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