Simple Auto

Autonomous OpMode

Now that the kitbot can move in teleop mode, it is time to make it move during the autonomous mode. The autonomous mode is typically the first 15 seconds of the match but the exact length may vary from year to year. An effective auto can be a very valuable addition to a robot for a variety of reasons. Point values are typically increased during auto and sometimes ranking points associated with completing tasks during auto. Additionally both game pieces and your robot are in a known position allowing for consistent points. You also need to coordinate your autonomous routine with your alliance partners so it is important to have multiple routines and the ability to adjust them.

An autonomous routine is simply an OpMode that gets run during the autonomous portion of the match. When writing an OpMode that will be run during the autonomous mode, there is an @Autonomous annotation that is added above the class definition. This annotation tells the driverstation to place the OpMode under the autonomous selector. This OpMode will use a Timer to base its behavior off of the time elapsed from the beginning of the autonomous period. Time-based autos trade off simplicity for reliability, since slight variations in starting configuration could cause your robot to take more or less time to perform different actions

The code for the auto will be added to the MyAuto.java file inside the opmode folder. The goal of the auto is to drive forward at half speed for four seconds then stop. The Timer class has the hasElapsed(double seconds) function which returns true if the specified amount of time has passed. This function can be periodically checked as the condition to an if statement to stop the robot after four seconds

CTRE

/*
 * This method runs periodically, using the same period as the Robot instance.
 *
 * Additional periodic methods may be configured with addPeriodic(),
 * which can have periods that differ from the main Robot instance.
 */
@Override
public void periodic() {
  if (autoTimer.hasElapsed(4.0)) { // Drive for 4 seconds after the start of auto
    robot.drivetrain.arcadeDrive(0.0, 0.0); // Stop the drivetrain after 4 seconds

REV

/*
 * This method runs periodically, using the same period as the Robot instance.
 *
 * Additional periodic methods may be configured with addPeriodic(),
 * which can have periods that differ from the main Robot instance.
 */
@Override
public void periodic() {
  if (autoTimer.hasElapsed(4)) { // Drive for 4 seconds after the start of auto
    robot.drivetrain.arcadeDrive(0.0, 0.0); // Stop the robot after 4 seconds

If hasElapsed(4) instead returns false, then less than four seconds must have elapsed so the drivetrain should be told to drive forward at half speed.

CTRE

  } else {
    robot.drivetrain.arcadeDrive(0.5, 0.0); // Drive forward at half speed with no rotation
  }
}

REV

  } else {
    robot.drivetrain.arcadeDrive(0.5, 0.0); // Drive forward at half speed with no rotation
  }
}

Running Your Auto

To test the auto routine, start the simulation, and connect Advantage Scope. Then, select autonomous mode and MyAuto OpMode in the Sim GUI. Now when the robot is enabled the auto should run.

Practice

Try adding on to this auto yourself. For example, the robot could drive forward at half speed for four seconds, turn counter clockwise for two seconds, then drive forward at full speed for three seconds. You could also try creating additional autonomous OpModes so you can select between the different autos you have created.