XHT Module w/ two Receivers D16 mode?

[Neutrahaus]

Has anyone managed to pair an XHT module in D16 mode with two X8R modules to simultaneously use ch1-8 and 9-16 respectively? I tried bridging the signal pins 1-2 and 3-4 on the second receiver and no luck binding the 2nd on top so far. Thanks. Instructions are somewhat cryptic. This is for a robotic STEM learning project. [ I only fly 2 channels… old school Hobie Hawk ]

I’d consider alternate hardware solutions as needed, but require use of a Tx module… no room for a full sized Transmitter onboard.

Thanks Folks.

 

[Wayne]

What firmware are on the X8R? I think you will need the older ACCST V1 for this to work on the X8R.

@MikeB - Do you recall if X8R Uni supports this binding method via the jumper?

 

[MikeB]

UNI does not support selecting 1-8 or 9-16 using link options. Normally this is selected on the Tx when binding, but this won't work in PPM mode.

Mike

 

[MikeB]

Perhaps we need some more information on your actual requirements.
Where is the XHT?
What is driving the control input to the XHT, is it using PPM?
Why do you need two X8Rs, and where are these situated?
The X8R has a SBUS output that provides all 16 channels. A simple SBUS decoder could provide all 16 PWM channels. I have an Arduino project that uses a Pro MINI and provides all 16 channels, see here: https://github.com/MikeBland/SbusToPWM

Mike

 

[Neutrahaus]

Mike, Wayne… thanks for your expertise. The X8R receivers are ACCST and just as they come out of the box. No idea what firmware version. The XHT is operating in a briefcase receiving input from a RIMILEC PWM to PPM converter (green wire into the XHT. It “sees” the servo outputs from a robotics board and passes the PPM to the XHT Tx. This works for ch1-8, one receiver.

That’s a fascinating solution MikeB. I hadn’t thought of using the Sbus output of just the one receiver. I presume that output is always-on by default? Funny, I think I saw your GitHub when I was research how to do this a year ago!

But argh! here’s the problem… I’m trying to use one XHT to two receivers because each receiver is in a separate wireless robot… thus the double binding direction.

I hope this clarifies the situation. Thank you again for your input(s)!

 

[Neutrahaus]

I have an Arduino project that uses a Pro MINI and provides all 16 channels

But this is so genius for future projects…What kind of delay do you get running all 16 analog channels out of the Arduino?

 

[MikeB]

As soon as the SBUS data has been received, channels 1-4 are sent out, when complete, channels 5-8 are sent, then 9-12 an then 13-16. The pulses are only sent every 18mS.

I've run some tests using a XJT and a X8R.

If the XHT and X8Rs have V1 firmware then binding using the link options works as specified.
If they have V2 firmware, then the output channels and telemetry are controlled by settings stored in the XHT, the links are ignored. These settings are set when binding using the PXX protocol (not PPM).
If a bind is attempted when using the PXX protocol, the channels and telemetry are set in the module, and these are then used when binding using PPM and the bind button.

So, if you bind one receiver as currently, then connect the XHT to a Tx that supports the PXX protocol and attempt a bind using the 9-16 and no-telemetry options, then reconnect the XHT as you require, then all subsequent binds using PPM and the bind button will set channels 9-16 and no telemetry on the X8R. To revert to 1-8 and telemetry will require the XHT to be connected to a Tx running PXX protocol and a bind attempt made using the appropriate settings.

Mike

 

[Neutrahaus]

So, if you bind one receiver as currently, then connect the XHT to a Tx that supports the PXX protocol and attempt a bind using the 9-16 and no-telemetry options, then reconnect the XHT

Ah! I have a Tarranis X9D Plus on hand and will give that a try. Will report back of course. Thank you MikeB “The Protocol Whisperer”!

 

[MikeB]

I'm probably been making this a bit more complicated than necessary!
Connect the XHT to the Taranis external connections. From top to bottom the module bay connections are:
PXX/PPM
Heartbeat
Positive supply
Ground
SPort.

Set the external module protocol to PXX, 16 ch, then bind each receiver with the required settings e.g. CH1-8 and telemetry on one, and CH9-16 and no telemetry on the other.
The receivers are now bound to the XHT in the modes you require. Using the XHT with a PPM input from something else will then NOT need binding again.

Mike

 

[Neutrahaus]

So, if you bind one receiver as currently, then connect the XHT to a Tx that supports the PXX protocol and attempt a bind using the 9-16 and no-telemetry options, then reconnect the XHT

Ah! I have a Tarranis X9D Plus on hand and will give that a try. Will report back of course. Thank you MikeB “The Protocol Whisperer!

