The previous Herbert robotic life-forms all had a single logic circuit and while some made use of different components, the results were the same from a logic point of view. If the robot has enough power then do something. Not a very exciting logic circuit, but something necessary for all life, even artificial life. We can continue to use this simple logic design in one form or another, even with very advanced life-forms. Slightly modified it can become: If you are hungry then eat. For now we will leave it as is and continue by adding more logic circuitry to the robots.
The simplest logic circuits available are the same as the logic operators taught in any introductory computer class: NOT, AND, OR & XOR. These logic chips can be made to suit the purposes of the next stage in robotic life-form evolution, but would require a lot of additional support circuitry. Lacking space on the demo platform, we will instead opt for an integrated circuit that can accomplish our next task: which direction is the better power source?
To answer this question Herbert 1701 Species D will make use of a comparator chip. In simplest terms, a comparator takes two inputs and determines whether one input is higher than the other. Generally the inputs are voltage levels that are being compared. The comparison between the two voltages usually produces one of two outputs, either a ground level or an open circuit.