PNav Autopilot requirements: 

Primary Objective: To create a  Parallax Propeller Autopilot for a fixed wing R/C aircraft using GPS as the primary form of guidance anywhere on earth.

Secondary Objectives:

Realtime Heads Up Display technology for first person flight 

High Level Requirements:

• GPS Navigation. Routines to store and calculate navigation parameters throughout a flight.   Additional input are permissible (ie thermopile, pitot tube, barometric pressure, etc)  but system must stand on its own for navigation.
  
• Radio Control Inputs and Outputs for command and control of servos
  
• SD Card Access
• Waypoint storage
• Data Logging with integrated Google Earth compatibility
• Video Downlink from onboard camera
• On Screen Display / HUD with relevant flight information.

Project Components Definition:

• GPS - Input of standard NMEA strings is complete with Perry's GPS_IO  SPIN code. I am using a US Globalsat 408 Sirf III chip.
  

• SD Card access is standard with Tomas Rokicki's Fat16 code.

Hardware:

• Processor: Parallax Propeller 8 core multiprocessor prototype board $25.
  
• Memory - FAT 16 compatible SD cards $5
  
• US GlobalSat GPS SIRF-III receiver $60
• 6 channels of R/C input/ 6 channels servo output. $~150
  
• SD Card for dataloging and Google Earth integration $10
  
• 2 video camera inputs and a switching mechanism $~100
  
• On-Screen Display, Fully controlled by the main system
• Video transmitter connection and RCA test jacks$150
• USB programmer jack and flash memory $25
  
• 4 mounted LEDs with one external IR LED jack $1
  
• 2 momentary switches  $5
• Part links to come...

General parts supplier:    Mouser.com