Futaba SBUS to PPM? FrSKY to the rescue!

For months now I've been looking for a SBUS to PPM converter for my Futaba Radio. I want to place my Futaba RX out on one wing and my video TX on the other. While surfing FrSKY's page for a SBUS receiver I ran across a SBUS to PPM converter! I've seen plenty of DIY converters but Aloft hobbies had one cheap in the states and ready to go for about $15. 

After reading around in a few forums I was a bit skeptical about it working. After checking things out in Mission Planner things look good! Now I can finally rip the 10 wires out of the wing and narrow it down to three!

Hopefully this helps other folks looking for a SBUS to PPM converter. I won't miss the rats nest of wire I had before. 

Views: 21404

Comment by Greg on August 12, 2013 at 6:44am

One thing that might be cool with this setup is you might be able to also use the PWM ports for other, non autopilot things. (i.e. 8 channels for autopilot, 8 channels for other things like camera controls, gimbal, undercarriage etc, etc = 16 channels).

Am I reading the specs correctly? See bullet point 2. (Actually they quote 18 channels, maybe SBUS has an extra 2 channels?)


Comment by FD on August 12, 2013 at 8:05am

Hi all, have a look at this Delta-8 Receiver (obviously built on FrSky Hardware): http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=42310

It is compatible to a lot of protocols, including S-FHSS that my Futaba T8J uses and RSSI and CPPM. Nice.

There is a thread on RC-Groups if you like to know more: http://www.rcgroups.com/forums/showthread.php?t=1874908

Comment by Scott Fuller on August 12, 2013 at 8:45am

John, Agreed. Futaba went out of their way to make this their own protocol. It seems the rest of the industry has adopted PPM as the standard leaving Futaba users out. 

Dror, sometimes going back to the archaic technology is the easiest route. *sarcasm* NASA is going back to capsules after all /sarcasm. I'd love to see the APM speak SBUS natively as I'm heavily invested in SBUS from my sport flying days. Something like move the jumper to output pins 2-3 instead. I've seen patches that allow APM to speak SBUS but that seems more error prone as it's not in the current release. The excitement comes when I can rip a hefty CAT-6 cable out of my plane and replace it with three wires. 

Greg and FD - Don't know if you guys have seen the TFR8S RX from FrSKY but it's something I've been keeping an eye on...


You can 'stack' the receivers to give you up to 14 channels. You figure 1-8 would go into the APM and the remaining channels you hook directly into. The other RX I've been look at is the TFRSP that gives you up to 10 channels. 


Comment by Willem Oldemans on August 12, 2013 at 11:03am

I didn't look to good for cppm option when ordered my frsky Taranis wit X8R receiver, it only has 16ch sbus and 8x ppm out. I received my sbus<->cppm a few day's ago, works like a charm! and by the way, the Taranis is awsom!

Comment by Pbreed on August 12, 2013 at 12:43pm

I've switched all my (custom not APM based) stuff over to Spektrum using the satellite receivers directly sending async serial easy to use and a lot less wires... if you want redundant receivers you just need more serial ports...

(My current CPU has 10... so I have lots of these).

Much simple than messing with multiple pulse channels from a receiver... 

Comment by Nathaniel Caner on August 12, 2013 at 2:24pm


The 6208SB receiver can handle as many as 18 channels when using S-Bus up to the number of available channels for your compatible TX. In this case that's 14 with the T8FG in MLT/MLT2 mode. I have this transmitter/receiver combo and love it! Very easy to program and navigate once you get used to it. On my current airframe, a Super Sky Surfer, I use 11 channels.

1-Ailerons - To APM CH1

2-Elevator - To APM CH2

3-Throttle - To APM CH3

4-Rudder - To APM CH4

5-Pan (FPV Camera) direct to Pan Servo via S-Bus

6-Tilt (FPV Camera) direct to Tilt Servo via S-Bus

7-Geo-Fence Toggle Switch - To APM CH5

8-Mode Switches (two switches mixed for 6-modes) - To APM  CH8

9-Mission Reset Momentary Toggle Switch - To APM CH6

10-Flaps direct to Flap Servo via S-Bus

11-MinimOSD Panel Select 3-POS Switch - To APM CH7

The System Works perfectly so far. I would love to go to a PPM sum receiver, however I'm not sure if I could take advantage of all 14 channels of the T8FG with a PPM sum receiver as it requires the use of MLT/MLT2 mode to get the extra channels. Otherwise in 7-CH mode you only get......7 channels. I also don't want to send all (nor can I) the channels to the APM; I.E. pan, tilt and flaps (though I wouldn't mind if the APM supported it!

All in all it's a great TX!


Nathaniel ~KD2DEY

Comment by Graham Pollock on August 12, 2013 at 4:28pm
Why would you need this: what is SBUS?

Comment by Nathaniel Caner on August 12, 2013 at 4:51pm

Hey Graham,

Basically S-Bus is Futaba's proprietary serial communications system. It allows you to assign an address to specialized S-Bus compatible servos or using addressable/programmable hubs with conventional servos. This gives you the ability to do some cool things, like say having multiple servos in the tail of a plane while only running a single cable all the way from the receiver in the front then distributing the signals to the individual servos. Also you can plug a battery in at any point on the system allowing you to place the battery closer to the servos that need the power, or perhaps placing the battery where it can help balance the plane without adding longer leads.

Check this out on Futaba's site for a better explanation of the capabilities.


Nathaniel ~KD2DEY

Comment by Caleb Phillips on August 12, 2013 at 4:51pm

I used a cheap ($.20) hex inverter to read multiple Futaba sBus signals into an APM for a project at work. It was really easy to do and the signals are much cleaner than what comes out of the APM ppm converter. 

Comment by Nathaniel Caner on August 12, 2013 at 4:53pm


Got a link? And is that 20¢ or $20? Hard to read if that's a decimal in there. I'd like to hear more about this.


Nathaniel ~KD2DEY


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