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Topic: Xbee Baud Rate (Read 1 time) previous topic - next topic

caseyzahorik

I'm trying to set the baud rate of the of an Xbee using an Arduino and it seems like it should be an easy task using terminal software or X-CTU. However, I've been unable to connect to the Xbee using the Arduino as the serial device that is connected to the computer to set the baud rate. I'm mostly wondering if it's even possible to do this or if i need additional hardware outside the Arduino and the Xbee Shield from SparkFun to be able to communicate with the Xbee directly so that I can set the baud rate. I'm using an Uno R3 if that helps. I can provide any additional information per request.

Thanks for your assistance!

PaulS

Quote
I'm mostly wondering if it's even possible to do this or if i need additional hardware outside the Arduino and the Xbee Shield from SparkFun to be able to communicate with the Xbee directly so that I can set the baud rate.

Yes, it is possible. No, you don't need more hardware. In fact, you need less hardware. You need to remove the ATMega328 chip from the Arduino while you are doing this. Be sure to keep track of which way it is installed, so you can reinstall it the same way.

That's a hassle, so getting a USB Explorer is a good idea.

oric_dan

Assuming a UNO board [which you didn't specify], you cannot connect XBee to Arduino header
pins 0,1 [Rx,Tx] at the same time as talk to the Arduino from the PC via USB. The signals
conflict.

You can do what Paul says, but you have to cross-wire the XBee to the Rx,Tx pins to get the
USB port thinking the XBee module is an Arduino.

You can also avoid removing the 328 chip by simply holding it in reset - easiest way is to short
the Reset pin on the ICSP header to ground [don't short the Vcc pin by mistake].

caseyzahorik

#3
Dec 08, 2012, 07:41 pm Last Edit: Dec 08, 2012, 08:06 pm by caseyzahorik Reason: 1
Thanks for the reply, Ive tried taking that out already and i still can't get it to work. Is there anything else after that I need to do either on the Arduino, the shield or on the computer to make it know that you are trying to communicate with the Xbee correctly?

I have tried to just put the shield on top of the Arduino and wiring it up like this:
http://i49.tinypic.com/jidq44.jpg  I tried just putting in the image and it looked awful on this elderly forum software.

Edit: Is it maybe that it's still using the Arduino drivers?

retrolefty

#4
Dec 08, 2012, 08:10 pm Last Edit: Dec 08, 2012, 08:13 pm by retrolefty Reason: 1
The way you have Xbee wired to the arduino pins 0 and 1 in that picture, the AVR chip can send and receive to the Xbee board. If you want the Xbee board to talk directly to the PC X-CTU program you need to switch the wires around on pins 0 and 1 and wire a temporary jumped from ground to the reset pin on the arduino. That will let the Xbee 'own' the USB serial link to the PC with no electrical interference from the AVR chip.

But that is effectively what the small switch does (not sure about the hard reset part) on the Xbee board when mounted on a arduino board, it reverses the send and rec signals to allow Xbee to send/rec to the USB serial link instead of send/rec to the AVR chip.

Lefty

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