Spectre
Power Board
TIVA
Balloon Monitor
We used a PIC16F690 and a 20 Mhz resonator to read data from the balloon monitor, which told us if our balloon had been popped. The balloon monitor sent different packets of data depending on if the balloon was popped or not. This PIC queried the balloon monitor every few milliseconds and relayed the received data to the TIVA for processing.
Lift fan control
Circuit controlling the lift fan that filled the SPECTRE skirt with air to allow it to hover. The lift fan cannot run directly off the 14.4 V power supply, so two power diodes were placed in series to drop the voltage. A standard kickback diode is placed across the motor. A signal from the TIVA turned the power MOSFET (and lift fan) on and off.
Xbee
Propeller.
Servo and hot wire
We used servos to move the indicator flag (to let teams know if our SPECTRE was currently under control of an MI6) as well as the balloon popping mechanism. These servos only required a PWM input to move to certain angles.
The hot wire circuit used its own battery due to heavy power consumption when in use. The TIVA could turn the power MOSFET on and off to activate and deactivate the hot wire. An LED indicator was placed in parallel with the hot wire for safety reasons.