ML8953AccelerometerImplementation.java

package com.buglabs.bug.module.lcd;

import java.io.IOException;

import com.buglabs.bug.accelerometer.pub.AccelerometerSample;
import com.buglabs.bug.accelerometer.pub.IAccelerometerSampleProvider;
import com.buglabs.bug.module.lcd.pub.IML8953Accelerometer;

/**
 * Handles fetching parsing, passing back values from sysfs relating to the
 * ML8953Accelerometer.
 * 
 * @author jconnolly
 * 
 */
public class ML8953AccelerometerImplementation implements IML8953Accelerometer,
		IAccelerometerSampleProvider {

	private ML8953Device device;

	public ML8953AccelerometerImplementation() {
		device = ML8953Device.getInstance();
	}

	public short readX() throws IOException {
		String position = device.getPosition();
		position = position.substring(position.indexOf('(') + 1,
				position.indexOf(','));
		return Short.parseShort(position.trim());
	}

	public short readY() throws IOException {
		String position = device.getPosition().trim();
		position = position.substring(position.indexOf(',') + 1);
		position = position.substring(0, position.indexOf(','));
		return Short.parseShort(position.trim());
	}

	public short readZ() throws IOException {
		String position = device.getPosition();
		position = position.substring(position.lastIndexOf(',') + 1,
				position.indexOf(')'));
		return Short.parseShort(position.trim());
	}

	private float convert2gs(final short raw) {
		return raw / 1000F;
	}

	//
	// Accelerometer Sample Provider
	//

	// TODO: should we be doing the -1 on Y or is something else bassackwards?
	public AccelerometerSample readSample() throws IOException {
		return new AccelerometerSample(
				convert2gs(readX()),
				convert2gs(readY())	* -1F, // is this necessary?
				convert2gs(readZ()));
	}

}