Re: AW: Re: AW: Re: [ Paparazzi-devel] Prob =?ISO-8859-1?Q?lem using USB joystic?= k+telemetry link as R C replacement

[martin]

Hi,

the joystick stuff was a test to see if it is possible to use telemetry
for RC. We did some flights and it worked fine. You have to set some
variables so that the autopilot does not override, look in the joystick
block of flight_plans/finowfurt.xml. Still there might be some problem
with pitch angle...don't remember. It was only a "minimal invasive"
change in the code.

I think we should have the option for RC through telemetry. On
Spitzbergen we had severe problems with interference in the 35MHz band
from various scientific experiments, a high voltage power supply, a GSM
direct radio link and air traffic beacons that were running there. We
had not expected that in the wilderness...  The "old" PPM code should
not be removed completely though.

Recently we did some tests (in_progress/rctx) that showed that is
possible to do RC telemetry even for manual (joystick.c was auto1 only).
There seem to be several people working on this, there might be an
option to use 2.4GHz (fasst, spektrum, ..) receivers directly.

The first thing would be to connect a Twog with an XBee to the PPM
output of a standard RC transmitter and have this as the main control
(using rctx). It should be possible to add some buttons/LEDs and to
control multiple aircrafts (one by one) through this one RC transmitter.
Send RC data from the laptop (generated by a joystick) is the next
option. We should discuss a safe extension of the fbw/ap mechanics for
another RC signal source.

Martin

Am 23.05.2009 um  Uhr haben Sie geschrieben:
> Hi Gautier,
>
> thanks for your help! Today I managed to get the right messages sent
to the
> aircraft, now roll/pitch/throttle can be
> controlled by the joystick. :-)
>
> Now the servos seem as they cannot decide which specifications to
follow, the
> one from the autopilot and attitude
> control or that from the USB joystick: they jump around. E.g. even if
I give
> full throttle, the motor controller seems
> to toggle between full and no throttle.
>
> If I move the joystick, any value != 0 should override the autopilots
steering
> commands in order to have control
> over the airplane even if does weard things.
> I did a quick view of
http://paparazzi.enac.fr/wiki/Theory_of_Operation but I
> need to understand how the values for
> roll/pitch and throttle are calculated. Exists an overview how the
values are
> handed over  from main_ap.c, nav.c and
> fw_h_ctl.c? Think I will print out these files and take them to bed
with me for
> reading this night. :-)
>
> Best, Rainer
>
> ----Urspr
>