APM MavLink to FrSky X8R S.Port converter

Hugues February 11, 2014 at 11:16pm

This is great stuff. Thank you.

I will be ordering a teensy and will connect it on the telemetry2 port of Pixhawk (telemetry1 port in use for 3DR radio and MinmOSD)

Tracy DeWitt February 11, 2014 at 5:20pm

FYI Make sure you have the units on your taranis set to metric. Had mine on imperial and got a lot of crazy readings. Working great! Thanks again Rolf.

Artem February 11, 2014 at 2:01pm

Rolf, another working unit!

Thank you, and if have time, please integrate flight mode info in the prog!

Thank you again!

p.s. is there any progress on teensy onboard s.bus to ppm conversion, it would be really cool, less wires, less mess less points of failure!

p.p.s. there is this project: http://www.wedontneednasa.com/2014/01/using-audio-channel-for-air-t...

and since we already have teensy on board we could theoretically do something similar but much simpler, those FSK modems are 2400 baud and we receive mavlink at much higher rate. so we just need to extract GPS info with Alt and send it to the FSK modem at 2400baud. on the ground we could use this guy's code on another teensy to run a tracker.

Using audio channel for air to ground telemetry

DIY blog around unmanned vehicle, robotics, & other nerdos phantasm.

Rolf Blomgren > Artem February 11, 2014 at 3:17pm

Hi Artem,

I'm working on the S.Bus to PPM converter but I have to be sure that the ppm output is not hanging up, cause then all will blame me for craching. ;-))

I'm also rewriting the code for the MavLink to S.Port.

Regarding the FSK modem i will be back....

/Rolf
- Developer
  
  Andy Little > Rolf Blomgren August 12, 2014 at 5:50am
  
  This project looks great. I have done similar for my antenna tracker some time ago, though I used a Arduino Pro Mini for sending the data rather than a Tiny. The protocol looks very similar, except I only used an 8 bit ID.
  
  Mavlink to FrSky source on Github
  
  Regarding FSK, I have been doing it previously with external modem ic's, but recently managed to get a software only modem working...
  
  Diy antenna FSK info on Diydrones
  
  It would definitely be possible to use the same technique to do the demodulation on an 8 bit AVR if you added an external filter rather than a digital one.
  
  regards
  
  Andy
  
  kwikius/mavlink_to_frsky
  
  Arduino application using Arduino mini/micro/nano to tap Mavlink protocol from Arduplane and send it out to FrSky RC telemetry receiver for my quantr…
- Paul Phillips > Rolf Blomgren February 12, 2014 at 3:00pm
  
  Hmm, it's a nice idea but I think I'll stick with my FrSky PPM convertor for the control side - http://www.frsky-rc.com/product/pro.php?pro_id=112
- Artem > Rolf Blomgren February 11, 2014 at 4:38pm
  
  btw, I found some 4800 baud FFSK modems which should work too, looking at the video of the tracker in action you can clearly see the tracker delay to react when the copter moves fast and close, even though I think a lot of this delay comes from actually converting mavlink into the LTM (they guy's own creation). if we pick GPS/alt data only and skip the rest it should be much faster, but it would be a good idea to pump all the data necessary to run minim OSD on the ground, so in the event of video loss we would still have the horizon, alt and home direction info. OSD on the ground opens up a lot of possibilities!

Paul Phillips February 11, 2014 at 4:48am

This is awesome, great work.

I've just ordered a Teensy 3.1, can't wait to try it.

John Hutchison February 9, 2014 at 6:44pm

Rolf, I am wondering if this is supposed to be functional with the FLD-02. I still get both RSSI, and the A1 voltage as without the Teensy plugged in, but I also get the altitude now too. Every other value is 0. The LED on my Teensy goes solid after APM is powered. I have a DHT-U DIY hack module installed in a Futaba T7CHP with FLD-02, and a Bluetooth TTL-RS232 installed in my Tx. On my cellphone I get the voltage and both RSSI, but selecting hub channels shows no valid data (everything is -1). Confirmed 3D gps fix in mission planner, and good MavLink data.

FYI, moving the APM up/down changes the altitude. I have tried both your original sketch, and also modified as I thought there were some errors in your example for HDOP after I got compile errors.

uint16_t ap_HDOP = 0;

and

case 19:
FrSkySPort_SendPackage(DATA_FRAME,FR_ID_FUEL,ap_HDOP);
break;

APM 2.6 @ 2.78b

Futaba T7CHP w/DHT-U, FLD-02

X8R

Mike Machado > John Hutchison February 10, 2014 at 9:17pm

Rolf,

Awesome work on this!

I am on the Trannis wait list, hope to have it soon. I am converting my fleet over to the X series receivers along with the trannis upgrade. I already have telemetry from my copter over the old "hub" protocol and was looking to modernize with s.bus and found this awesome thread.

I am the guy working on the "mavboard" project (original post here: http://diydrones.com/profiles/blogs/sneak-peak-at-mavboard-progress). I am finally getting around to actually doing a production run and putting a bunch up for sale on indegogo in the next couple weeks. I would love to offer your software on it as well, so it supports both the old and new telemetry modes of the FrSky system. I was wondering if you wanted to work together to get a version of your code working on my mavboard hardware? I can send you some free boards. Should be a simple port (Im assuming just mapping the s.bus tx pin to be the same pin wired to my FrSky connector).

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APM MavLink to FrSky X8R S.Port converter

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