I'm probably been making this a bit more complicated than necessary!
Connect the XHT to the Taranis external connections. From top to bottom the module bay connections are:
PXX/PPM
Heartbeat
Positive supply
Ground
SPort.

Set the external module protocol to PXX, 16 ch, then bind each receiver with the required settings e.g. CH1-8 and telemetry on one, and CH9-16 and no telemetry on the other.
The receivers are now bound to the XHT in the modes you require. Using the XHT with a PPM input from something else will then NOT need binding again.

Mike

 

[Neutrahaus]

Hmmm… didn’t work. 2nd Rx wasn’t bound when the XHT was powered up disconnected from the Tx. I then tried re-binding the 2nd Rx with the XHT module detached. This made the 2nd Rx bind to ch1-8. I will try again.

Should the jumpers be used on the signal pins 1-2 & 3-4 of the 2nd Rx to set ch9-16 during either binding with the Tx or later detached from the Tx with the PWM->PPM converter?

fwiw, I did not see a PXX mode on the X9D Tx but set it to:

Ext RF Mode: XJT D16
Ch Range: 1-8
Receiver: 00

(then after)
Ch Range 9-16
Receiver 01

Perhaps I should have just set it to
Ch Range 1-16
Receiver 00

???

Or maybe I need a firmware upgrade from 2.3.11-otx?

-Round 2-

Ok tried again. This time set the Tx to:
XJT D16
CH1-16
Receiver 00

Powered up the 1st Rx in F/S mode and it binds 1-8 and so I powered down.

Put the 2nd Rx in F/S mode and hit bind again on the Tx. It popped up a choice for 1-8 w or w/o telemetry or 9-16 which I selected. No telemetry for either set of 8. Now I have with the XHT still connected to the Tx bound green lights on both receivers, ch1-8 working on Rx #1, but Rx #2 not moving any servos mapped to ch9 or ch10 with the Tx… the left and right little potentiometers on the sides of the Tx, which show activity on the LCD display but not moving test servos on Rx#2. And should also mention Rx#2 does not react to mapped gimbals for 1-8. It feels close somehow!

Thank you very much for all the help!!!!

 

[MikeB]

What do you have in the mixer for channels 8 and 10?

Mike

 

[Neutrahaus]

What do you have in the mixer for channels 8 and 10?

No mixing set up for those channels from what I can tell. See pics below. The ch1-16, Receiever 00 shown, though i tried it as two receivers 1-8 on Rx00, 9-16Rx01. That resulted in un-binding Rx 00 when I changed it to Rx01. I feel like your mixing question is close to a solution because the 2nd Rx looks and feels ready… test servos receiving a positional pulse but don’t wiggle with Tx sticks nor activity through the pwm-ppm converter when the XHT is detached from the Tx. Can’t speculate on whether that’s the input of the module on 9-16 or an output issue. I think I tried binding the 2nd Rx with the two jumpers and also without which resulted in the same behavior. Feels like a mapping issue somehow, but I’m certainly a newbie.

Edit: Interesting. I’m not seeing any response on the LCD when moving the side pots for ch9-10 in CHANNELS MONITOR but I do see slider movements on the main model display on the sides.

Appreciate your generosity and patience, MikeB.

 

[MikeB]

In openTx (and other open source firmware e.g. erskyTx), everything is a mix, there are NO outputs on any channel by default. If you don't have a mix on a channel, then it will be in the centre position.
Just add a mix on each of channels 9 and 10, try a source of SL and SR, then the sliders at the side should control channels 9 and 10.

Mike

 

[Neutrahaus]

Excellent. Of course now I feel old and dumb. This sure ain’t a Kraft brick. I have movement on ch9-16, both Rx’s paired and discreet. I will wire it back into the briefcase with the PWM-PPM and cross my fingers that this channel enabling “sticks”. I suppose there’s an eeprom or similar in the XHT module which stores some settings data? Do all those additional settings in openTx for servo limits, speed, etc etc get burned in the module as well? Would they also be set with generic ppm data input? That could be very handy for tuning these robotics projects!

Hah! To do a mixer for flying wing slopers we used to use a servo to slide the aileron servo on a sled. Changed the CG in the right direction too!

 

[Neutrahaus]

Holy Pulse Width Modulation, Batman!!! It WORKS!!!

One stand-alone XHT module receiving PPM binding to two X8R receivers, 1st doing ch1-8, 2nd doing ch9-16.

Curious about which settings will be saved using this technique, but for the moment I don’t want to touch anything!

Also, for the future, could an XJT module or other set of gadgets be used as easily? PWMtoSbus maybe? I’m concerned about the XHT having been discontinued. The only restriction in my setup is starting with PWM on the TX side, and ending with 8+8 PWM servos in two wandering bots.

MikeB, the B must be for BRILLIANT!

Thank You.