x4r

[Kilrah]

That's what would happen if your receiver is an X4R-SB, which provides an SBUS signal on the 4th connector instead of a servo signal for channel 4.

[Parts]

Thanks
How do I set this up for thr, ail, ele and rud with a vairo in SPort

[MikeB]

You need a SBUS decoder on the "channel 4" (SBUS) output to get the 4th servo output.

You just connect the vario to the SBUS connector.

Mike.

[jhsa]

I find that a bit stupid?
Why didn't they just implement the use of a jumper between channels 1 and 3 to output SBus on channel 4?
That is absolutely ridiculous? A 4 channel receiver that only outputs 3 channels, and needs an Sbus decoder to make use of channel 4,
I don't know what they were smoking when they designed the receiver, but for sure I wouldn't smoke the same

João

[Kilrah]

They sell 2 versions with either CH4 or SBUS, if you know you need the 4th channel you'd buy the X4R, not the X4R-SB.

You can easily convert them if you're into DIY.

[jhsa]

If I'm into diy I don't have to buy receivers, I build them
If they made 2 versions, then they could have made the SBus versions smaller without the other pins as they are useless anyway. Or, they could have designed only one where:

1 - We bridge 2 pins to get Sbus output on another pin (that is how the DIY receivers work).

2 - they could have put an extra pin/connection on the receiver for Sbus and keep all the 4 channels.

Some people just need 4 channels and expect a 4 channel receiver to have 4 channels.
Still think it is stupid
João

[michel49]

You can use a S-Bus servo as 4th. channel

[jhsa]

Well a small 4 channel foamie model might need only 4 channels. I certainly wouldn't like to have to buy an expensive ( and probably too big and heavy) sbus servo for a simple 4 channel foamie.. you shouldn't have to go around things when there is the possibility of making things right from the beginning on a commercial product. It makes me think they only do this so people have to buy other products to be able to get full functionality of the first one. And that is one of the reasons why I don't normally use known brands. Open source and DIY it's another story.. Things can always be made better

João

[MikeB]

If you want 4-channels you get the X4R, not the X4R-SB. The X4R-SB is actually a 16 channel receiver since SBUS outputs all 16 channels. If you are into quads etc. then your flight controller may well accept SBUS.

To change from 3 channel+SBUS to 4 channel involves moving a 0 ohm resistor from one place to another.
Bolt RC have a blog showing how to get 4 channels AND SBUS out together.
FrSky have optional firmware that outputs CPPM on channel 1, with 3 channels on the other 3 outputs.

Mike.

[Parts]

Guess I should have done my home work. Now I know
Thanks to all

[jhsa]

To change from 3 channel+SBUS to 4 channel involves moving a 0 ohm resistor from one place to another.

That is acceptable in open source and DIY stuff, not on a commercial product as not everybody can solder SMD resistors
That means people will really have to do their homework, and many will buy the wrong stuff. I think will see many issue reports about that here
I'm don't intend bashing frsky, far from it, I just mean that they could have done a much better job with this receiver. And if they wanted to make 2 receivers, then they could have designed a really small one ONLY with Sbus and/or PPM output. No extra pins. Multirotor people would have liked that A LOT, specially guys that are into quad racing or mini quads in general..

João

[MikeB]

This is the pdf that shows how to swap between using SBUS and using 4 channels on the X4R(-SB).

Mike.

[jhsa]

Thanks Mike, From the pdf file you have posted.

3.If the resistor is soldering on the place of R34, the 4th pin would output PWM signal of
channel 4. You can move the resistor to R35 and the 4th pin would output SBUS signal.

Would it not have been better if instead the procedure was??:

Bridge CH1 and CH3 signal pins at power ON for an SBus signal on CH4.

No need for 2 receivers then, you would just select which mode you wanted at power ON. I'm quite positive that this could have been done in the software.. That is how the DIY receivers work and I find it much better.. But that is just my opinion.
I think there might be some marketing reasons why they have decided to do it this way..

