Servers by jDrones

An Open Source Frsky Telemetry Script for the Horus X10,X12 and Taranis X9D,X9E and QX7 radios


(Markus Greinwald) #256

Hi Alex,
Thank you very much for this great work.
Before I use the Flight Deck telemetry but only yours support the Horus X12S.
At current I run the script under TX2.2.x on a Taranis X9D+ and HorusX12S.
For the autopliot I use the Pixhawk series and the ArduPilot Plane software.

Now I have a question about the displayed speed.
I only get the value from the air speed sensor. According to your description it should be possible to display the grundspeed or the synthetic speed.
If I use a Pixhawk without air tube the displayed speed is allways zero. On the log files I could read the groundspeed from the GPS values.

Have You any idea in witch direction I could search?

Thanks and best regards,

(Alex Apostoli) #257

Hi Markus,
the frsky telemetry library on the pixhawk sends down the telemetry link only 1 speed value.
Where it picks that speed value depends on arduplane configuration.
There are 2 possible configurations:

  1. you have enabled an airspeed sensor in arduplane: ARSPD_TYPE > 0
    in this case the telemetry library will try to use airspeed even if the sensor is unhealthy, if it’s unhealty (no tube) the speed will be 0, with the tube present you will get airspeed.

  2. you have not defined an airspeed sensor:ARSPD_TYPE = 0
    in this case the telemetry library will always send groundspeed (gps) even if physically the tube is present.

As you can see the script has no control on what gets sent by the library.

The only way I can think of to have both airspeed and groundspeed is to let the user enable such feature in the script config menu, for only the pilot knows if he/she has an airspeed sensor enabled on arduplane.
I do not fly planes so I’m asking you: would it be of any help to have an estimated synthetic “groundspeed” updated at 1Hz based on GPS coords?

If so I could:

  1. create a menu option to let the user enable “synthetic groundspeed”
  2. calculate “synthetic groundspeed” based on GPS coords updated at around 1Hz
  3. display both airspeed and “synthetic groundspeed”

what do you think?


(Markus Greinwald) #258

Hi Alex,

I fly planes and copters. Even I try to build a Quadplane.
But I have had to learn that the weight witch is maybe ok for a copter could be a no go for a plane.
Leason learnd - next time (in the winter) I will take more care about the weight.:grinning:

At the moment I fly planes and I like the virtual cockpit very much.

Yep the problem was the ARSPD_TYPE. I should erase the Pixhawk completly before place in a other plane.:thinking:
Before it was in the damaged Quadplane and there was a airspeed sensor inside.

I would prefere only one value at the screen. Airspeed or groundspeed. Ohterwise maybe to much information.

At the moment your display on the Horus is very well balanced.

Personaly I like the groundspeed because less problem with the calibration an the ugly tube.
Of course the indecated airspeed would be the best if the wind is stronger. But mostly my landing speed is to much and I need the full runway.

In a older article from 2010 I read about wind estimation without an airspeed sensor.
They use the GPS, accelerometers and extended Kalman filtering.
I think its already integrated in the actual ArduPlane V3.8.5 but I didn’t found some information about it.

On the mission planner I see too values.
Airspeed and groundspeed - even the airspeed sensor is type 0.
The values are different, so I think the airspeed value is the “calculated airspeed”.
In this case it would be very nice to select airspeed or groundspeed on the telemetry menue.


(Roman) #259


The airspeed is very important for a manual landing.

At an airplane, the ground speed may be negative if the wind speed is higher than the speed of flight

it is good to have both values

How can I get the airspeed to get an audio alert?

(Alex Apostoli) #260

Hi Roman, could you please explain better what you would like to achieve?

(Roman) #261

for manual landing the aircraft, use the switch SD:
special functions menu
Switch: SD ↑; Action: Play Value; Parameter: ASPD; repeat 1 sec

I need to have an available ASPD parameter, how this can be implemented?

