Published Frsky Mavlink Passthrough Protocol spreadsheet contains an error

ArduCopter Copter 3.5
1

Hi Guys

I thought you would want to know that the spreadsheet defining the Frsky Mavlink Passthrough Protocol linked on this page http://ardupilot.org/copter/docs/common-frsky-passthrough.html contains an error.

Data ID 5004 - HOME (2Hz)

The published order of the data elements from the LS bit side is:

Distance to home
Angle from front of vehicle
Altitude relative to home - offset 19 bits - WRONG

The actual order of the data elements from LS bit side is:
Distance to home
Altitude relative to home - offset 12 bits
Angle from front of vehicle

as per these define statements in the APMv3.5.3 Arducopter source

// for home position related data
#define HOME_ALT_OFFSET 12
#define HOME_BEARING_LIMIT 0x7F
#define HOME_BEARING_OFFSET 25

The spreadsheet should be correct don’t you think? It is currently the only definition of Mavlink Passthrough in the public domain as far as I know,
Regards
Eric

2

You could, if you are familiar with GithHub, submit a correction yourself. The wiki is maintained through this github repository. The XLSX file in question is ./images/FrSky_Passthrough_protocol.xlsx.

3

ok , I’ll do that as soon as I get the chance.

4

good catch. Will be updating the wiki page with the new spreadsheet shortly.