Simple Taranis X9D+ Wireless Trainer Using SBUS Receiver Input

Introduction: Simple Taranis X9D+ Wireless Trainer Using SBUS Receiver Input

About: Drones & 3D Printing

The goal of this project is to connect a FrSky X-Lite transmitter to a FrSky X9D+ transmitter in a TRAINER configuration using a cheap SBUS receiver (12$). By connecting the two together in this way, it is possible for an instructor pilot using the X9D+ to pass control of one or more channels to a student pilot using the X-Lite while a switch is held. By releasing the switch at any point, the instructor can regain control of the model and recover in the event that the student pilot loses control.

Since the X9D+ does not support the FrSky wireless trainer system and the X-Lite does not have a trainer jack for connecting a trainer cable, we are going to BIND the X-Lite to an SBUS compatible receiver connected directly to the pins in the module bay of the X9D+ in order to pass channels 1 to 4 from the SLAVE radio to the MASTER radio.

Step 1: THINGS YOU NEED

  1. MASTER RADIO: FrSky X9D+ Transmitter (REQUIRED)
  2. SLAVE RADIO : ** FrSky X-Lite Transmitter
  3. SLAVE RECEIVER: ** FrSky XM or XM+ Receiver
  4. 5 Position Header

** Although I used the FrSky X-Lite transmitter and XM+ receiver as the SLAVE radio and receiver, any transmitter/receiver combination should work provided that the receiver is SBUS compatible and bound to the SLAVE transmitter. If you decide to use a different receiver, take note of the pin mapping and ensure the receiver can handle up to ~8.4V input.

Step 2: BINDING THE TRANSMITTER

* This instructable assumes that the MASTER radio (X9D+) is already bound to the RC model/drone/airplane that you plan on flying. If that is not already the case, please look up the instructions specific to your receiver (or, if the receiver in your aircraft is also a FrSky XM or XM+, follow the steps bellow for the aircraft receiver first) *

Before we do any soldering or connect anything up permanently, it is best to BIND the SLAVE receiver to the SLAVE radio since the BIND button will be difficult to access later. Follow these steps to BIND the XM+ receiver to the X-Lite transmitter:

  1. Turn on the X-Lite, create a new model called 'TRAINER', select D16 receiver and BIND (CH1-8).
  2. While holding down the BIND button on the receiver, power it up using any 5V source or using jumper wires to the VBAT and GND pins in the module bay of the X9D+.
  3. A RED flashing led indicates BIND complete, disconnect the power to the receiver
  4. Disable BIND mode on the transmitter
  5. Power up the receiver and transmitter normally, a GREEN led confirms a good connection with the transmitter

Step 3: SOLDERING THE HEADERS

One advantage of using the FrSky XM or XM+ receivers is that the solder pad spacing and order is the same as the pins in the module bay of the X9D+. This means we can solder headers to the receiver and plug it directly into the back of the X9D+ with no wiring or other circuitry required!

You will notice inside the module bay there are a total of 5 pins, pay close attention to which ones we are using and which order they are in. In order to prevent accidentally plugging the receiver into the wrong pins, we will be using a 5-position, 2.54mm spacing header that can be easily cut from one of the strips linked previously. Using pliers, remove the metal contacts from the outer 2 pins and notch the plastic of the 5th position using a hobby knife such that the LED of the receiver is still visible after soldering. Finally, solder the receiver to the center 3 of the 5 positions with the female header facing the same side as the bind button and LED as shown.

Step 4: PLUG IN THE RECEIVER

With the X9D+ turned off, plug the receiver into the module bay as shown. Before powering up the X9D+, confirm one last time that the receiver is indeed on the center 3 pins and the BIND button and LED are facing down as shown. If the receiver is on the wrong pins, you may damage it.

Step 5: ENABLE SBUS TRAINER INPUT

  1. Make sure the you have the latest OpenTX firmware (at least v2.2) installed on your X9D+
  2. Power up the X9D+
  3. Go to model setup page (MENU > [Select Model] > PAGE)
  4. Under 'Trainer Input' select MASTER/SBUS

Step 6: CONFIGURE TRAINER CHANNELS

We will be configuring the trainer channels much in the same way as described here. For more information on the different settings, please visit Sean Cull's page.

