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
General parts supplier: Mouser.com