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#1 PLMS Feb 25, 2010 10:25 PM

FrSky 2.4ghz - Telemetry protocol discussions
 
2 Attachment(s)
I felt it will pay to branch out now to this thread for talking about the nuts and bolts of the FrSky Two Way systems telemetry protocol, and how to best use it.

The two PDF documents from FrSky are attached.
Martin

The originating thread is here
http://www.rcgroups.com/forums/showthread.php?t=1176328

#2 Iflyj3 Feb 26, 2010 04:11 AM

Thanks for the docs. They do help. Now, I am waiting on the availablilty of the system.

Dan

#3 Julez Feb 26, 2010 04:24 AM

Way to go!

This will be a very cool hack project.

#4 PLMS Feb 26, 2010 05:36 AM

Quote:

Originally Posted by Julez (Post 14451317)
Way to go!

This will be a very cool hack project.

Yep, I think FrSky may be very clever to build the telemetry into their modules AND make the protocol public. I imagine a lot of interesting DIY projects can be sporned from this bit of gear, and of course sell more modules for them.

We should try coordinate effort a bit, but I know everyone will have a different pet project.
KISS (keep it simple stupid) is the way to go initially for me.

My first thought is to build a local-end display using a 16x2 Hitachi LCD and a 18 pin PIC. I like the PIC16F819's at the moment, but could use others if there is a better and easy to get suggestion.

The second thought is then to add buttons and serial commands to program the alarm points in the TX module without a PC.

Then go to the remote end and make an interface for the EagleTree E-logger to 4800b serial, to be sent over the serial link.

Each stage builds on the last.
That's just my quick thoughts, you guys must have many more. Hit the thread with them.

I'll knock up a serial cable tomorrow and have a look at the TX modules output. I suspect I'll need to use something HEX friendly like VBHexterm rather than Hyperterm though.
http://www.synthmodules.com/vbhexterm.htm

#5 renatoa Feb 26, 2010 06:09 AM

Quote:

Originally Posted by Julez (Post 14451317)
Way to go!

This will be a very cool hack project.

Bye, bye, Hitec... you missed a great opportunity to be the first... :(

#6 lazy-b Feb 26, 2010 06:09 AM

Guys,

May I suggest to use a very common microchip such as PIC16F628 and a simple 2x16 LCD as display, so that every RC Modeller can easily purchase the CHIPS and LCD Display...........another even cheaper display is to use a simple 4 Digit 7 Segment LED Display......... hope you can also share its source code.

I guess, the finished products will just look like a simple terminal a 2 x 16 LCD display with 4 Button , this is very common Display terminal used by Mini TURBINE Engine use in RC JET Plane.

#7 Sid3ways Feb 26, 2010 12:19 PM

Subscribing. Someone get Melikh to design some hardware we can buy thats PNP. :)

#8 MelihK Feb 26, 2010 01:02 PM

Quote:

Originally Posted by Sid3ways (Post 14454025)
Subscribing. Someone get Melikh to design some hardware we can buy thats PNP. :)


Hehhee I'm Here :)

Actually i designed new LRS with XBee modules. And it's on production now :D
You can control plane by PC or remote from 45 km with Xbee Pro modules :D
Reveiver module including voltage controls and extra 6 channel analog sensor input to telemetry.

PCBs on production now , i will receive them in 2 weeks :)

#9 PLMS Feb 26, 2010 06:00 PM

Quote:

Originally Posted by lazy-b (Post 14451622)
Guys,

May I suggest to use a very common microchip such as PIC16F628 and a simple 2x16 LCD as display, so that every RC Modeller can easily purchase the CHIPS and LCD Display...........another even cheaper display is to use a simple 4 Digit 7 Segment LED Display......... hope you can also share its source code.

I guess, the finished products will just look like a simple terminal a 2 x 16 LCD display with 4 Button , this is very common Display terminal used by Mini TURBINE Engine use in RC JET Plane.

OK, I have PIC16F628's in my parts box, so I'll use that one.
I'll go with 16x2 LCD myself, they are so cheap now and I have lots I've scrounged from old hardware.
Yes, the source WILL be shared. But keep in mind that I'm a Hardware guy that dabbles in Software, so don't expect too much finesse...

Melihk, whats LRS stand for ?

#10 RobertWing Feb 26, 2010 06:03 PM

hi, Melihk,
I can not believe my eyes. could it range for 45 km?

#11 Sid3ways Feb 26, 2010 06:51 PM

Melihk is my hero and this is just in time. I've been shopping for a telemetry system that would give me a range out warning (Hitec fell short, Jeti Duplex not available in US) and this FrSky system looks to have some potential. But I guess I won't need much of a range out warning if I have a signal 30 miles out. I know the XBee modules are great and many quad flyers use them. It sounds like an all in one solution, let's get it done Melihk. :D :D I'm your 1st customer.

#12 RobertWing Feb 26, 2010 07:57 PM

here is the setting software by FRSky.
http://www.frsky-rc.com/download/fdd...al-version.rar

#13 MelihK Feb 26, 2010 11:14 PM

Quote:

Originally Posted by RobertWing (Post 14456823)
hi, Melihk,
I can not believe my eyes. could it range for 45 km?

Yes this is maximum range of XBees.
I'm planning to sell only RC reveiver and transmitter boards(you dont need that if you want to use PC) and customers will buy XBees from sellers like Sparkfun.
It is best option for everyone because;
- XBees selectable to 433Mhz-868Mhz-2.4Ghz
- Ranges selectable in 30 meter to 45km

@Sid3ways
Thank you very much for this compliments :rolleyes:

#14 PLMS Feb 27, 2010 07:11 PM

A quick play on the bench with serial output.
 
4 Attachment(s)
I have had a busy weekend with little time for FrSky fun. However I have got some HEX dumps of the serial stream from the TX module to post up.

If you don't have a HEX EDITOR to open the LOG files with you will see just rubbish on screen (notepad etc will try display hex in ascii characters).

To see the raw hex output open the log in something like this.
http://wwwwww.mitec.cz/hex.html

If you don't want to do that, then look at the PDF's, but they are not the whole file, just a page.

Frames start with FF FE, there are 10 bytes total. Signal level can be seen varing on the 5th byte of the second log file. I attenuated the signal with a piece of steel pipe over the TX's antenna to vary the level.
00h seems to be the value for strong signal/low errors, the value goes up as errors go up (signal going down).

The 'Range Out' warning beeper in the TX module started beeping, so it was really cutting the signal down. The RX end was also around the other side of my house BTW, my shed door was shut too. The system seems quite sensitive based on testing other brands the same way.

Martin

#15 PLMS Feb 27, 2010 07:36 PM

VB app programmers ?
 
Any VB guy's listening on the thread ?

We could do with a VB Hex term appy that will look for the FF FE header and display the frame in a box, with each new frame over-writing it. This will make setting up sensors etc on the RX easier to do, as it's MUCH easier to see where that byte you're interested in is changing if it's in the same place on screen each frame.

The app could actually have multiple 10 byte boxes down the screen and grab each different header and it's data and display in their own 10 byte box.
Looks like there's 8 possible headers (e.g. FF FE........ FF FA........ etc).

Also good later would be a VB app to send the alarm setting commands...

Can anyone do this, or know of an existing app ?


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