Taranis Inputs/Mixer and Mission Planner settings [Solved]

[UAVSkies (Asim)]

@smartdave @dkemxr @Marc_Dornan

I am sort of new to Open Tx and Taranis and trying to get a better understanding on few things how they work together.

The above diagram and setup works, however a number of things are very confusing.

1. Main-out Pin 1 has left servo connected to it.
2. Main-out Pin 2 has right servo connected to it.
3. Main-out Pin 4 has ESC for thrust motor.

No matter what you do, if I want Thrust motor to be connected to main Out -3, FC will not allow you to do that. Is it hard coded in the Plane firmware that one must use main Out 4?

What also confuses me is the servo output section inside mission planner.

How it correlates to what you set inside Taranis radio inputs and Mixer? “Or” the servo out section in MP is actually a mixer itself and you don’t need to do any mixing inside the Taranis radio?

if that is the case why in Ardupilot documentation is says, for wing plane you must use Pins 1,2, 4 and set;

SERVO1_FUNCTION = 77
SERVO2_FUNCTION = 78
SERVO3_FUNCTION =70

But the motor only works off Main out Pin 4, so then why the documentation is suggesting using SERVO3_FUNCTION for motor?

Very confusing. Does anyone update these documentation with easy to follow instructions…

[smartdave (Dave Glover)]

I have never done anything with the plane firmware, but it seems odd that servo4 would be hard coded for throttle, especially since inside MP it allows you to change it.

Let me read up on it a little

[UAVSkies (Asim)]

I am banging my head against the wall for the last 2 hours. I can get everything to work, expect I can not use CH3…

Ardupilot documentation is so dated. I think we all should take a break from developing new features and first clean up the whole library…

[smartdave (Dave Glover)]

Channel 3 on the radio or M3 output on the flight controller

[UAVSkies (Asim)]

FC main out 3…not radio. take a look at my diagram above., It shows how TX, and MP channel mapping is done.

[smartdave (Dave Glover)]

First you have this: Outputs are provided to activate servos, motors, relays, etc. to control the vehicle. Any autopilot output can be assigned the desired vehicle control output function via the SERVOx_FUNCTION parameters

[UAVSkies (Asim)]

Doesnt work that way in plane mode…

[Marc_Dornan]

Nothing is hard coded on either end!

You can assign any channel to throttle in Ardupilot (Mission Planner) or you do the same in OpenTX.

In general I prefer to leave the radio channel assignments alone and never use mixes in OpenTX. The FC does the mixing.

I can explain better later.

[UAVSkies (Asim)]

Hey Marc take a look at my diagram.

If I connect motor ESC to Main out 3, the throttle doesnt work.

Its all %^*# to me…confused

[Marc_Dornan]

I can help you later. You can assign physical servo3 to any function you like in MP.

[UAVSkies (Asim)]

Ok I will wait…i am lost…

[Marc_Dornan]

Once the penny drops it will be easy. Trust me.

[smartdave (Dave Glover)]

Do you have a copy of your parameters file?

Also as mentioned you don’t do any mixing in the radio as the FC takes care of all of that.

[UAVSkies (Asim)]

I am not doing any mixing buddy. take a look at the diagram above One to One relationship no mixing.

wing parameter file.param (18.1 KB)

Note: its a wing, so Aileron acts as both Aileron and elevator. which is also called Flaperon…

[dkemxr (Dave)]

@UAVSkies

At another documentation place it gives again different info

You are you looking at 2 different flight firnware stacks Asim. The "SYS_AUTOSTART is the giveaway. That’s a PX4 parameter. Sick with Ardupilot info.

[UAVSkies (Asim)]

I noticed that and removed that reference, but the CH3 can not be used for Motor ESC, problem still not solving.

[dkemxr (Dave)]

As Marc said any output can be used for the motor if it’s assigned as such (70). Does the throttle chan move in the Radio Calibration screen? Armed and Safety button pressed (parameter file shows it enabled) before attempting to run the motor?

Elevon. Flaperons serve a different function.

[UAVSkies (Asim)]

hmmm…now everything is working…what the hell :))

final setup and it works fine…very strange, not sure why it was failing throttle before on CH3

[dkemxr (Dave)]

Great! Changing servo parameters requires a restart of the FC perhaps that was it? Anyway, on your way. Are really using AP3.6 or did this just land in the wrong thread?

[Marc_Dornan]

Good job. Beat me to it. With these things you do have to walk away sometimes.

Ardupilot is a steeper learning curve but it is by far the most powerful open source autopilot.

I would spend a little time on OpenTx as well. That is extraordinarily powerful. Any input can be assigned to any output. In fact Yaapu (Alex) is pretty close to a LUA GCS on an OpenTx radio now that he has bi-directional telemetry from his LUA scripting working.