Hi, Not sure where to go with this one so in the hope Tridge might be willing to take a look, here goes:
I am working on the Mavlink->frsky telemetry project trying to get it fully functional with Plane (this is an old project, using a teensy Arduino board to convert mavlink messages into simulated FrSky Smartport sensors and these sensors’ data displayed in lua screen on the Taranis radio), and this works perfectly on Arducopter 3.3 and 3.4dev, but I have issues with barometric Altitude values returned when running this with Plane 3.5.3 (and 3.5.2). This is done when the arduino code calls the relevant function in the gsc_mavlink library:
`ap_bar_altitude = mavlink_msg_vfr_hud_get_alt(&msg) * 100;`
(this is line 468 in mavlink.ino for info) - the intention is to set ap_bar_altitude to the cm altitude (hence the *100) but the value returned by this call does not seem to represent barometric Altitude at all. the value returned (by mavlink_msg_vfr_hud_get_alt(&msg) before it is multiplied by 100) is a number in the 100’s and this keeps incrementing over time, even when the plane is stationary. Its as if the wrong value is being returned by the library call - this is supposed to represent Id 8 in Mavlink Msg #74. Sorry I’m new to all this so hoping what I have written makes sense to someone! I have reformatted the info here to hopefully make it more understandable.
The project is using the Mavlink v1.0 c++ common libraries included within the Teensy code project. Some project details:
Project link: https://github.com/Clooney82/MavLink_FrSkySPort
GCS_Mavlink libraries used by this project: https://github.com/Clooney82/MavLink_FrSkySPort/blob/s-c-l-v-rc-opentx2.1/libraries/GCS_MAVLink.zip
Just to reiterate - my query here is specific to Ardupilot Plane running on Pixhawk (its a Pixhawk Lite in my case), as the Altitude telemetry is read perfectly by the same Arduino code from a pixhawk running Copter 3.3.
Any help would be really appreciated. Cheers, Paul