I am new to the XBee world, that is why I thought AT parameters could be a good way to begin with. Unfortunately I am experiencing some problems I can’t understand.
I’ve been given three Xbee Series 2 modules: a Coordinator AT and two Routers AT. I am controlling the Coordinator by means of a PC running X-CTU. The routers are connected to a PIC microcontroler each with which they exchange AT commands. First I succeeded in communicating the coordinator and one of the routers. Then I wanted the third device to join in… and my nightmares began!
The third device would not connect. All the three of them defined a PAN ID 0, but the channel was chosen by means of a scan (SC=1FFE). I noticed the two devices “talking” had CH=12, whereas the one not connecting had CH=13. I never understood this, for the three devices were together on the same table!
I tried to be smarter than the modules and made them scan only one channel (SC=80). Thus, only channel 12h would be scanned and, therefore, chosen. I succeeded in this, but I must have changed something else: nothing worked from that moment on.
I tried to go back to the preliminary value of SC, but it’s not working either. Whenever I check the AT parameters in both modules I see:
AI=0 (which means a network has been created)
AI=0 (which means the device has joined a network)
Moreover, pin 15 of each module is blinking as described in the manual, indicating right performance. However, the data input to the router through the PIC never reach the coordinator and those input to the coordinator never reach the router.
Might I have changed some other parameter(s) and spoil it all? Might I have ruined them? I don’t know. I keep reading the manuals, but I can’t find out what I have done wrong…
At this point, I must confess there are some basics I don’t quite understand. For instance:
- Can a coordinator device be programmed to be a router/end device (or vice versa)?
- How come there are so many options in the pop-up menu of the “Function Set”? Well, it doesn’t matter now. I guess that, in my case, my modules can only be Coordinator AT, Router AT or End Device AT. Am I right?
- How important is the version of the Modem XBee in order to guarantee the communication is successful?
- Are the Xbee Series 2 modules better for a beginner like me, or would you advise me to get the “Series 1” instead?
I’d be very grateful if some of you could find some time to give me some insight on how to solve this out.
Thanks a lot.