Until now, the only way to connect APM or Pixhawk via wireless is using radio modem. Well, you can also use blue tooth but the range is very limited. It may be good for set up or so but certainly not flying if you wish to view live data. 

For long range FPV or aerial mapping mission, I use RFD 900 radio modem. It has served me well and depends on local environment, I can receive live data up to about 10 KM. It is sufficient for our job most of the time. 

The Dragon link V3 advanced system was released early this year. Beside the usual long range ( they claim up to 50 KM ) radio control, their receiver is equip with bi direction data transfer capability. Once set up, it can virtually replace the long range radio modem. Another added benefit is their transmitter has build in blue tooth so we can use our note book computer to connect with GCS such as Mission Planner or using hand phone / tablet with Tower. This is a full bidirectional connection, so we can view live data AND also upload command or flight plan. 

The bi directional data transfer feature is fantastic to me but unfortunately the earlier version of their firmware didn't help much to get thing set up. Some user had successful link it up with computer or tablet but the blue tooth connection is not reliable. I have tried earlier but no luck. 

Early this month they release a new updated firmware with lots of improvement especially the data modem feature. A user call Noircogi kind enough to post a detail set up guild in RC Groups, which is also found in Dragon Link support page. I follow each step but still can not get it connect to my computer or tablet. After a few post in RC Groups, Noircogi and other help me with some suggestion and point out some error in my set up and now I can get reliable connection. There is actually nothing wrong with Noircogi instruction, just that I misunderstand some points. Therefore I think it may be good if I can put up a graphical guild for those who wish to try.

The work flow of the set up is :

  • Connect the transmitter with computer / tablet / hand phone blue tooth
  • Connect Pixhawk telem 2 port to receiver
  • Configure Dragon Link receiver
  • Configure Dragon Link transmitter 
  • Configure Pixhawk parameter
  • Configure Mission planner parameter. 

Now, lets get start

Connect the transmitter with computer / tablet / hand phone blue tooth

 ( All italic text is copy from DL support, for which I believe is contributed by Noircogi. )  

STEP 1:    Pair Bluetooth to your adroid phone or tablet.  ( Apple NOT supported ). 
Turn your Dragon Link advanced Transmitter and wait about 30 seconds.   Go to the Bluetooth setup in your Adroid Device, and SCAN FOR NEW SYSTEMS.  The Dragon Link will first show up as a number, and then turn into " SERIAL PORT DEVICE " in about 30 seconds.   
Select the SERIAL PORT DEVICE from the list, and choose PAIR.   You will be asked for a code, enter " 0000 " for the code, and choose OK.   The device will now pair, and automatically pair whenever it sees the Dragon Link transmitter, so this only needs to be done once.   Bluetooth has a range of about 20 feet ( 7 Meters ), so your Phone or Tablet must be close to your Dragon Link Transmitter to receive its data. ( Do not confuse with plane distance, the plane or copter can be many miles away ! ).
This step is easy, once you have pair the device, go to next step.
Connect Pixhawk telem 2 port to receiver
You need to build a special cable here. using a 6 position cable, remove wire no 1, 4, and 5, cut off one end and crimped joint with female servo pin. The red wire is in pin 1 originally, I use it as pin 2 wire for visual effect.
Configure Dragon Link receiver
On the Dragonlink Receiver GUI
Select 19200 baud for the radio modem.
Configure the pin you connected to the TX wire from the Pixhawk as "Serial In"
Configure the pin you connected to the RX wire from the Pixhawk as "Serial Out"
Don't forget to "save" and then "reboot" the RX on the main page of the RX GUI.


I set CH 5 as " Serial OUT " and " CH 6 as " Serial IN " You can set to other CH. In the PPM Channel, select 12. This step is not mention in the instruction and I was told it has to be the same number of channel in the transmitter, which we are going to set as 12 CH later. I am not using TX / RX with reference to pin number. This is because I found contradict info which confuse me. TX and RX can be either no 2 or 3. I'm sure those technical guy can easily know which is which by I rather just use number. No 1 is the outer most pin and progressively go toward the centre of the flight controller where no 6 is the inner most.

Save the setting and reboot.

Configure Dragon Link transmitter

On the Dragonlink Transmitter GUI
Main page under RF select; 12 Channels, High Bidir Bandwidth, Fastest Update-Rate
'Radio modem & Telemetry" page select; Bluetooth: Radio Modem, Baudrate: 57600
Save and reboot here too.

Re-bind your Dragonlink receiver to the new TX settings.



You'll need to rebind to transmitter with the receiver again to let the new setting come into effect. 

Configure Pixhawk parameter.

You can configure those parameter by using USB cable plug into Pixhawk or use the normal telemetry. Once connected with Mission Planner, go to Config / Tuning then Full Parameter list and change the value as listed below. 

