final byte	address	= 0x08;
	byte[]						buf		= new byte[1];
	public static final	float	noAngle = Float.NaN;

	private Mode				mode;

	/**
	 * Set the mode of the sensor
	 */
	public void setMode(Mode mode)
	{
		this.mode = mode;
	}

	public IRSeekerV2(I2CPort port, Mode mode)
	{
		super(port, I2CPort.STANDARD_MODE);
		setMode(mode);
		setAddress(address);
	}

	/**
	 * Returns the direction of the target (1 to 9) or 0 if no target.
	 * 
	 * @return direction
	 */
	public int getDirection()
	{
		int register = 0;
		if(mode == Mode.AC)
		{
			register = 0x49;
		}
		else if(mode == Mode.DC)
		{
			register = 0x42;
		}
		int ret = getData(register, buf, 1);
		if(ret != 0)
			return -1;
		return (0xFF & buf[0]);
	}

	/**
	 * Returns the angle of the target (-180 to 180) or NaN.
	 * 
	 * @return direction
	 */
	public float getAngle(boolean blocking)
	{
		while(true)
		{
			int dir = getDirection();
			if(dir != 0)
				return (dir - 5) * 30;
			else if(dir == 0 && !blocking)
				return Float.NaN;
		}
	}
	public float getAngle()
	{
		return getAngle(false);
	}

	public boolean hasDirection()
	{
		return getDirection() != 0;
	}

	/**
	 * Returns value of sensor 1 - 5.
	 * 
	 * @param id
	 *            The id of the sensor to read
	 * @return sensor value (0 to 255).
	 */
	public int getSensorValue(int id)
	{
		int register = 0;
		if(mode == Mode.AC)
		{
			register = 0x4A;
		}
		else if(mode == Mode.DC)
		{
			register = 0x43;
		}
		if(id < 1 || id > 5)
			throw new IllegalArgumentException(
					"The argument 'id' must be between 1 and 5");
		int ret = getData(register + (id - 1), buf, 1);
		if(ret != 0)
			return -1;
		return (0xFF & buf[0]);
	}

	/**
	 * Gets the values of each sensor, returning them in an array.
	 * 
	 * @return Array of sensor values (0 to 255).
	 */
	public int[] getSensorValues()
	{
		int[] values = new int[5];
		for(int i = 0; i < 5; i++)
		{
			values[i] = getSensorValue(i + 1);
		}
		return values;
	}

	/**
	 * Returns the average sensor reading (DC Only)
	 * 
	 * @return sensor value (0 to 255).
	 */
	public int getAverage(int id)
	{
		if(mode == Mode.DC)
		{
			if(id <= 0 || id > 5)
				return -1;
			int ret = getData(0x48, buf, 1);
			if(ret != 0)
				return -1;
			return (0xFF & buf[0]);
		}
		else
		{
			return -1;
		}
	}

	/**
	 * Returns a string representation of the strengths
	 */
	public String toString()
	{
		return "(" + getSensorValue(1) + "," + getSensorValue(2) + ","
				+ getSensorValue(3) + "," + getSensorValue(4) + ","
				+ getSensorValue(5) + ")";
	}
}