How to use PBR receiver S Bus in a system?

  • I tried to use a PBR-5S receiver with a cheap gyro in an existing foam airplane. The gyro accepts S Bus and I connected the PBR to the gyro and selected S Bus output in my CORE for the Rx output channel 5E and S Bus input mode for the gyro. By using Futaba channel mapping I was able to operate the control surfaces. I was also able to use Channel 3 for throttle directly. But the PBR outputs for channels 1,2,4 still output PWM servo signals for aileron, elevator, and rudder, and with channel 5 taken up by the S Bus cable I couldn't see a way to operate the landing gear. So either that is correct and only 4 channel operations are possible from the PBR-5S when using S Bus -OR- there is some way to use the PBR receiver outputs that I do not know about, fairly likely since I have never used S Bus before. I'll go re read the CORE manual now just in case the answer is there. It's certainly not in the receiver manual.

  • Hello,

    yes- sure if you use output 5 as an S.BUS you only have 4 PWM. As you connect the Main functions to the gyro then, you have 4 channels for motor and landing gear.

  • Hopefully I am doing this "the right way". I changed the PBR-5S receiver output E to S.Bus and Output A Start to CH6 in the CORE. Then I could assign the gear to servo 7 (B2) and throttle to servo 8 (C3). Everything appears to be working normally. Time to fly.

    I do have the rather odd symptom reported by others where the servos occaisionally "jump" a tiny amount. Usually it will sit quietly for a couple of minutes then glitch a couple of times then sit quietly again. It will do this even across my yard and in range test mode. Was the cause for this ever found?

  • Hello,
    Can you explain to me what I have to do to read the "Log" files on my PC by connecting my "Core" with the micro USB cable.
    JC Grateau


    Pouvez-vous m'expliquer ce que je dois faire pour lire les fichiers "Log" sur mon PC en connectant ma " Core" avec le cable micro USB.


    JC Grateau

  • I'll check tomorrow but I believe I upgraded the Rx to V1.6. I posted seperately about my experience with that upgrade process. I suppose I could do it again. The aircraft has 12 flights on it between yesterday and today. It flies fine and the effect is not noticed in flight but the servos still have that occasional small quick jump which I see or hear on the ground. Anyway I see there was something to do with this issue in update V1.5. If I re try the update do you recommend I update from the CORE or the terminal?

  • CORE update went smoothly, showed successful installation of V1.6. System still "jumps" though. I watched it for a while and verified that all servo driven surfaces are jumping together in unison. Aileron, Elevator, and Rudder/Steering are all driven by the 3 axis gyro via S-bus. They all use Y harnesses so all six servos jump. The throttle and gear are driven directly from the PBR-5S. Neither appear to be affected (I ran the motor at low speed and when the servos jumped the rpm did not waver) but I'm not sure the ESC can react that fast.

  • Thanks. I have another "data point" for you. In another Freewing foam EDF I have been flying all this year is a PBR-7S. I installed the same type of inexpensive but very popular gyro today in it. These gyros are not Powerbox quality but for these foam EDF they are acceptable. Anyway first step was to update to V2.7 and then make the installation using Sbus via the PBR-7S Fast Track port.. Again the three axis served via the gyro are "jumping" occaisionally without command. This installation went quickly and smoothly now that I know how to do it. It is really cool how the Sbus system option and ability to change the channel start order in PowerBox receivers expands the capabilities! But yes the "jumping" points to some incompatibility. I will try to PM you the vendor and type of gyro which I am using in these aircraft.

  • Well I don't see how to send you a private message but these are the gyros sold by "Motion RC" here in the US for their extensive line of foam aircraft models, it is the least expensive gyro they sell and it is a 3 axis gyro. As a new user of Sbus I have no experience of the systems reliability or how well various Sbus systems work together. The gyro manual refers to Sbus as a Futaba system.

  • Hello,

    but if the PBR-7S does the same you have to contact this gyro manufacturer. It´s not on our side. Many people are using the S.BUS output for helicopter flybarless systems or other 3rd party devices and all of them work fine the last 2 years.

    Use a iGyroSat on the PBR-7. That´s the smartest solution, no 3rd party incompatibility

  • Following up, I spoke at length with one of the important figures at Motion RC here in the states. He was fascinated with the CORE and Powerbox radio technology and freely offered that the "high end" German system we have here may be over specified for the inexpensive (cheap!) Chinese electronics found in these foam aircraft. Apparently it is just not that unusual to have compatibility issues. At the field yesterday with our local foam EDF expert I learned that the "jumping" I experienced is not unusual and he has also experienced it with these electronics and his Spectrum transmitters, even when not using Sbus.

    I'm not sure an apology is required here but you know I love to dig around and get to the bottom of things! I'll ask any question, not to place blame, but out of honest curiosity.

    Anyone who reads this thread please note that the servo glitching I experienced was in no way due to my PowerBox products. It appears to be caused by the gyro manufacturer (non PB) soft or hardware.