BRD_SER2_RTSCTS        0
SERIAL2_BAUD              19
SR2_EXT_STAT                1
SR2_EXTRA1                    5
SR2_EXTRA2                    5
SR2_EXTRA3                    1
SR2_PARAMS                   8
SR2_POSITION                 2
SR2_RAW_CTRL               1
SR2_RAW_SENS              1
SR2_RC_CHAN                 0


Configure Mission Planner

Under the same tab, go to Planner and set the following :

Attitude to           5

Position to          2

Mode/Status to   1

RC to                 0

Sensor to           1

Now the moment of truth, Ensure your computer had pair with the transmitter with blue tooth, you can check in blue tooth setting. My Tough Book still running Win7 Pro so it looks like this :

For me. the computer had assigned COM 40 as the blue tooth COM port. So in Mission Planner, select the appropriate port and select 57600 baud rate and hit CONNECT. It should be connect within a few seconds. Now you had full data link. Shall we throw away our traditional telemetry ? No, I don't think so. first and foremost the DL system need more 

time to test for stability more user friendly in term of set up. For serious FPV fun or aerial mapping work where expensive equipment on board, a back up system is never a bad idea. 

Now you can test it out

Power cycle everything. Make sure your PC's bluetooth is paired to your the DL transmitter (for now, you can only do that with the DL receiver powered off).

Launch mission planner.
In the upper-right corner, select the first bluetooth serial port which shows up. Select 57600 baud.
Power on your plane.
Power on your DLA transmitter.
As soon as you see the blue telemetry light show up on the TX, hit "Connect" in mission planner.

It should come right up and work. If it fails right away, select the other bluetooth serial port, power cycle the DL TX and hit connect as soon as you see the blue light.

The settings above give you 5HZ updates on the artificial horizon, 2Hz updates for GPS and 8 parameter downloads per second. At first I had everything much slower but with these settings it's nearly as fast as I was getting with the separate 3DR telemetry radio!

Dropped telemetry packets don't seem to cause any trouble at all.

Noircogi has a nice video which show the full telemetry function using Dragon Link. Data update rate is not much difference, If any, compare to conventional 915 / 433 Sik radio modem.

I think Dragon Link Advanced system may worth consider. Just look at the price of a of pair RFD 900. User had reported
about 10 KM data range for which the out put power of the micro receiver only 25 mW. The soon to be available full size
receiver with up to 1 W out put power should give us a lot more range.


E-mail me when people leave their comments –

You need to be a member of diydrones to add comments!

Join diydrones


  • You can connect the DragonLink through USB, instead of Bluetooth? Thanks.

  • Just thought I would save some others future trouble.  DO NOT try and send serial mav data at above the 19200 that is suggested in this post.  The 57600 bluetooth serial is fine between the transmitter and the ground station, but in Mission Planner you need to set your mavlink serial out baud rate to 19200, not the usual default of 57600.  And like suggested in this post, you need to setup the Dragonlink receiver to receive at 19200.  If you go above this baud rate you will get extremely intermittent telemetry connection due to errors between the Dragonlink Rx and your Autopilot.  Enjoy!

  • Dragonlink just support read only for telemetry.

    In other words, Mission planner can not send any message or requests via Dragonlink.

    So MP can not get parameters via get command, and can not upload waypoints too.

  • I used the GUI and changed the DL Tx bluetooth modes (in the Radio modem & Telem tab) a few times and it worked again.

  • Thien Nguyen,

    did you solve it?

  • Hi Thien,

    I had the same problems. Tried 'everything' with MP 1.3.43 and nothing worked, finally tried APM Planner v2.0.24 and it worked immediately, did a reboot on Windows 10 laptop and power cycle on RX and TX and tried again with MP and it worked, I don't know why.

  • Hi all.

    I have followed the guide, but got stuck at the "Getting Params 1" panel (pic below).

    I see that the connection has been established and telemetry data IS getting through: all data on the Flight data tab is getting updated in real time. The thing is, MP cannot get past the "Getting Params 1" no matter how long I wait (30 mins).

    I have latest firmware installed, try reset to factory settings, use preset settings etc. but no solution yet.

    Anyone has the same problem as mine or any ideas? 


  • Has anyone done range testing with this system USING the telemetry?  Did telemetry feed have dropouts before the RC Link?  I remember reading a couple bits on the Dragonlink site that telemetry range might be less than the RC range.  I'm using this data to point a video antenna and thus would not be very happy if I was flying and suddenly my antenna stopped pointing at only 5km :).

  • Paul, I had a similar problem. Couldn´t make it work with my notebook (an old notebook). I tried then with Tower app on my Android phone and it worked well, so the DL Bluethoot was OK, it was a problem with the notebook bluetooth.

    Now I have a windows tablet and the telemetry is doing well using mission planner.


  • Mine arrived today, spent 9hrs trying to get telemetry to work, no dice.

    Tried 3 different pixhawks at different baud rates, both dragonlink mavlink and radio modem modes, checked with my rfd900 at same settings and works fine.

    Followed this guide exactly and nothing, only time i got any response was in dragonlink mavlink mode via bluetooth but parameters would not download and got a weird voltage reading -40v .

This reply was deleted.