Can't connect with telemetry

Hello all,
I received my 3DR Y6 kit about two weeks ago, along with the 3DR telemetry kit. I put together the copter, and have flown it a few times, but haven’t been able to get telemetry to work. I’ve tried searching for solutions, but nothing I have found has worked. I always get a ‘Timeout- No Heartbeat packets received’ error.

These are the things I have tried.

  • I can connect with USB, and it works fine. I can change settings, etc etc.
  • When I try to connect via radio, I am selecting the correct com port and baud rate (57).
  • I have solid green lights on both radios, and when it is trying to connect, the red led blinks on both.
  • I can see both the local and remote radios in MP’s 3DR Radio menu or the standalone 3DR Radio config tool, and settings are the same on both.
  • I’ve tried turning off ECC and/or Op Resend.
  • Uploaded firmware to both radios.
  • Reset to defaults on both.
  • I’ve tried different baud rates, (115200 and 38400).
  • Tried switching radios
  • Tried different USB ports
  • Tried different computers (MP works over USB on both)
  • Connected both radios to the same computer, opened terminal windows with both com ports and can see text sent to each radio.

I can’t recall anything else that I’ve tried. It just seems to me that the radios are working, but the APM isn’t talking to the radio. I’m not sure what else to do.

Otherwise it flies well (crashed it the second flight- pilot error- fixed now), but I still need to tune it - waiting for a calm day. I stuck a GoPro to it for the third flight and recorded some video. It was just after sunset, and looks awesome! :smiley: I was surprised that it turned out so well with no vibration isolation or anything. Eventually I’ll get a gimbal and FPV setup as well.

Sounds like you have done some good troubleshooting

Connected both radios to the same computer, opened terminal windows with both com ports and can see text sent to each radio.

You have the link working.

You have to disconnect the USB cable and power to the APM to have the serial mux switch to use the radio. You don’t mention if you did this.

I’m pretty sure I have done that, but I’ll check again tonight when I get home. Is there a pinout for the 5 to 6 pin cable to the APM? Could the RX/TX lines need to be switched? (something I could look at…)

I have used the 5 pin to 6 pin cable with the new V2 telemetry radio with an APM2.6 and it worked fine for me. It could be that yours is mis-wired, but I doubt it.
TCIII ArduRover2 Developer

Hi Tazikel, have you been able to find a solution? I have the same problem as you, with the same functionality working and not working. I tried the same troubleshooting steps. Still no luck. I also tried switching the Tx/Rx lines but it didn’t solve it.

Something to add to my previous post:
I tried two different PCs and an Android tablet, all have a problem when trying to connect telemetry. However, on my Android phone it does connect but doesn’t show live telemetry data on the android app. On my video feed, I see the Mavlink OSD shows data for a few seconds, then it goes away and only shows “no mav data!”. When I disconnect and reconnect, I get the same thing, Mavlink OSD shows data for a few seconds then mav link drops.
I have the Rx line on the Mavlink OSD connected, but not the Tx line, as per instructions.