| 1 | package org.usfirst.frc.team3501.robot.utils; |
| 2 | |
| 3 | import java.util.TimerTask; |
| 4 | import edu.wpi.first.wpilibj.I2C; |
| 5 | import edu.wpi.first.wpilibj.Timer; |
| 6 | import edu.wpi.first.wpilibj.I2C.Port; |
| 7 | import edu.wpi.first.wpilibj.PIDSource; |
| 8 | import edu.wpi.first.wpilibj.PIDSourceType; |
| 9 | |
| 10 | public class Lidar implements PIDSource { |
| 11 | private I2C i2c; |
| 12 | private byte[] distance; |
| 13 | private java.util.Timer updater; |
| 14 | |
| 15 | private final int LIDAR_ADDR = 0x62; |
| 16 | private final int LIDAR_CONFIG_REGISTER = 0x00; |
| 17 | private final int LIDAR_DISTANCE_REGISTER = 0x8f; |
| 18 | |
| 19 | public Lidar(Port port) { |
| 20 | i2c = new I2C(port, LIDAR_ADDR); |
| 21 | |
| 22 | distance = new byte[2]; |
| 23 | |
| 24 | updater = new java.util.Timer(); |
| 25 | } |
| 26 | |
| 27 | // Distance in cm |
| 28 | public int getDistance() { |
| 29 | return (int) Integer.toUnsignedLong(distance[0] << 8) |
| 30 | + Byte.toUnsignedInt(distance[1]); |
| 31 | } |
| 32 | |
| 33 | @Override |
| 34 | public double pidGet() { |
| 35 | return getDistance(); |
| 36 | } |
| 37 | |
| 38 | // Start 10Hz polling |
| 39 | public void start() { |
| 40 | updater.scheduleAtFixedRate(new LIDARUpdater(), 0, 100); |
| 41 | } |
| 42 | |
| 43 | // Start polling for period in milliseconds |
| 44 | public void start(int period) { |
| 45 | updater.scheduleAtFixedRate(new LIDARUpdater(), 0, period); |
| 46 | } |
| 47 | |
| 48 | public void stop() { |
| 49 | updater.cancel(); |
| 50 | updater = new java.util.Timer(); |
| 51 | } |
| 52 | |
| 53 | // Update distance variable |
| 54 | public void update() { |
| 55 | i2c.write(LIDAR_CONFIG_REGISTER, 0x04); // Initiate measurement |
| 56 | Timer.delay(0.04); // Delay for measurement to be taken |
| 57 | i2c.read(LIDAR_DISTANCE_REGISTER, 2, distance); // Read in measurement |
| 58 | Timer.delay(0.005); // Delay to prevent over polling |
| 59 | } |
| 60 | |
| 61 | // Timer task to keep distance updated |
| 62 | private class LIDARUpdater extends TimerTask { |
| 63 | @Override |
| 64 | public void run() { |
| 65 | while (true) { |
| 66 | update(); |
| 67 | try { |
| 68 | Thread.sleep(10); |
| 69 | } catch (InterruptedException e) { |
| 70 | e.printStackTrace(); |
| 71 | } |
| 72 | } |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | @Override |
| 77 | public void setPIDSourceType(PIDSourceType pidSource) { |
| 78 | // TODO Auto-generated method stub |
| 79 | |
| 80 | } |
| 81 | |
| 82 | @Override |
| 83 | public PIDSourceType getPIDSourceType() { |
| 84 | // TODO Auto-generated method stub |
| 85 | return null; |
| 86 | } |
| 87 | } |