João

[MikeB]

If you have to bridge two channels to get SBUS, then you lose those two signals as normal servo outputs.
Too many different ways of doing things!
With the way they have done it, you can get at the SBUS signal and still have FOUR servo outputs if you wish.

Mike.

[PNaz]

João. I have used the unique capabilities of the X4R-SB for a GWS Cargotrans. It has 4 small outrunners with esc's so 1 esc is plugged into ch1 for left outboard motor , 2 esc's with y harness into ch2 for the inboard motors, and 1 esc into ch3 for the right outboard motor. This way I can simulate an engine failure with a feathered prop due to brake set on esc in either outboard motor. The 6 amp esc's and outrunners are similiar weight to the original brushed motors and controller but have more power. All flight controls (2 ailerons, 2 flaps, 1 elevator, and 1 rudder) are controlled by 6 Corona 6gm s.bus servos. The 2 flap servos are the only significant increase in weight from the original setup. It hasn't flown yet but it all works on the bench.

Paul

[jhsa]

If you have to bridge two channels to get SBUS, then you lose those two signals as normal servo outputs.
Too many different ways of doing things!

If you are using SBUS, very unlikely you will be using Cannels 1 3 and 3 for anything else as you get everthing on the SBUS signal anyway.

With the way they have done it, you can get at the SBUS signal and still have FOUR servo outputs if you wish.

I would think you will have the sbus output and THREE servo outputs??

The only situation I can see that people would want to use SBUs and servo outputs is to use one of the frsky sbus servos.
There are 2 situations you might want SBUS as far as I know.
One is to connect to a flight controller that also normally manages any other servo in the aircraft. If it doesn't then Channels 1 to 3 will also be useless as the flight controller normally uses them for controlling the model.

The other situation is if you want to use SBUS servos, which leads to my opinion about the marketing subject

João

[jhsa]

João. I have used the unique capabilities of the X4R-SB for a GWS Cargotrans. It has 4 small outrunners with esc's so 1 esc is plugged into ch1 for left outboard motor , 2 esc's with y harness into ch2 for the inboard motors, and 1 esc into ch3 for the right outboard motor. This way I can simulate an engine failure with a feathered prop due to brake set on esc in either outboard motor. The 6 amp esc's and outrunners are similiar weight to the original brushed motors and controller but have more power. All flight controls (2 ailerons, 2 flaps, 1 elevator, and 1 rudder) are controlled by 6 Corona 6gm s.bus servos. The 2 flap servos are the only significant increase in weight from the original setup. It hasn't flown yet but it all works on the bench.

Paul

Yeah, your application is a good idea, and probably one of the very few (if not the only) situations where that might be useful..
Normally sbus is used with flight controllers which make channels 1, 2 and 3 useless on that receiver..
Ahh, and you can only do that because you have probably a radio with open source firmware on it, where you can use the channel order you like. With most of the conmmercial radios with an XJT module on them you wouldn't be able to do it. So, yes, they could have done it better

João

[MikeB]

I referred to this above: https://boltrc.com/blog/x4r-sbus-mod-how-to/.
How to get the SBUS signal out while still having 4 servo outputs.

Mike.

[jhsa]

I referred to this above: https://boltrc.com/blog/x4r-sbus-mod-how-to/.
How to get the SBUS signal out while still having 4 servo outputs.

Mike.

true, I forgot about it, sorry and thanks.. But wouldn't it have been nicer if they would have placed at least one more pin on the receiver board? Then no need for 2 versions of the receiver And no need for people to DIY

João

[Kilrah]

And if they wanted to make 2 receivers, then they could have designed a really small one ONLY with Sbus and/or PPM output.

That's the XSR, but it came a year later. The X4R was a "quick" design based on what they already had for the D4R-II, it's clear they didn't want to lose too much time doing a major redesign but they correctly identified having an SBUS version right now as being important. The customers for each being quite different it wasn't a problem to have 2 separate versions, just pick the right one for your scenario.

[jhsa]

That is the problem, many will pick the wrong one
Ok, I just wanted to give my opinion, that's all If I don't like it, I don't buy it it is as simple as that
As I said, I don't intend to bash anything or anyone, just found this quite strange

João