Receiving Random Data

I’ve never done any work with RF modules before and I’ve encountered some problems. I’m using an XBee Pro and when I tried to test it out with X-CTU, it didn’t go nearly as smooth as I expected. When I press the Test/Query button I can usually connect to the modem just fine. I get:

Communication with modem…OK
Modem Type = XBP24
Modem firmware version = 10E6

Then when I go to the terminal tab, one of two things go wrong. In the much more common scenario, the screen just fills up with random red characters. In the second scenario, after I push a key for transmission, I get fair amount of random characters before it stops and waits for another input. Any ideas on how I can fix this problem?

Is this a new XBee (ie with default configuration) or could it have been configured already? I ask because of the possibility that it’s been configured to send regular data transmissions of input line states.

The easiest thing to do would be to reflash the chip, taking the opportunity to upgrade to version 10e8 while you’re at it. That gets you to a known state.

Oh, and another thought: presumably you have more than one XBee? Do you see the same behaviour on different chips?

If none of this helps, perhaps you could also tell us which development board you’re using, or post the circuit diagram if you’re not using a dev board.

Both XBee that I’m using produce the same results, regardless of which development board they are on. One board is the USB adapter board and the other one is the 5 V/3.3 V converter board. The transmitting XBee has a green, yellow, blue, and blinking red LED on. The receiving XBee has a red, yellow, blue, and blinking green LED on, as well as a red LED that turns on when I try to transmit data.

Ok, let’s see the configuration then. You can use X-CTU to save the configuration as a .PRO file. If you do that for one (or better, both) XBees, and post the files, that may give more of a clue as to what’s going on.