There are several miscellaneous smaller, yet key electrical components that were included in the game.

A 10K potentiometer with a user-friendly knob controls overall game difficulty. An C32 Analog to Digital port was connected to the wiper of the potentiometer, and the varying voltage levels were converted to a number that could be used as a PWM (Pulse Width Modulation) duty cycle to set the speed of the targets' left and right motion, as well as an indication to set other difficulty settings like cool-down time of the laser guns.

Circuit schematic of difficulty sensor

For our game mode sensor, a ON-ON toggle switch was used with one ON wired to 5V and the other to 0V. A C32 port was configured to be an input, and reads high or low depending on the orientation of the switch.

Circuit schematic of game mode switch

The coin sensor circuit is shown below. Resistor values were calculated from the datasheet of the opto-interrupter (which is a combination of an IR-emitting diode and a phototransistor). Since the opto-interrupter signal is above the lowest voltage needed to be recognized as a high signal, no signal conditioning was needed.

Circuit schematic of coin sensor