**2.1 Control paradigm**

In manual operation, the RCX delivers a constant 9V to each of its power outputs, and the remote operated vehicle (ROV)'s motors are controlled by switching the current flow with Double Pole Double Throw (DPDT) rockers switches. When the rocker switch is in the neutral position, no current flows. When it is switched forward, the current flows and the motor turns forward. When the DPDT is switched backward, the poles are reversed, resulting in the current flowing backwards, making the motor to turn backwards. Additionally, in each motor's control circuit is a manual override Double Poles single Throw (DPST) switch to give RCX direct control of the motor. With this switch, autonomous control can be turned on and off for motor individually, so the operator has the option of the RCX is controlling one function while another function controlled manually. One application of this ability would be the (ROV) hovering. The RCX would monitor the pressure and adjust the vertical thrusters while the operator could still manually drive in the horizontal plane.

The general control box design is a container for the RCX that is held with two hands on either side. The top has two horizontal motor control switch sets in reach of the thumbs in addition to the three switches. Each subroutine switch hooks directly into one of the sensor inputs and so when it is tripped it shorts out that input. In the ROBOLAB program a shorted input will return the maximum value of the sensor programmed to be hooked up to that input. When the maximum value is reached, the program can be triggered to do the task. This makes it possible for a manual switch to run a subroutine. The front of the box has the connection to the tether as a well as the vertical motor control switch set which is in reach of the index fingers. Additionally, the box has an AC adaptor input on its left side.
