Wiring or Arduino UAV controler PCB based on inertial sensors, please suggestions!!!

Hi to all,

I can see you community are thinking in arduino for UAV controllers, i am designing some uav boards for a complex universitary project but development is too slow and i am thinking to build a wiring or arduino based PCB with all hardware integrated in a small board to start playing.

The board will have:
- ATmega128 (under wiring)
- inertial sensors for 6DOF (without any vertical board!!!)
- Absolute pressure (altitude)
- Diferential pressure (pitot-tube)
- Xbee Pro (100mw)
- optional 2 axis compass (HM55B)
- 8 x servo output
- 1 x GPS (uart) input for a external any nmea gps
- 1 x PPM input (4 servo input)
- battery voltage and probably 2 extra analog input.
- size - probably no more than 40 x 65 mm

I can study any suggestion, but it have to be esential.

IMU - this small board have a interesting conbination of inertial sensor to complete 6DOF in order to avoid vertical boards:

Acelerometer (X,Y,Z) - MMA7260Q (analog output) or LIS3LV02DQ (SPI output)
Gyros (X,Y) - IDG-300 (3 gyros in the same chip analog output)
Gyro (Z) - MLX90609 (analog and SPI output)

It is really compact solution,

in my other project i am acquiring analog sensors thought 16 bit ADC but in this project i would like to use AVR analog inputs.

i attach some PCB and schematic progress (very preview), please any suggestion will be welcomed.

Questions,

- I am using a 4017 CMOS to decode PPM signal from microcontroller and in this way only use a PWM output for all servos, it could be dificult to implement in wiring or arduino, is it? Wiring seems to have 8 PWM outputs, it could be better to remove 4017 and connect servos directly to AVR???

- Accelerometers conected by analog (MMA7260Q) or SPI (LIS3LV02DQ)?

I think it could be good design for non software-experts-uav-hobbyist like me, complete solution and all very very easy.
jlcortex