UPDATE: The project is complete have a look at everything here. Nerf Gun Hack part 1, part 2, part 3
This is part 2 of the Nerf Gun hack, you can see part 1 of the project here. Last time some wiring was done to allow us to remotely control the three internal motors. This time the control wires are connected to a simple circuit that uses two darlington transistors to spin up and fire the gun. A 16f88 PIC microcontroller is being used to monitor an IR beam and fire the unit when the beam has been broken. The IR beam consists of an Infrared LED and an Infrared Transistor. To determine when the beam is broken an analog reading is taken by the PIC when the IR LED is off and again when the IR LED is turned on. The difference is used to determine the state of the beam, if the difference is small the beam is not broken and if the value is large we know something is blocking the beam. When the beam is broken the controller turns on the first darlington transistor to spin up the rotating motors, then a short time later the second darlington is activated which fires the dart into the spinning wheels.
