Photos and circuit diagrams made in Fritzing are shown below. The circuit layouts are meant to minimize the number of digital pins used and to maximize the number of sensors and actuators used. The pin numbers referenced in the diagrams correspond to the numbers of the digital pins on the Arduino board. Every digital I/O pin on the Arduino Uno R3 board was used with the exception of pins 0 and 1. Pins 0 and 1 serve as serial communication pins, and they were left unused so as to not interfere with serial communications during operation. In order to further expand the capabilities of this robot with more digital devices, the Arduino’s analog pins would have to be used as general I/O pins. Alternatively, less useful devices (e.g. indicator LEDs) could be removed to free additional digital pins.