PPM Encoders

Archive
1

Can somebody please explain the difference between the two PPM encoders that 3DR offers? Also, are there pros and cons?

store.3drobotics.com/products/ppm-encoder

store.3drobotics.com/products/8 … -version-2

My plan is to use the encoder with the Spektrum DX9 / AR8000 + satellite receiver and my Pixhawk.

Thanks in advance,

Mike

2

Hi Mike,

Both uses the ATmega 328 p micro and the same firmware, so basically they are the same but the new includes the cables so you don’t need to solder anything.

3

I ended up doing the same thing. Though I did not try it, I was worried about the range of simply using the AR8000 satellite receiver connected to the spektrum port on the pixhawk. I have the AR8000/Satellite/PPM converter, and it works great.

4

Can someone maybe explain the rather confusing info I’m getting from Spektrum RC and also 3DR:

Pixhawk is a PPM input A/P, check
All Spektrum R/X is PPM says HorizonHobbies…Mmm, check, i guess

How can a receiver be PPM out, and a Pixhawk PPM in, when the latter has one input port on the side, and the first have X amount of PPM outputs???

(I have the PPM encoder just because as described above - need more R/X diversity.)

Maybe there is a way to connect a main Spektrum r/x to the satellite input port on the Pixhawk, to enjoy less cables with preserved multiR/X safety?

5

@Flyhard,
The Spektrum Main Receivers do not have a PPM output. Only the Remote Receiver does. You have to use the Remote Receiver with the Pixhawk.
If you want to use the Spektrum Main Receiver with the Pixhawk, then you will have to purchase and use a PWM to PPM encoder.
Regards,
TCIII GM

6

Thanks for confirming (thus horizon hobbies dont get it :slight_smile:)

7

That said,

To have super redundancy: can you have a binded satellite rx in the spektrum port of the pixhawk and in the same time have the main rx connected via ppm encoder? (That gives both main rx satellites and one satellite straight into the core of the pixhawk, should the main rx connection fail)

8

I don’t think that will work, but if the concern is loosing signal, then you can try the failsafe:
copter.ardupilot.com/wiki/throttle-failsafe/

9

Thanks for your answer! :slight_smile:

Yup, I have failsafe set up when i fly, and it works like a charm when tested, but it is a big and possibly expensive hazzle to abort missions with customers waiting, and loss of hardware is even more a hazzle. (E.g “land” mode straight down a pond or tree or RTL through telephone wires…) Therefore i’d like to know for sure if for example the RC connection on a Pixhawk is prioritized over the Spectrum/DSM port or vice versa or will not work at all.