  1. Turn on both radios
  2. On the X9D+, navigate to the TRAINER menu (long press MENU until RADIO SETUP appears then press PAGE 3x)
  3. If everything has been done correctly up until now, when you move the sticks on the X-Lite the values at the bottom of this page should change accordingly, if everything works, configure the channels in pass-through mode (:=), adjust the scaling as required and go to the next step.

Troubleshooting: (values not reacting to SLAVE stick input):

  1. Verify the receiver is powered and bound to the X-Lite (GREEN LED).
  2. Verify channels 1 to 4 on the X-Lite are mapped to the sticks using the CHANNEL MONITOR page on the X-Lite.
  3. Verify the receiver is connected to the center 3 pins of the module bay in the correct order.
  4. Verify trainer mode on the X9D+ is set to SBUS-MASTER

Step 7: CONFIGURE HANDOVER SWITCH

Now we will assign a special function to a switch on the MASTER radio so that it will hand over control to the SLAVE radio while pressed. Navigate to the SPECIAL FUNCTIONS page on the X9D+ by pressing MENU > PAGE (x9) and configure your switch of choice as shown.

Step 8: FINAL CONFIRMATION

With everything configured you should now be able to open the CHANNEL MONITOR page on the X9D+ and see the channel values change when the sticks are moved. When the previously assigned switch is held down however, the channel values should change according the sticks of the SLAVE radio instead.

Step 9: BONUS POINTS - 3D PRINTED ENCLOSURE

Although the receiver and its antennas fit just fine behind the module bay cover on the X9D+, it is possible to take this project one step further with a 3D printed enclosure that snaps right into the module bay and makes it even easier to swap in and out as needed.

See the enclosure that I designed here! All that is required is (6x) M2x8 flat head screws for the cover which can be found here. The enclosure fits snugly around the headers and the lid holds the receiver module in place.

Enjoy your new trainer system with a friend!

5 People Made This Project!

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38 Comments

0
FrankL73
FrankL73

3 months ago on Step 5

Just to echo the findings below, S.Bus is not working June2021 on new ACCESS protocol (QX7) master transmitter but works with ACCST protocol master transmitter. For this robotics project I had to switch to and older Taranis -Plus Tx & Rx. Also, voltage was not required from my PWM-S.Bus (RMILEC) converter and the module's voltage pin on the back of the transmitter... just S.bus and shared ground. fwiw I tried both PPM and S.Bus with the latter being noticably quicker. But that's well documented on the r/c sites.

Tx.jpg
0
Vector3D
Vector3D

Reply 3 months ago

Thanks for the info!

0
JohnHennesey
JohnHennesey

Question 7 months ago on Step 3

Very cool! Anybody think it will work if I have a spektrum dx6i transmitter as the student, and if I get an OrangeRx Dsm and program it to output sBus? I would think sBus output from any receiver should put out the same signal, right? [OrangeRx default output is Spektrum1028|2048 - a programming card can change it to sBus]

0
Vector3D
Vector3D

Answer 7 months ago

Any receiver that can give you SBUS output should work just fine. Let me know if you get it working!

0
JohnHennesey
JohnHennesey

Reply 7 months ago

Success! I purchased an Orange 620x Version 3 and an OrangeRx Program Box and took the following steps:
* bind the Orange programmer to the 620x
* change the 620x output to sbus
* bind my spektrum dx6i to the 620x
* Took a female to female 3 pin standard servo wire and connected the three middle pins [ground bottom, battery middle, and sbus top] to the bind / channel 1 of the 620
* follow the steps to set up a model on the x9d as a trainer
* go to the trainer screen on x9d - and see the values move as I move the dx6i controls

Thank you so much for this instructable - not only did it answer my curiosity of what the pins in the x9d module were for, it saved me from buying yet another radio!

John

0
Vector3D
Vector3D

Reply 7 months ago

That's great news! Thanks for sharing your success.

0
pH7_JP1
pH7_JP1

Question 8 months ago on Step 5

On my Radiomaster T16s running OpenTx 2.3.9 the only options for Trainer are: Master/Jack, Master/Serial, and Master/Multi - No Master/SBUS Module option. Also, there does not appear to be power to the BATT pin. Any suggestions will be appreciated.

0
Vector3D
Vector3D

Answer 8 months ago

Thank you for your interest in this project, unfortunately user @tdevos had experienced a similar problem with his T16 further own in the comments. I personally don't own a T16 but considering the S in SBUS stands for serial I would give Master/Serial option a try. Let me know if it works! Good luck.

