This is the state diagram of our system, along with the state, input and output definitions. In order to simplify our project, we chose to use a Moore machine design. This means that the output is only dependent on the states, and not on the input. Thus, the output will have an opportunity to change only when the clock rising edge has occured.

In general, the state diagram shows how the system will react when different inputs (X1, X2, and X3) are given to the robot claw. The state definitions describe what the robot is doing (or more simply, what the status of the robot claw is) when the robot claw is in a particular state. The input definitions describe what the binary code is for each particular type of input. The output definition is similar to the input definition, except that it associates a binary code to a particular type of output.

It was very important for our group to draw the correct state diagram. Because we are using VHDL, and VHDL is created using the state diagram, if we make a mistake with the state diagram, we will ultimately make a mistake in our VHDL document. Thus, when we try to use our VHDL document in the NOVA simulator, we will receive an incorrect simulation.

For an actual system, the inputs of the state system would come from sensors on the robot claw. The sensors would detect the presence of three different stimuli: whether an object is between the claws, whether an object is grasped by the claws or whether the claws are fully open.

For an actual system, the outputs of the state system connect to two transistors and four relays, that in turn would connect to the robot. The transistors and relays would allow more power to be delivered to the robot than what the digital circuit could supply by itself.