Hello guys,

is it possible to use PPM and PWM outputs simultaneously with the Flysky receivers? I'm currently trying to get the FS-X6B receiver working with my DJI F550 (Naza M V2). Unfortunately Naza doesn't support IBUS so I'm using PPM with 8 channels which seems to be enough for me  at the moment (4ch for hexa control, 2ch for gimbal and 1ch for flight mode switching). But there also is a retractable landing gear that only has a PWM input. I prefer to use PPM for simpler wiring to the FC, so if it would be possible to use PPM for everything and one PWM output just for the landing gear simultaneously it would be best option for me than buying other RX with 10 PWM channels and using PWM only.

Thanks.

you still have one channel. why not use it?

Thanks - ok, I'll try to explain it better...

Flysky FS-X6B provides 6ch PWM / 8ch PPM / 18ch IBUS. I use the 8ch PPM using one wire connected with the Naza FC (because it does support only SBUS or PPM - not IBUS).

The retractable landing gear has its own 3-pin PWM input. There also is a gimbal, which means 6ch PWM is definitely not enough for my needs. So I'm looking for solution in the way of using simultaneously 8ch PPM for the F550 + gimbal control and 1ch PWM separate output for the landing gear with the X6B receiver if possible as I know for example that FrSky receivers provide this option.

So far the only solution I've found out would be using a 10ch PWM receiver (Flysky iA10B) and use PWM only for everything, but I'd like to avoid that if possible to keep wiring clean and simple (and need of buying a new RX as well).

I still don't quite understand. You should have PPM from RX to Naza on X2 on one wire. On the Naza output, you have 8 channels. M1-6 and F1-2. You stated 4 channels for control, 2 for gimbal and 1 for flight mode = 7 channels. You still have F2 left on the output. That is PWM.

One picture is better than thousand words  

   

The only outputs from the Naza FC are M1-M6 which are all used for ESCs (F550 is a hexa) and F1+F2 outputs are used for gimbal axis (F1 for roll, F2 for pitch) which means there is no output left. So I'm looking for the RX-side solution. Or did I get something wrong?

In your OP, you mentioned 4ch for control, 2ch for gimbal and 1 for flight mode. I didn't pick up that hex which uses 6 channels. Ok, I get it now.

Back to your, question. Since the Naza is limited to 8ch outputs total, it really doesn't matter if you have 18ch from your RX through IBUS. You don't have available PWM on the FC, which is the limiting factor. Unfortunately, you cannot use pwm 2-8 alongside with PPM.

If you want to use RX PWM mode (messy wiring which you are trying to avoid), you might be able to bind two receivers at once. I don't know if this is possible for Flysky. I know it is possible with Frsky, which I know does not help you. You don't have much options due to the FC.

I'm sorry as still I'm kinda new to the hobby, so maybe my terminology and of course overall knowledge is at the beginning level so I might give you bad information


I meant 4ch is required for controlling the hexa movement by the TX (which should be the same as by the quad - pitch, yaw, roll, throttle). Honestly I just ignored the Naza FC outputs as I know all of those are already in use so I can't use them for this purpose. But I forgot to mention that...


Ok, so final solution looks like using the 10ch PWM RX is the only option...

No problem.

Still back to the original post - does anybody know if there's any way how to get PPM + PWM working simultaneously? I know this is possible with FrSky RXs. On some other forum I've found and older post mentioning that this can be done with Flysky X-series RXs (which X6B is), but nobody mentioned there how exactly does it work and nobody confirmed that information

And Flysky simply doesn't respond to my question.

Thanks.

Alright,I decided to go with Taranis... ?

Ok, my Taranis X9D+ just arrived with X8R receiver. So later I'll be trying to find out how to set it all up to suit my needs. With Flysky everything was pretty straightforward, I'm not sure if it will be the same with Frsky...

Before I start - as the Taranis is a used one, what should I do first of all? I've been thinking of some kind of factory reset and updating firmware to latest? Any links for this would be appreciated.

Now about the X8R binding. As I mentioned, I need at least 8 channels SBUS (9 or 10 would be even better) to control the F550. One PWM output with +5V voltage would be enough for the retractable landing gear in case I'll use the Naza FC to control the gimbal. I assume I could connect PWM outputs from the RX to the gimbal directly, but Naza provides some kind of trimming for this purpose (not sure if it's needed).

Not sure if I got this right, but so far I understand it's only possible to use 8 channels SBUS + 8 channels PWM when using these simultaneously (as PWM channels become CH9-16 while SBUS is CH1-8 right?).

If it's like that, I'll use direct PWM connection from the RX in case 8 channels won't be enough for the drone itself.

Could you please help me and recommend correct RX/TX binding and settings for this setup?

May I use the PWM output from the X8R even for the retractable landing gear power supply (+5V, max. 200mA) or do I have to find the power supply elsewhere? Is it safe to use X8R for this?

Thank you guys very much, any help is appretiated.

Do NOT connect the landing gear directly to the X8R, it requires full lipo power. As for simultaneous s-Bus and PWM, you need to put a jumper across signal pins (top pins) 1 & 2, and 3 & 4 on the X8R, then bind as usual. For a more detailed explanation, go to Youtube and do a search for: FRSky X8R 16 channel

Thanks, that's what I've been a bit scary of... OK, so now I have to find out where to get another +5V output for the landing gear on the DJI F550...

I have this VR on my 650 Sport and use it for a number of different accessories
https://www.readymaderc.com/products/det...-regulator

Good idea, how could I forget about using a stepdown regulator...  

Thanks!

So far I've been looking for the Naza specs I but still I'm not sure about using it for this purpose. Naza FC is powered via PMU unit which is connected directly to LiPos.

In this manual DJI writes (page 5):

Quote:V-SEN: Connect to Main Controller X3Port
Important: the continuous output of the
PMU is 3A@5V, and the maximum
instant current is 7.5A. If PMU cannot afford
the working current for your servos, please
use an independent power supply; otherwise,
it may cause the PMU safeguard and lead to
the main controller reboot

So the PMU can deliver a maximum of 7.5A current. Not sure how much does the FC itself consume. There's also a GPS module, LED module and BTU unit connected (every of these has its own separate port on the PMU unit).

But hopefully I could simply give it a go? As mentioned in the manual, if the current drain will be too much, it will cause PMU to restart so there shouldn't be any kind of damage to any electronics, right? I know, things can happen, but shouldn't, right?

Of course if PMU restarts, it will probably cause the F550 to crash, so I'll test it in low altitude just above the ground.

What do you think? Still considering this option as I'm pretty sure Naza should handle this without need of any other stuff or not?

Thank you very much.

I'll take a couple pics of my wiring setup after work but it's basically 2 power supplies:

Your MPU is connected to your lipo and powers your flight controller, GPS & LED status indicator.

The voltage regulator is also connected directly to the lipo and is used to power everything else such as FPV system (if you have one), landing gear, OSD, BTU, LEDS, etc.

On a side note, I just stumbled across this Matek UBEC which looks far superior to the RMRC unit. Pretty cool that it has a switching AUX, would be great for turning LED lighting on and off
https://hobbyking.com/en_us/ubec-duo-4a-...4a-5v.html