LibrePilot Forum

General Category => General Discussion => Topic started by: ggrif on December 12, 2015, 01:40:15 am

Title: What bone head thing have I done now?
Post by: ggrif on December 12, 2015, 01:40:15 am
I have a Taranis+ and 4 flight worthy multirotor's, each equipped with D4R II  rx. Each has a specific model set up in the Taranis

I had the three with V9's powered up getting sat locks. Don't ask why.

I turned on the Taranis and noticed ALL the rx's had green LEDs, showing they were bound to a transmitter. Huh?

I pulled the battery on one then just for shits and giggles, armed and very carefully tweaked the throttle, both the others motors started turning 😱. At this point I killed the tx, pulled the plugs and ran for the iPad.

This can't be right, I thought each tx/rx bind was MODEL unique, I mean, it has to be

Or I'm crazy.
Title: Re: What bone head thing have I done now?
Post by: hwh on December 12, 2015, 02:18:28 am
I don't have a Taranus but I'm guessing that the last time each of the receivers was powered up it was bound to the same transmitter.   As far as I know the receiver binds to the radio module in the transmitter, nothing to do with the model in the main transmitter module. The transmitter doesn't actually bind, it just stands there sending to anyone who's listening.  The board in the transmitter that handles the switches, joysticks, and display just sends a data stream to the transmitter module, it doesn't care or control who listens and follows it's intructions.

In normal operation this doesn't matter since you wouldn't usually power-up a second bird without binding it to another transmitter.
Title: Re: What bone head thing have I done now?
Post by: DanNT on December 12, 2015, 02:59:51 am
I found the same thing with my models and from my understanding and limited research the D4R's or any of the 'D' range receivers dont have model matching, its only in the 'X' range - X4R X8R etc.
Title: Re: What bone head thing have I done now?
Post by: ggrif on December 12, 2015, 04:04:24 am
I found the same thing with my models and from my understanding and limited research the D4R's or any of the 'D' range receivers dont have model matching, its only in the 'X' range - X4R X8R etc.

OK, so pretty much a Duh moment for me.

Thanks all, I understand now. I started out with X8R's, thought model matching was across the board.

Always nice to learn something new.
Title: Re: What bone head thing have I done now?
Post by: DanNT on December 12, 2015, 05:32:34 am
Your not alone though. I did exactly the same thing - starting with X8Rs too!
Title: Re: What bone head thing have I done now?
Post by: TheOtherCliff on December 18, 2015, 07:55:43 pm
The basics are that the transmitter has a unique serial number in it.  Each packet of stick positions it sends out has that serial number in it.  There are different data protocols.  That simply means that e.g. D8 protocol only handles 8 channels while D16 handles 16 channels.  The receiver that is bound to that transmitter simply ignores all packets that don't match the protocol it expects and has the unique transmitter serial number it is bound to.

So without enabling something more (that the mfg has designed and built in), if the transmitter has several models that are all set to use the same protocol (e.g. D8) then the receiver will connect to any of the several models.  Likewise several different receivers will all connect to a single transmitter model.  Since you should never use the transmitter trims, I have just one transmitter model that I use for all my quads.