My first post in this thread. I just got my 3DR APM2 + Stuff yesterday and trying to sort it all out. I am having difficulty getting the 3DR radios to talk to one another.
S1K 1.5 both radios
Solid green LED on both
Can read stats with MP
BUT cannot get them to talk to each other through the "Connect" button.
I have read this thread with intense interest and see that others got to this point and either resolved and didn't tell how or RMA'd the radio set and the new set worked.
I think I am close but my be missing some subtle point. Appreciate any tips or suggestions.
The "Connect" button is not for connecting the radios. They automatically connect, you can tell they are connected by a solid green light. (instead of flashing)
The connect button is for connecting to the APM. Likely your radios are working just fine.
The radios have made a "hand shake" that is for sure but I am not getting telem from the "air" module. What to do? Neither do I see the red data LEDs flashing.
Connect both radios to your computer. The ground side plugs right in. Hook the air side up to a serial TTL adapter. Open two com port terminals and connect one to each of the radios. What you type in one terminal window should appear in the other.
If this works then the problem is not your radios.
Ok. Did as you suggested and get positive results. So, I guess the radios themselves are operating OK. What else could be causing the lack of Telem from Air to GS? Thanks for any advice. Btw, in the GS Wiki, it says to connect with the Com port of the Ground radio. That's what I was trying to do before. Is there some other way I should be using?
So the radios connect and we know they are communicating fine. The problem must then be in the APM-3DR connection.
Most likely case is that you have either the APM or radio serial speed set wrong. Check both of those. You can also try using a TTL adapter directly to the APM telemetry port to see if it's working right.
The radios are set to the correct speed. How would I check the APM?
Connect to the APM in MP with USB. There's a telemetry rate in the settings.
The setting is... configuration -> standard params -> telemetry baud rate
You have to remember there's 4 speed settings... APM telemetry speed, air/ground radio serial speed, air/ground radio air speed
Ok. Unfortunately, the APM was also correctly set to 57600. Any other ideas? I have two emails into DIYdrones but I guess they are busy.
Do you have a serial TTL adapter? If so then check the APM telemetry output.
Otherwise I'd put it on your list to get one. They're less than $5 on ebay and it's pretty hard to troubleshoot all your serial devices without serial reading capability.
No I don't have a serial TTL adapter. Would you be so kind as to recommend one. This is really getting me down. There was another fellow on this thread who appeared to have exactly the same problem and then he had a Eureka moment. He found the solution and got all working but never shared what he did!
I was am really happy with my other OSD/Autopilots but they don't have telem. Wish 3DR was a bit more responsive too.
You can use an Adafruit FTDI cable. It can be purchased from the 3DR store, Adafruit or other robot hobby websites. It is a good addition to your electronic toolbox.
IIRC this is my adapter I use...
You can also search ebay. "3.3v ttl usb" will probably get you lots of good results. I've had excellent results using 3.3v with 5v systems. So I suggest getting a 3.3v version. They pretty much all have 3.3v and 5v power to go with the 3.3v signaling, so you can interface and power almost anything with one of these cheap adapters.