FrSky SxR Alternative Flight Mode Switching

Published by Mr. D on

FrSKY S6R Alternative Flight Mode Switching

Please note, this set up is based on the regular aircraft model in the S6R or S8R, not a flying wing or V-Tail. The channel positions are different for both types of model. Always test any stabilisation system to make sure that the control surfaces are working correctly before flying. I take no responsibility for any crashes.

I’ve set up a FrSKY S6R receiver for my EFlite Extra 260. I didn’t like the way the switches are setup, with switches being mapped directly to the output channels. To me it seemed all to easy to put it in a mode you didn’t want to (such as hover or knife edge when you want normal flight). Also if you want to go from stabilised flight to auto level, or vice versa, you have to go through unstabilised (normal) flight, which to me seems wrong.

Using the advanced features of the Taranis, I have come up with a solution where switch SB functions as  Auto-Level,  Stabilised, and  for normal, manual flight. Switch SC (optional) functions as  Knife Edge,  Off, and  Hover. I have also added a parameter which states SB must be in  (normal flight) for the Knife Edge or Hover modes to work. If you don’t want to use the Knife Edge or Hover features of the S6R

Step 1 – Mapping the switches

Our first step is to create Logical Switches to determine which flight mode we want to be in, based on the position of our SB & SC switches.

Logical Switches setup for S6R flight modes

L01 creates the condition for the Auto-Level flight mode. If SB reads less than 50 (Switch in the  position), switch L01 is active. I have put Auto-level in the up position because it’s easier to flick the switch up if you get in trouble than try to pull the switch down.

L02 creates the condition for the stabilised flight mode, SB-.

L04 creates the condition for the normal flight mode SB↓. This mode only goes active if SC- and L03 is active.

L05 creates the condition for the Hover flight mode. This mode only goes active if SC↓ and L03 is active.

L06 creates the condition for the Knife Edge flight mode. This mode only goes active if SC↑ and L03 is active.

Step 2 – Create the flight modes

For clarity in the Special Functions, I use the logical switches to activate flight modes. This shows the name of the flight mode on your Taranis’ display. It also enables you to make changes for each mode.

Flight Modes set up for the S6R

Give each Flight Mode a Name, which will be displayed on the screen of the Taranis when the mode is selected. For flight modes 1 to 4, set the Switch to the appropriate Logical Switch which is listed above. Flight Mode 0 (Normal) does not need to be assigned a logical switch.

Step 3 – Name the Outputs

This step is not essential, but it helps for clarity in the next step. Set the names of Outputs 9, 10, 11, & 12.

Outputs setup for S6R

Step 4 – Create the Special Functions

The last 3 steps have really been setting up for this. The Special Functions is where the magic happens and we output the correct values to the S6R based our selected flight mode. There are 2 parts to this, part A does all the work, and part B is optional audio confirmation of the modes changing.

A) Modifying the Channels

We need to create some channel override Special Functions and map them to our Flight Modes. These overrides create the correct output on channels 10 and 11 to activate the S6R’s flight modes.

Special Functions for S6R flight modes - channel output

If you run this through the simulator in OpenTX Companion, you will see the channel outputs changing with the switch movements and can compare them to the expected channel outputs in the S6R documentation. The S6R documentation and switches on the Taranis is a little confusing. When a switch is in the down position, it actually outputs 100 on the channel, not -100 as expected. So, switch up is -100, middle is 0, and switch down is 100.

B) Adding audible feedback

This is the last part, optional audio feedback when you change Flight Modes. I have created flight mode audio tracks and pre-installed them on my Taranis. There are plenty of tutorials on YouTube for creating audio tracks for the Taranis, so I won’t cover that here.

Special Functions for S6R flight modes - audio feedback

There you have it. This should get the S6R functionality working with, I feel, a better switch combination, a fail-safe on the Knife Edge and Hover modes, with visual and audible feedback.

It’s not working!

If you have this set up and the switches don’t work as expected. Enter the SxR setup LUA script and click on to page 2. If the option Quick Mode is enabled, disable it and the switches will all work.

Up to 11! Changing the gain

As one last note on the S6R, I have mapped my S2 dial to the deflection gain of the stabiliser. Go to the Mixes screen, double click on Channel 9 and use the following settings to use the full range of the S2 dial, rather than just middle to low or high. You could map this to either of the dials or triggers, however I found the dials more accurate than the triggers.

S6R gain dial mixer settings

Full OpenTX Code

Select the first Logical Switch and first Special Function positions available on your Model

Logical Switches

#FunctionV1V2AND SwitchDurationDelayDescription
L01a < xSB-33---------Auto-Level
L02a = xSB0---------Stablised
L03a > xSB33------------
L04a = xSC0L03------Normal/Manual
L05a > xSC33L03------Hover
L06a < xSC-33L03------Knife Edge

Special Functions

SF01FM4:Knife-edgeOverride CH10:Modes-100✔ ON
SF02FM4:Knife-edgeOverride CH11:Modes0✔ ON
SF03FM3:Auto HoverOverride CH10:Modes100✔ ON
SF04FM3:Auto HoverOverride CH11:Modes-100✔ ON
SF05FM2:Auto LevelOverride CH10:Modes100✔ ON
SF06FM2:Auto LevelOverride CH11:Modes100✔ ON
SF07FM1:StabilisedOverride CH10:Modes100✔ ON
SF08FM1:StabilisedOverride CH11:Modes0✔ ON
SF09FM0:NormalOverride CH10:Modes0✔ ON
SF10FM0:NormalOverride CH11:Modes0✔ ON
SF11FM4:Knife-edgePlay Trackfm_knedg---
SF12FM3:Auto HoverPlay Trackfm_hover---
SF13FM2:Auto LevelPlay Trackfm_level---
SF14FM1:StabilisedPlay Trackfm_stab---
SF15FM0:NormalPlay Trackfm_norm---

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Categories: OpenTX Tutorials