Player Circuit Schematics
E128 Pinout
We used a Freescale Adapt9S12-E128 Microcontroller mounted on an SPDL protection board to serve as the core brain of our PLAYER. The main reasoning behind this choice was that we wanted easy implementation of multiple PWM channels for our prop motors and servos, and we wanted to be able to use the 218 Events and Services Framework to more easily implement all the complex game logic while not worrying about limited program memory space.
LiFKIM PIC
Per project requirements, we included a PIC16F690 microcontroller programmed entirely in assembly language to communicate with the LiFKIM module. This PIC took instructions over SPI from the main E128 brain and shuttled them over SCI to the LiFKIM board. Responses from the LiFKIM were then relayed back by this PIC to the E128. This micro had no other purpose than serving as a middleman for these communications.
Propellers/Servos
We used 4 simple motors in total (besides the lift fan) on our hovercraft. Two DC motors were attached to propellers and pushed us forward while allowing us to steer with differential PWM control. And we used 2 servos to control our kicking and energy level display mechanisms.
Player Power Board
We decided to use 4 batteries to power our various hovercraft subsystems at varying voltage levels. 7.2V from one NiCd battery was supplied directly to our DC motors for propulsion and steering. Another 14.4V from two NiCd batteries was directed to the Lift Fan Kontroller and Impact Monitor (LiFKIM), which powered the blower fan used for hovering. Lastly, another 7.2V was driven off a NiCd battery to power the E128 microcontroller, and that same line was tapped with an LDO 5V regulator to supply voltage for the rest of our circuitry, including LED lights and servos. We decided to split up 4 batteries into these 3 distinct channels in order to maximize hovercraft operation time. The 2 DC prop motors drew about 6 amps on their own, and the lift blower fan required another 3 amps. Our 1800mAh NiCd batteries honestly weren't the ideal solution for long run-time, but they definitely were the cheapest available option. Had we decided to spend more money on batteries, we could have went with 3000+ mAh NiMh packs and possibly only used 2 in total on the PLAYER.
Team Color Switch
We also needed to include a way to tell our hovercraft which team to play for (Red or Green). For this we used a simple toggle switch that was normally pulled down low for the Green side.