0
pH7_JP1
pH7_JP1

Reply 8 months ago

I did try serial with no result. In Companion 2.3 the options for Trainer Mode are: Master/Jack, Slave Jack, and Master/Multi. There are several other options that are grayed out: Master/SBUS Module, Master/CCPM Module, Master/SBUS in battery compartment, Master/Bluetooth, Slave/Bluetooth. I suspect that the Bluetooth options would be available if the build option for Bluetooth is checked, so I wonder if any of the other build options would enable SBUS Module, but I have been unable to get much information on the build options.

0
stlucia2
stlucia2

Question 1 year ago on Step 6

I'm trying to build this project using a Taranis X9D+ 2019 with EU LBT v2 firmware as Master, and a Taranis X9D+ with EU LBT v1 firmware as Slave. I have a FrSky XM receiver which is bound to my Slave transmitter, showing a solid green LED. I have plugged it into the module bay pins of the Master Tx as per your diagram and, with all screens configured as per your descriptions and pictures, I get power to the receiver (a red light) when I switch the Master Tx on, then a bind (green light) when I switch the Slave Tx on. So something's working!

But after verifying that the Slave sticks are working correctly in its channel monitor I still get no response in the Master channel monitor -- either before or after I've configured SH to activate trainer mode. All is correct as per your final checklist, so I'm beginning to wonder if the pin next to the Batt pin in the module bay is in fact an SBus pin, for there's several diagrams on the internet that show it as a 6v pin.

More likely I've missed something very simple. Any ideas please? I've already checked the pin in question with my DVM and it's showing 0.0v, so it's not a 6v pin.

Edit: I've been through the setup again, and have tried using an R-XSR receiver in both SBUS and CPPM mode (with the Master configured accordingly), and still no response in the Master transmitter. I've just read that the 'Linker' module, which does the same thing (and more) as this project, doesn't work with an ACCESS transmitter. Maybe that's the key to my issue. Tomorrow I'll swap my transmitters around, making the ACCST transmitter the Instructor, and see if that works.

0
stlucia2
stlucia2

Answer 1 year ago

Edit 2: Just swapped transmitters -- X9D+ ACCST is now Instructor, and X9D+ 2019 ACCESS is now Student, and it works as described in this how-to. So, unless my ACCESS Tx is faulty, I think I've proved that this project does not work with the Rx installed in an ACCESS transmitter. Thank you for the project.

0
ronron84
ronron84

Reply 1 year ago

i confirm it is not working on taranis x9d 2019. too bad, frsky is taking the wrong direction.

0
Vector3D
Vector3D

Reply 1 year ago

Glad you got it working, I would not have known what to do in your case. No problem, it's nice to see that by simply documenting what I did I am able to help others.

0
tdevos
tdevos

1 year ago

would this work on a Jumper T16 pro too?

0
Vector3D
Vector3D

Reply 1 year ago

If you were to flash the Jumper T16 pro with the latest version of OpenTX and double check the pins in the module bay are the same as the Taranis then it should work no problem. I personally have never tried but can't think of another reason that it wouldn't work. Good luck!

0
tdevos
tdevos

Reply 1 year ago

I can't find nowhere the bay pin put of the Jumper T16. But if accepts the Frsky DJT / R9 and Crossfire modules soI guess it will be same pin out of the Taranis.

0
tdevos
tdevos

Reply 1 year ago

hmm, story ends. There is no MASTER/SBUS option in the latest openTX firmware for T16. Only /BLUETOOTH /JACK /MULTI.

0
jims1234
jims1234

Question 2 years ago on Introduction

Vector3D,
As I mention below I got this to work in two Taranis Q7XS radios and it's working very reliably. .. but I wonder if it will also work with a TARANIS Master radio that can support TRAINER: MASTER SBUS mode, But with a non-Taranis Student Radio perhaps even non FrSky Type Student Radio if that Radio can Bind with the XM or XM+ Receiver? I think that is may .. do you agree?

0
Vector3D
Vector3D

Reply 2 years ago

It should work, so long as as the master is a Taranis and the receiver is either the xm or xm+ (or another SBUS receiver).

0
jims1234
jims1234

Tip 2 years ago on Step 9

Here’s something worth noting if you have trouble binding a new FrSky Receiver , or if you get a “No bottom pin response” error while flashing new firmware to a new Receiver via Tasanis SPort , you may want to try it again with this module temporarily removed. I found out this module can conflict due to a loading issue on the internal Module bay Pins unless you pull it out before doing these things..