Introduction to Motors

Overview

Motors drive your robot's movement. In FRC, you will primarily use motor controllers from CTRE (Talon FX) and REV (SPARK MAX). This lesson covers creating and controlling these motors in Robot.java.

Objectives

You will learn to:

Create motor instances in code.
Control motor speed and direction.
Stop motors safely.
Work with CTRE and REV hardware.

Robot.java Lifecycle

robotInit(): Runs once at startup. Create your motors here.
teleopPeriodic(): Runs repeatedly during driver control. Update motor outputs here.

CTRE: Talon FX

The Talon FX is a high-performance motor controller with a built-in encoder. It requires the CTRE Phoenix 6 library.

Talon FX Example

package frc.robot;

import edu.wpi.first.wpilibj.TimedRobot;
import com.ctre.phoenix6.hardware.TalonFX;
import com.ctre.phoenix6.controls.DutyCycleOut;

public class Robot extends TimedRobot {
    // Create motor instance with CAN ID 1
    private TalonFX m_motor = new TalonFX(1);
    // Create control request for duty cycle output
    private DutyCycleOut m_output = new DutyCycleOut(0);
    
    @Override
    public void teleopPeriodic() {
        // Set motor to 50% speed forward (range: -1.0 to 1.0)
        m_motor.setControl(m_output.withOutput(0.5));
    }
}

REV: SPARK MAX

The SPARK MAX supports both brushless (NEO) and brushed motors. It requires the REVLib library.

SPARK MAX Example

package frc.robot;

import edu.wpi.first.wpilibj.TimedRobot;
import com.revrobotics.spark.SparkMax;
import com.revrobotics.spark.SparkLowLevel.MotorType;

public class Robot extends TimedRobot {
    // Create motor instance: CAN ID 1, Brushless motor type
    private SparkMax m_motor = new SparkMax(1, MotorType.kBrushless);
    
    @Override
    public void teleopPeriodic() {
        // Set motor to 50% speed forward (range: -1.0 to 1.0)
        m_motor.set(0.5);
    }
}

Control Basics

Speed: Values range from -1.0 (full reverse) to 1.0 (full forward). 0.0 stops the motor.
Multiple Motors: Create separate instances for each motor (e.g., left and right drive motors).

Multiple Motors

Controlling two motors:

package frc.robot;

import edu.wpi.first.wpilibj.TimedRobot;
import com.ctre.phoenix6.hardware.TalonFX;
import com.ctre.phoenix6.controls.DutyCycleOut;

public class Robot extends TimedRobot {
    // Create left and right motors with different CAN IDs
    private TalonFX m_left = new TalonFX(1);
    private TalonFX m_right = new TalonFX(2);
    private DutyCycleOut m_output = new DutyCycleOut(0);
    
    @Override
    public void teleopPeriodic() {
        // Set both motors to 50% speed
        m_left.setControl(m_output.withOutput(0.5));
        m_right.setControl(m_output.withOutput(0.5));
    }
}

Key Points

Remember:

Create motors as private fields.
Use unique CAN IDs.
Talon FX uses setControl.
SPARK MAX uses set.
Range is -1.0 to 1.0.

Resources

Controllers & Inputs CTRE Setup REV Setup

Open full interactive app