I'm having problems with my XBee Pros intended as the downlink for the Ardupilot. When I hook my Locosys 5hz GPS directly to the computer using the FTDI cable, I'm getting a 5hz update rate as seen in the attached file GPSFDI.txt
As soon as I introduce the XBees in the link, thus GPS--->Xbee (set at 38400) ----> XBee ->FTDI, the rate drops down to on NMEA sentence every few seconds or so as seen in the attached file GPSXbee.txt.

What am I doing wrong? I've separated the two XBees anywhere from a few feet to 10 meters apart, but with the same results. How can I get an acceptable transfer rate with the XBees?



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Try changing the XBee channel at both ends - these radios can be affected by outside interference. In the best case, you should be able to get 80kbps half-duplex transfer rate with these radios.
Thanks Howard. Now the next question: How do you change the channel? In the X-CTU app where I configured the baud rate, PAN ID etc. I don't seem to be able to change the "Operating Channel". Look at the attached picture. When I click on that option/line, I don't get a choice of channels to choose from.

Look at page 26 of the XBee manual . Channels 0x0C - 0x17 should be available. It's been a couple of years since I worked with the XBees, but I think we generally moved up to channels 0x10 - 0x15 when we had interference problems.

However, I just noticed that you're using the XBee in a mode with which I'm not familiar - we never used the PAN addressing. So it appears that the address allocation is controlled by PAN configuration. I suspect you want to be in a non-beacon mode without a coordinator.
That makes sense. Based on the Function Sets available in X-CTU,. which should I choose to set both XBees up in the correct mode? See attached picture. I'm all new to the XBees....


Sorry - I don't recognize any of those modes. Maybe someone else can comment.
If Jordi or Chris reads this I'm curious how they set up their XBees. I'm pretty sure they use the same modules. Also, what update rate do you get?

Anybody else know what is the correct way to set these up?

I'll be interested to see their comments as well. There were two different versions of XBee modules, which were referred to as Series 1 and Series 2, but appear to now be called XBee-PRO 802.15.4 and XBee-PRO DigiMesh. We used the Series 1 hardware, and shipped more than 1000 of those modules with our robots before switching to Wifi radios.

Actually, if I wanted to start again with XBee, I'd be using the new XBee-PRO 868 modules, which are the 900MHz version. I took a quick look in the manual, and it doesn't have any of the PAN addressing stuff.
Bump - Anybody knows how to correctly set these XBee pros (Series2) up?

Are you using xBee PRO series 2?
Yes, those are the ones.

UHH!.. good luck man.... xBee series 2 are very different from series 1, but I can help, i don't have time today, but maybe tomorrow afternoon i can tell you how to do it... Just try this:
One must be end device, the other must be the router, they should have the same PAN number.

Fallow the instructions of this manual..

Now with this manual, the modules will only work in one direction, in order to do it bi-directional you must specify in the router the destination point (With X-CTU), you can obtain the destination of the "End Device" using X-CTU too, . Sorry but i don't remember the names well... I have to find my units and reconnect them to my PC..
Hello i back: Try to program your modules with the configurations indicated in the next pictures:

Ok one must be coordinator and the other router (sorry i didn't remember the names) marked with yellow. The PAN ID must be the same, and the Source/Destination End point try to put the same too (RED)... Now pay special attention in the green arrows, You must define the Destination Address in the Coordinator, you must copy the Serial Number HIGH and LOW bytes to the Destination Address exactly.... In this way you will have bidirectional com.

In the Second Photo you will see where you can change the baud speed, both modules needs to have the same baud...

Took me some time figure out this...

Good luck.

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