Basic Programming

General Programming stuff

By Jack, Ryan, and Ishan

• Link to WPILib docs
  • Link to how to install libraries on WPILib VS code
• Link to CTRE docs

Solenoids:

• Class: DoubleSolenoid
  • Import:
    • import edu.wpi.first.wpilibj.DoubleSolenoid;
  • Initialization:
    • DoubleSolenoid solenoid = new DoubleSolenoid(PneumaticsModuleType.CTREPCM, forwardChannel, reverseChannel);
  • Usage:
    • Extend:
      • solenoid.set(DoubleSolenoid.Value.kForward);
    • Retract:
      • solenoid.set(DoubleSolenoid.Value.kReverse);

Motors:

• Classes: TalonFX, WPI_TalonSRX
  • Mechanical-speak: Falcon/Falcon 500
  • Programming speak: TalonFX
  • Mechanical-speak: Any other CTRE motor type (it will be connected to a talon SRX controller)
  • Programming speak: WPI_TalonSRX
• Imports:
  • import com.ctre.phoenix6.hardware.TalonFX;
  • import com.ctre.phoenix.motorcontrol.can.WPI_TalonSRX;
• Initialization:
  • TalonFX motorFX = new TalonFX(motorPort);
  • WPI_TalonSRX motorSRX = new WPI_TalonSRX(motorPort);
• Usage (for both):
  • Speed:
    • motorFX.set(speed);
    • motorSRX.set(speed);
• Built-in PID:
  • Setup:
    • motorFX.config_kP(0, kP); //kP being the P value
    • motorSRX.config_kP(0, kP); //kP being the P value
    • // other PID values are config_kI, config_kD, and config_kF.
• Usage:
  • public void setDesiredMotorDegree(double degree) {
  • int motorPosFX = (int) ((2048 / 360) * degree);
  • motorFX.set(ControlMode.MotionMagic, motorPosFX);
  • int motorPosSRX = (int) ((2048 / 360) * degree);
  • motorSRX.set(ControlMode.MotionMagic, motorPosSRX);}
  • The TalonFX and TalonSRX motor encoders record data 2048 units per revolution. The function .getSelectedSensorPosition() will return the encoder’s position since it was last reset. The encoder is not constrained to 0-2048.
    • We don't need to think about this anymore, since with phoenix v6, CTRE units changed to pure rotations as opposed to the # of pulses per full revolution. This is true unless we use a motor controller that requires Phoenix v5 (i.e. a (WPI_)TalonSRX).

Limelight --Needs to be updated

• Uses LimelightHelpers:

  • To

• Imports:

  • import edu.wpi.first.networktables.NetworkTableEntry;
  • import edu.wpi.first.networktables.NetworkTableInstance;

• Initialization:

  • NetworkTableInstance limelight = NetworkTableInstance.getDefault().getTable("limelight").getInstance(); // gets the table with limelight values
  • NetworkTableEntry targetX = limelight.getEntry("tx"); // target x position, like a coordinate plane with (0, 0) at the center of the frame

• Usage:

  • public double getTargetX() {
  • return targetX.getDouble(0.0); // parameter is the value to be returned if there is no target
  • // tV can also be used to get if there are valid targets in the frame
  • }

  PID: more in-depth link