Servers by jDrones

Last step from rfd900 modem + PPM to the GCS via Bluetooth rather than via USB cable

(karla) #1

Sorry if I posted this out of place, I researched wiki and forums but still cant find answer to my question.

  • Is it possible to make the last connection from a rfd900 modem that uses PPM passthrough to the GCS via a Bluetooth device, rather than via a USB cable?
    The usb cable works beautifully - however its a cable and it limits my freedom of moving around at ground position. I can put a very long cable from my RC transmitter to the rfd900 unit - but it seems much wiser idea to do it wirelessly (via BT).

I can not be the first person here?
My question, can it be done? If cant - then perfectly happy to find other radio solutions :slight_smile:


(Kg Fairbarn) #2

You could use a Bluetooth serial adapter. I’ve used these to test serial connections but have never used one for for any extended amount of time.

IOGEAR Bluetooth Serial Adapter, GBC232A

1 Like
(Matthew ) #3

Take a look at this here.

1 Like
(karla) #4

Thank you both for the replies.
Yes, I read both those post with delight some time back.
I have it set up according to your illustration (less the Frsky, I have another radio).
But from your post I was not sure if you really succeeded or not, since you asked about adding a USB cable connection as well. Anyway got confused there.
Now, very pleased to understand you got it to work!

For me, it still do not work. MP on Win10 machine fail to connect via the HC06 BT unit.
However, I studied the wiki one more time, and think I missed to uncheck the ‘Reset APM on USB connect’ box, and also to check the SPP com port box is checked and that the com port properties for the BT unit has correct speed.
I will check that tomorrow.

For your USB question, Why not power the RFD unit from pin 4 instead of pin 5 and then you solder on cable connectors from a USB cable?
Only TX and RX pins will have two wires connected, should work.

(karla) #5

I am sure now I have done all, according to the wiki after more than triple checking.

But still something prevents the MP to connect via BT HC06 device to the ground based RFD900 unit and onwards to the remote rfd900 and the flight controller.
I have tried three different BT units and all pairs fine and parameters set fine.

Since you got it to work its just a matter of finding the issue.
I see from your picture you have a RFD 900x and I have a RFD 900+ unit.
are they different in this respect? needs other SW settings or cant do it at all?
What do you think?

The BT unit seems to connect, steady red LED and then goes blinking again and finally the connection times out.


(karla) #6

Success :grinning:
Finally got it to work, thanks to Moreton at support at RFDesign.
It was a faulty Bluetooth unit, tricky since it seemed to work but something was wrong with it.
Now all works as expected, its great!

If anyone do not want to fiddle around to set this up, they have a new product that do pretty much the same thing