Two of my customers have trouble setting up the Pixhawk - I myself have a Pixhawk, but don't use a Futaba receiver, thereby I can't replicate the problem (I would like to find out if the problem is connected to the receiver they use, or something else).

Both use a Futaba R7008SB receiver.
Both managed to upload the Firmware to their Pixhawks - but they are not able to do the radio calibration (the Pixhawk doesn't "see" the receivers, the bars in the calibration are all grey).

They have nothing else connected to the Pixhawk, except receiver (connected to the right port / RC), buzzer, safety switch and USB cable.

The Pixhawk signals via the big LED "pre-arm check failed" (which makes sense ;)

They power the Pixhawk via USB and at the same time with a LiPo (via the Power Module).

The receiver is "found" by the remote, the LEDs are on, the setting of receiver and remote (regarding the use of the SBUS) seems to be right. They use the right port of the receiver to connect to the Pixhawk.

I am happy about any suggestions ...

Thanks a lot in advance


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No problems at all Justin, glad to be able to help. It looks like a very nice build, you have a good machine there- have fun!

Thank you! I put a lot of thought into it. Here she is with the GPS mast we were talking about before.

Brilliant, that mast looks good- nice separation. You have done a good job of twisting esc wires, that will save a lot of issues and is quite often overlooked. One thing I have learnt, the most important thing is vibration (or lack of!). I had it demonstrated to me how a machine can be totally unflyable then rock solid, just by adding vibration dampening! Easy to do, just use a few vibration balls on your fc plate if you have not already. Been out flying our new prototype today in a howling wind- that's when you really appreciate lack of vibration and nicely tuned pids!
Oh and lastly, if you use 5.8 tx anywhere on the machine, keep it well away from the gps- it causes big issues. Best to mount well away and pointing down.
Let me know how you go!

Hi Martin,

Please have a look at my circuit. I am using an ESC to supply my servo output rail and it is getting power. But as mentioned before, the signal out from pixhawk is the culprit!And also the RC  calibration figures are around 1100 ....1900. Will it be an issue with the firmware I am using? Or do I need to have a PPM encoder in between? Please help me... I am using Futaba 14sg as my transmitter...I have already checked the servo by directly connecting to the receiver and its working fine....

Thank you


I have the same issue, connect with futaba 6203sb. In qgc, rc signal cal. Normal, everything normal, however, after push safety button and arm stick position, lights ready, the motor no reaction with the throttle. Then i flash back to apm firmware, everything goes alright, can fly immediately. The problem should be the firmware pwm output problem.
Hi madhuraj and eagle,

Sorry for the delay in getting back to you, been making the most of the good flying weather. That setup looks ok. I am using the 14sg and 7008sb too, if you see earlier in the thread I had issues too. The beta testing firmware did allow me to calibrate but I had terrible control issues and the aircraft was unflyable. The solution was to use a ppm encoder and re flash the stable firmware, I have had no issues since then. I would highly recommend doing the same until the beta becomes stable. It will be resolved in time , I'm sure. The ppm encoder is cheap and it has the bonus of extending your mounting positions ;-)
I think if you do this all your problems will be fixed, everything else seems fine. Let me know how you go.

Hi Martin,

As suggested I have already placed an order for the PPM encoder, I think it may take a while for me to get it..I have ordered the one from 3dr stores, hope it will work.. Will update you once I get it

Thanks for your help,


Hello, I just became a new member and have exactly the same problem here. I went from a perfectly well running system (DJI Naza V2) to a lot of frustration. I have Futaba R700SB-14SG combi. I have it connected to the RC port of Pixhawk and tried 2 modes on receiver (A and B) and S.Bus-SBus2 combination. I managed to get connection with the Beta software: V3.3-dev and see some "green bars".
I wonder if I need to purchase a PPM encoder or wait for a working stable version. I see so many developers versions and lost track of a version that is actually suitable for Futaba R7000SB.

Any suggestions?

Right now I would use the ppm encoder and the stable firmware unless you are very experienced. It will all come in time, as each new tx/rx comes on the market it takes more and more work for the volunteer devs to incorporate them into the firmware. The encoder is very inexpensive and easy to use in the meantime.

Best of luck

"Pixhawk is a PPM-input autopilot, which means that it gets RC input from a single cable to the receiver, either via the PPM port, the Futaba S.BUS port, or the special satellite receiver port for Spektrum gear"

"Most modern RC receivers (and all those sold by 3D Robotics) allow for PPM output, but some, such as non-S.BUS Futaba receivers, do not."

So why I need a PPM encoder when on 3DR site I read Pixhawk support S.BUS?

I cant use my Pixhawk (I orderd 1 years ago) and still  wait for S.BUS supported firmware version.

I tried RC versions but I have a near flyaway so wait stable.

I paid 530$ for Pixhawk with shipping, fees and customs. And now I can sell about 150$.

Thanks for your suggestion Martin. I will order one. I haven't figure out yet how I should program the different flight modes and other useful settings. Is there someone with good suggestions?

No probs! All the info you need is here http://copter.ardupilot.com
Click on instructions and it's all there. If you have any problems feel free to ask. There is a lot to read but then this is an amazing flight controller. The wealth of info available via mission planner is simply staggering but don't expect too much too soon as it takes time to get to grips with it (but then that's half the fun!)
I would start with stabilise then loiter and keep it fairly close to you whilst getting used to the controls, be prepared- your first auto mission is like a child leaving home (although you want the aircraft to come back)

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