Hi all - I’ll try to keep this as short as possible. A few years ago I decided to build an APM 2/5/2 based quadcopter with GPS and all the goodies. I did it and liked it a lot. Somewhere in time, I was having issues installing the 3DR radio and with my crazy schedule at the fire dept, life got in the way and the quadcopter got shelved. Here we are 3 years later, I am now retired and I decided to get back in the air with the old bird. I connected with the computer (USB) and honestly I lost track exactly happened and in what order but I believe the OSD got new firmware and who knows what else did. My issue at this point is that telemetry no longer appears on my video (minimOSD) nor thru my 3DR radio to the groundstation. I picked up a new OSD the other day but we still have the same issue. I know that APM2.5.2 can only handle firmware V3.2.1 but should it be compatible with newer OSD firmware? I hope this makes sense - I am almost ready to fly but without telemetry I would rather see if I can get it working.I have also tried multiple versions of Mission Planner but still no good. One last hint… When the quadcopter is connected to my PC thru USB, it works great as far as seeing all the data available, just no telemetry to OSD or 3DR radio. Is this a firmware issue??? Am even considering getting a PixHawk and replace the board as a last resort but I spent $90 on the APM a few years ago and would like to salvage it for the time being if possible. Any help would be appreciated. Charlie
Long story short: if you have APM connected to PC through USB - no telemetry stream on TELEM port. That’s feature, not the bug. Disconnect USB, power APM through power module or servo rail and you’ll see OSD and telemetry working (remember - in Mission Planner change data rate to 57k).
Thanks Marcin , but I didn’t explain good enough. I didn’t expect a data stream with USB connected - Only when bird was on it’s own battery power thats the only time the video is alive anyway. With battery connected there is no data from APM to the OSD to the video stream or to the 3DR radio- only ‘Waiting for Mavlink heartbeats Ver 2.2’ on the display. Nothing has changed since the day I shelved the unit into storage except recent firmware upgrades. I replaced the OSD but no good. Got me baffled…
It is very do-able, but the minimOSD can be a pain sometimes with the different versions of firmware for it.
Not all work.
1st thing to do is get your 3DR radio working independent of the OSD.
Minimalise, remove the OSD, and just have the radio.
Go through the Wiki on getting the radio working.
Be aware that different makers have changed some of the pinouts, so check that if the obvious settings aren’t working.
Might be the Tx/Rx are crossed (usual gotcha).
If the green LED on both radios (FC and PC) are solid green then they are connected and you just have to make sure your settings are correct in the PC to connect (Com port and Baud rate).
Follow the Wiki.
Once your radio is talking it is time to link in the OSD.
All it needs is the ‘T’ connection to the Tx line, but be aware that the OSD does not initiate MavLink on the Telem.
You might find that you need to connect the radios before you get a MavLink stream.
If the radios are talking, and your linked into the Tx correctly, connected to the OSD’s Rx, you should see data.
In some cases I have found that I see nothing until I disconnect the camera feed and reconnect, which seems to reset the OSD and it then displays the data.
Only seems to happen with some cameras that are over 600line.
So you may have to try some different (older) FW for the OSD as you haven’t said what versions you have tried.
[quote=“ChiefShu, post:3, topic:23319”]
‘Waiting for Mavlink heartbeats Ver 2.2’[/quote]
May be a clue as it says 2.2, which I am assuming is the Mavlink version.
APM 3.2.1 is MavLink 1.
If it’s the OSD FW version then I have had issues with it as well.
Because you have no OSD nor 3D Radio telemetry - I’d expect that problem is on APM or cabling - not rest of HW.
Please show photos of connections and SR* params.
Well, some progress today thanks to your post and another mystery surfaces. We all like mystery’s right?. I have at least two issues here, telemetry thru the radios to MP and (2) telemetry not included in video signal from OSD. OK, basic troubleshooting. As you said, lets get the radio working and talking to the PC first. I did as you suggested and DC’d the OSD completely from video connector AND the APM/radio side. The radios link up (solid green leds) and the MP still did not connect. I then temporarily went back to USB connection with the bird and looked at the full list of param’s in the APM. AH-HA! The Serial1 baud rate was 110. I changed it to 57, wrote the file to the bird, DC’d the USB and reconnected with radio and it freeking worked. Good telemetry thru the radio to MP. YES - Marconi would be proud!
I will summarize the next 3 hours head-banging…
When the OSD is connected to video and APM, the radio link is broken(green LED flashes) Reboot the birds power and I have good telemetry being transmitted with the video. Sweet. But what happened to the 3DR link? It will not link as long as the OSD is powered. Period. I can have one or the other but telemetry with the video will not work at the same time Radio link is working. Is this normal? Actually not a BIG deal, I can still connect to MP and do stuff , and I can fly with telemetry on the video - just not at the same time…I’m repeating myself. Sorry. Long day
Oh… more details
The OSD firmware IS Ver. 2.2
The only MP that appears to work is 1.3.50 (I tried older versions but NG. Prob a firmware issue?
My battery was worn down from all the fun so I will continue later - prob Friday.
But progress is progress. and I had some today. Thanks for all your help Mike
As the OSD is a passive device on the telemetry port it sounds like cabling.
For the Radio to hang up when the OSD is connected the next question is how are you powering the OSD?
It is best to have only ground and Tx from the telemetry port hooked up to the OSD.
Could you have the Tx from telemetry hooked to Tx on the OSD?
Just asking the obvious questions.
The OSD is powered from both sides - video connector and telemetry side. I will DC the telem side only leaving TX & gnd . . Since the APM & GPS are stacked, I will have to take things apart to verify wiring, Thank Mike …off to the shop