I have a couple Digi XTend 1W 900MHz modules that I am trying to get working with APM 2.23 and APM Planner 1.0.63.
I have the modules set up for 57600-8-N-1 and they seem to be working fine as a serial link (I can hook them both up to my computer, open a couple terminals, and chat with myself).
I'm also able to enter CLI -> test -> xbee and use the APM as a loopback. I can do the X-CTU range test through the APM as described in the manual here:
However, I'm not able to get a MAVLink connection with APM Planner. MAVLink works fine over the FTDI serial interface. When I try to connect through the XTend modules though, the status popup gets to "Getting Params.. (sysid 1)" and then fails (relevant APM Planner console dump below).
Any ideas as to why the serial link works in general, but not with MAVLink? I'm new to wireless telemetry, so it could be something obvious.
Hope you find a solution. I've got a couple xtends I'd like to use as well.
Well, it works now.
Long story short, my XTend modules came with the RT parameter (GPI1 purpose) set to [1 - BINARY COMMAND INDICATOR]. I set it to [0 - UNUSED] on the GCS module and everything works great. Since the other option is [2 - RTS FLOW CONTROL], I'm guessing that the computer was setting it when ready, putting the module into some mode where it wasn't ready to put data into the Tx buffer.
Next up, range test!
I'll be using this antenna on the ground: http://www.l-com.com/item.aspx?id=25690
Standard duck antenna that came with it on the remote unit.
Of course the transmit power on the ground unit will be dialed down appropriately.
Exact same thing happened to me.
Funny thing is, I actually saw your post *before* I ran into this problem, and specifically checked the GPI1 value to make sure it was set to 0. Did some experimentation with X-CTU, set up to the APM, and ran into the same issue you did. Re-reading params in X-CTU, and found that GPI1 was set to 1 on the GCS module.
It seems that using the X-CTU range test with the RSSI option temporarily sets the GPI1 value to 1 (i.e. binary command; which is also why CTS/RTS need to be connected to get the RSSI output to work in the range test) - if you then inadvertently write this parameter back to the card, or simply don't power cycle the modem before attempting to connect to the GCS after running a range-test, you'll end up getting this error.
How is the range testing going?
I've continued to have a lot of trouble with these units not being able to connect consistently between the APM and the Mission Planner. The one day I took them out to do testing, I couldn't get anything working no matter what I tried.
Another John here also using X-tend modems. I was wondering if you have had any more luck with your modems. I'm also having inconsistent comms with occasional dropots and low telemetry % readings?
Sorry John, I haven't done anything with these since last year. I was actually just borrowing them, and have since returned them. If I ever borrow them again and work with them, I'll post here. There seemed to be some subtle setup or connection issue when I used them -- I couldn't figure out what made them work or not work.
Thanks for the reply mate. I'm in EXACTLY the same boat... I'll keep on searching.... and testing.
I'd refer you to my discussion -> http://diydrones.com/forum/topics/xtend-apm2-gcs-solution-and-more-...
I found a few solutions that you might want to take a look at.