Polycopters

Background reading

• http://vicacopter.com/vika1.php (via http://hackaday.com/2011/01/17/tri-rotor-helicopter-with-full-autopilot/)
• http://aeroquad.com

Hardware choices

CPU

• Android phone - free GPS/gyro/cam/Wifi, but long boot time - even with a separate watchdog, crashed phone = crashed copter. Still need to break out an interface to motor control board.
• Arduino 2009 / UNO - nice hardware as has A+D I/O built in + neat shields for motor control. GPS/gyro/cam/control method will still need to be worked out. Memory space too limited for full autonomy?
• Arduino Mega - as above, more expensive but more memory, enough for full auto?

Altitude sensor

• Barometer - least sensitive, probably best for high-flying vehicles. Needs to be kept away from the wash from the propellers.
• Ultrasound sonar - very sensitive for low-level flight, but tops out at a few metres.