(Alex Apostoli) #262

as I explained a couple posts back, there is just one speed sent from arduplane and I expose to OpenTX that speed with the GSPD sensor variable.
If you have an airspeed sensor fitted GSPD will hold the airspeed otherwise will hold groundspeed.
So just do the same with the GSPD variable, it should work!

hope I understood your need


(Roman) #263

Thank Alex
this will help me

about the speed I read in the source code for the githab:

// horizontal velocity in dm / s (use airspeed if available and enabled - even if not used - otherwise use groundspeed)
const AP_Airspeed * aspeed = _ahrs.get_airspeed ();
if (aspeed && aspeed-> enabled ()) {
velandyaw | = prep_number (roundf (aspeed-> get_airspeed () * 10), 2, 1) << VELANDYAW_XYVEL_OFFSET;
} else {// otherwise send sentpeed estimate from ahrs
velandyaw | = prep_number (roundf (_ahrs.groundspeed () * 10), 2, 1) << VELANDYAW_XYVEL_OFFSET;

(Alex Apostoli) #264

about the speed I read in the source code

yes, that’s the relevant code, as you can see either airspeed or groundspeed, never both!

(Markus Greinwald) #265

Hi Alex,
I have done a translation for the sound files in german language.
Maybe you like to add it to your script.
So far I didn’t have a cloud for upload.
Could you give me some adress for upload?


(Alex Apostoli) #266

Thanks Markus,
next release will also have german as language option!


(Markus Greinwald) #267

Hi Alex,

Is it possible to add values from the FrSky Telemetrie to your script?
I am particularly interested in the values of the rpm and temperature sensor.
The adresses could be fix and have to be adjusted on the sensors or they are adjustable on the menu of the telemetrie script.


(Alex Apostoli) #268

Hi Markus,
could you please explain in detail what you would like to achieve?

(Markus Greinwald) #269

Hi Alex,
I would try to be a little bit more accurate :grinning:
At the OpenTX I have two group of sensors.
Group one are the sensors direct connected to the X8R receiver over the Smart Port.
Group two are the sensor values send over the FrSky passtrough protokol also conneted to the Smart Port.

I have a RPM and temperatur sensor direct connecetd to the X8R reciver over the FrSky Smart Port
This values I like to display inside your script.
So maybe between “AltAsl” and “Spd” could be room for “RPM” and “TMP”.

Hope this explanation make it a litte bit more clear.


(Alex Apostoli) #270

Hi Markus,
now I understand what you would like.

  • first problem is that I already expose Fuel, Tmp1 and Tmp2 to OpenTX, it’s easy to comment them out of the code
  • then I would have to get real frsky sensor values and show them on screen, I can sure find a good place

I can probably make a custom version for you and give you the sources but after that you’ll have to mantain it, it means that when I release a new version you’ll have to inject the changes by yourself (best solution is to fork my github repo and keep your customized version there), this because you’re request is very specific even though I recognize that by running full screen in one time mode the script prevents users from defining custom telemetry pages

(Markus Greinwald) #271

Hi Alex,

I have taken a deep look on your code.
So I decide to ask you about the possibilitys :grinning:

I think I would be able to build a compiled script (first time I ever did that) and fork your github repo.
So if there would be an update I could inject the changes.
So far the plan :roll_eyes:

I like to replace the “AltAsl” for the “RPM” and the “Power” for the “Temperature”.
If You show me the code lines and what I have to change I will try to customice my script.
A example would be very helpful.


(Alex Apostoli) #272

Markus how about having your sensors on a different page of the script accessible with the page up/down button? Something similar to the message history

(Alex Apostoli) #273

Markus what are the sensor names you would like to display, I need a screenshot from OpenTX with the exact values for name, id, instance, precision, I think I found an elegant way to do what you ask that can be incorporated into the script :slight_smile:

(Luís Vale Gonçalves) #274


Why not use these:

won’t miss any from the standard OpenTx/FrSky telemetry Sport ?

and if detected create additional pages ?

(Alex Apostoli) #275

Hi Luis,
I don’t have access to sensors by ID but only by name, but my idea was close to yours, I thought about having the user declare them in a config file for an extra senosr panel in the left side that will be activated by a short press of [PAGE UP/DOWN] only on the horus though

This config would be read only at startup and therefore consume very little resources

P.S. welcome back :slight_smile: