Help with Programming a trigger!

Technical Java
1

Hi I’m a programmer on team 5464 and we need to know how to program a motor to a trigger on a joystick. We are fairly new to Java, so you may need to explain the steps. We do not know where to begin. We have a code to move a robot.

Thank you for your time

2

Have you looked at any instructions or sample-code. One good place to start is within File --> New --> Other… --> Example Java Projects -->CommandBased Robot --> GearsBot.

3

Are you using iterative robot or command based?

4

I think it is command based in Eclipse. I could be wrong.

5

Be aware that “trigger” may not always be a trigger in code. On a regular joystick you are probably going to use something like the following with shooter being some sort of motor controller such as CANTalon shooter = new CANTalon(10);

    if(stick.getTrigger()) {
          shooter.set(1.0);     // turn it on when pressed
    } else {                     
          shooter.set(0.0);   // turn it off when released
    }

We would have this inside the while loop of the operatorControl function (SampleRobot based project) but that will presumably vary with types of robot projects.

!!!However, if you are using something like a Playstation type controller (such as Logitech F310 with switch on back in X position), the two triggers may actually show as a pair of axis (each with values on a 0-1.0 scale) instead of as a trigger. On ours the left trigger is axis 2 and the right is axis 3 but you can use the USB section of the driver station to determine yours. This then looks more like the following.

if(stick.getRawAxis(3) > .5) {    
    motor.set(1.0);
} else {
   motor.set(0.0);
}

You could also have variable power from 0 to 1 if you just did

   motor.set(stick.getRawAxis(3));

It should be 0 when not pressed and range up to 1.0 when fully pressed.

6