[adciv]

It needs to be plugged into the Rleay section. Lets go from there. By plugging it into the DIO, you're setting it to reverse, as the reverse pin in the Spike is getting the 5V from the DIO. Lets try setting it to reverse in code while it's on the relay panel.

    public void operatorControl() {
        chassis.setSafetyEnabled(true);
        while (isOperatorControl() && isEnabled()) {
            double speed = mainStick.getY();
            double rot = -mainStick.getX();
            chassis.arcadeDrive (speed, rot);

            // Solenoid
                spike.set(Relay.Value.kReverse);
        }
    }