Re: [Paparazzi-devel] IMU, jeti and SD logger

[Martin Mueller]

Hi Cedric,

> I am still thinking about my idea of having a minimalistic UAV with
> just the jeti telemetry and the jetibox as a ground station and use
> an onboard data logger.
> In short I will have only a double line lcd and 4 push buttons on
> the transmitter while flying, but I will be able to replay the
> flight after landing.

as you say, there seem to be people e.g. over at Mikrokopter that use
Jeti and the Graupner HOTT system to display airborne data. The big
backdraw is that they there is no data uplink (e.g. for setting
waypoints).

Had started to implement a Paparazzi telemetry display with a Turnigy
T9X for the exact same purpose. It also would allow to send RC
signals as well as Paparazzi telemetry (e.g. move waypoint) through
the XBee link. It never left the demonstrator state - should publish
that.

> My idea is to make a fork from the logger code that one can find
> in the paparazzi project 

The Data_Logger contains FAT code that is not easy to incorporate into
the Paparazzi architecture as it just waits if the SD card delays
(which can be several 100ms).

> Another question : how does the real GCS get the flightplan ? 
> during compilation or does the plane (or the server only) send it
> to the GCS ?

The flight plan is given to the 'gcs' by the 'server' based on the
aircraft ID and checked with the MD5. The onboard software only has
the compiled flight plan, but no xml. There were some plans to do
that but it never happened. One step towards that is that the flight
plan is stored using the MD5 sum and the Data_Logger decoder uses
that MD5 hash to decode the data on the SD card rather then using the
aircraft ID. So you can decode SD content for older flights.

Martin