So the very first thing I did was add the software serial line. I used a library that can be found here:
http://arduiniana.org/
Next, we created an array in RAM for the WPs that we upload. We decided that writing to the EEPROM while flying might be a bad idea, so we have actually two sets of WPs, so we needed a flag to tell the AP where to read the WPs from.

The biggest challenge that I faced was simply creating a command buffer and filtering out bad data on the software serial line.

An alternative would be to use an Arduino Mega which has 3 dedicated serial lines, which means you could read off it much faster.

Good luck!

Hola Jesús!

Yo soy alumno de la ETSIA, también. Estoy muy interesado en estos temas y tengo algunos proyectos en marcha o en mente.
Si algún día te apetece hablar de estos temas, no dudes en ponerme un email y nos vemos por la escuela.

Un saludo!

I tested it but never flew it with the gamepad since I got my radio equipment to work.

The airborne code can be found on svn under the name of joystick.c and the GCS version for the joystick is somwhere on SVN too, IIRC.

Yep, it's only for the AUTO1 and AUTO2 modes but it could be altered quite easily to work in all modes.

It'd be quite possible to use the ppz completely without MANUAL-mode and with the gamepad/joystick only, I'd recon. The only thing that you'll have to take into consideration is that you have to have your PID gains tuned before you attempt to fly with only AUTO1 and 2. But I take it you have your Paparazzi tuned for your A/F already so that shouldn't be a problem? Another thing that I'd do if I were you would be to make use of all the joystick buttons and throttle so that you could have complete control over all the functions of the Paparazzi without having to use mouse or keyboard in between. I.e. you could use the joystick buttons to change the flying mode of the PPZ etc. It'll require some programming, I think, but shouldn't be too hard to accomplish.

-Sami