APM 2.5 connection to DragonLink v2.81 RSSI & killing boards

Archive
1

Hi All,

I have been trying to get RSSI working between an APM 2.5 and a LR DragonLink 2.81.

Result - Killed 2 APM boards…
Killed - Well, they now only work when I put run power to the input and output rails of the APM.
I’m not sure they can be trusted anymore - Thoughts?

So - What did I do, and can any one tell me why it has happened.

Here is what I did…
In Mission planner, You can choose a few options for RSSI_PIN (-1 is off, 0 is A0, and something else is A13 etc).
I set the RSSI_PIN to A0 (and wrote parm) and then plugged the RSSI pins from the Dragon Link to the APM A0 port and it made no difference with TX on or off to the RSSI value in MP data.
So I changed it to A13 to try a different pin (and wrote parm). Plugged the RSSI feed from the dragon link to A13, and pop, apm goes lights out and nothing.
Thinking I may have done some polarity reversal, I then tried a second board. A0, did nothing, and then moved to a13, and lights out again and nothing.
I think it has blown the surface fuse…?

2 boards dead… :blush:

So - Dragon link says RSSI voltage is analog - 0.75v for 0% and 3.5v for 100%, so well within the 5v for APM inputs.
Why did A13 kill my board and A0 do nothing with the RSSI?

I can only see RSSI_PIN parm in MP - I can’t see RSSI_RANGE parm, but I can’t see this being an issue…

Any help would be great, but my main questions are as below:

  • Has anyone connected an APM and DRAGONLINK for RSSI?
    ++++ If So - HOW?
    ++++ For ArduCopter or Plane? I do need BOTH…!
  • Can I still use the boards safely if I power both the input and output rails (Say a Servo Cable from one rail to the other (pos and neg wires only)?
  • If I do get it working will it show up in MP and will it show up on my Android Tablet via telemetry connection?

HELP…!!!

Thanks everyone - I am getting so close…!

Cheers

2

in your second image if thats the way you wired it then its wrong…

on APM gnd is outside edge and signal is on the inside pin of the board.

on dragonlink the pic of its signal and gnd is correct

3

Thanks - Yes, my diagram is wrong. I had the Neg on the edge (as per the APM side of my diagram) and the DL the opposite to the way I have drawn it.

So I had neg to neg and RSSI pin on DL to Signal pin on APM…

Still after info if anyone can help.

With the amount these are used (APM’s and DL units) - Someone must be doing this already - Surely…

Cheers

4

[mf]Copter/3.2[/mf]
I don’t see any relation to the software in this post, let alone to 3.2. Why did you post that to the 3.2 forum?

Sent from my Ainol Novo 7 Fire using Tapatalk

5

Thanks Stefan - Sorry. Thanks for moving it.

6

It looks like you had it wired backwards.
Please refer to
copter.ardupilot.com/wiki/common … ndication/

7

Hi - There has been some confusion regarding my connection diagram.

I have attached a modified diagram (v2) as I had drawn the wires around incorrectly.
I had it wired correctly, and all my questions still stand - and it seems no one was done this? I find it hard to understand…?

2 well known items, and no one has done it? Really?

Any help would be great, but my main questions are as below:

  • Has anyone connected an APM and DRAGONLINK for RSSI?
    ++++ If So - HOW?
    ++++ For ArduCopter or Plane? I do need BOTH…!
  • Can I still use the boards safely if I power both the input and output rails (Say a Servo Cable from one rail to the other (pos and neg wires only)?
  • If I do get it working will it show up in MP and will it show up on my Android Tablet via telemetry connection?

Thanks

8

if you are flying a quad I wouldn’t bother with RSSI on dragonlink, do a good range check. The dragonlink will have range beyond the flight range of your quad

9

Thanks - No its a large Octo (1400mm prop tip to tip) with 16,000mAH.
Also a Nikon D800, so about 6-7k in $$ all up floating about.

Want it to be as SAFE as possible… :laughing:

Cheers

10

The 2 pins next to the USB port are SPI not A0, the pin next to 3DR-Radio port is the A0.

A13 in APM is power management connector voltage pin
copter.ardupilot.com/wiki/common … input_pins

I would recommend you to add the RSSI filter shown in the documentation:
copter.ardupilot.com/wiki/common … SSI_Filter