[Paparazzi-devel] confused between telemetry and datalink

[Zouhair Mahboubi]

Small question:
How is dl_parse_message supposed to differentiate between messages 
received from the ground station as part of the datalink (uplink) and 
those that maybe received from other airborne ACs (telemetry)

It seems like the messages.xml uses the same message ID for messages in 
both telemetry and datalink. (per example GPS and PING have the same id)
For the life of me I can't see how the autopilot code differentiates 
between the two since as long as  DOWNLINK defined, the dl_parse_msg is 
called if a valid message is received.

The reason of the confusion is that I am trying to parse a telemetry 
message sent by one AC on the other. I've managed to do this by defining 
some custom message in both telemetry and datalink, but when I tried 
with the GPS message it complained about Exception: Failure "Wrong 
alignment of field 'utm_east' in message 'GPS". (I changed the message 
ID to avoid collision , but that wasn't it) It seems to want a certain 
alignment for the fields, but I can't move the fields around because the 
GCS expects the GPS message to be in that order...

Any hints?

Happy holidays,
Zouhair