View Full Version : XBee Test

03-20-2010, 07:29 AM
Is there a way to test the XBee 1 Mw without actually doing the whole setup and programming the stamp such as just using a breadboard with an LED (and pwer) to make sure it works? I have 2 that I traded for and want to test them before I go through the entire setup and find they do not work. Thanks.

Ron Czapala
03-20-2010, 07:51 AM
XBees are 3.3 volt devices while Basic stamps are 5 volts.· You need a way to power the XBee with 3.3 volts and also limit the voltage to any XBee inputs to 3.3v or you will fry them.

That is why Parallax (and others) sell XBee adapter boards to let you interface safely with the transceiver.
The adpater boards·typically contain a 3.3v voltage regulator and a level converter IC to handle the 5v to 3.3v signal lines·(the new Parallax adapter board uses a 74LVC244A chip) see the schematic:


The USB addapter board http://www.parallax.com/Store/Accessories/CommunicationRF/tabid/161/CategoryID/36/List/0/SortField/0/catpageindex/2/Level/a/ProductID/643/Default.aspx
along with the DIGI software X-CTU http://www.digi.com/support/kbase/kbaseresultdetl.jsp?kb=125··is a good place to start.

Post Edited (ronczap) : 3/20/2010 12:57:58 AM GMT

03-20-2010, 08:06 AM
I understand about the power issue. I plan to use that. The question is not about power, I want to be able to test the module without connecting it to my Boe, etc.

03-20-2010, 08:30 AM
What are you trying to connect it to? You could connect it to FTDI 3.3 cables and send data but the xbees still need to be set up before using so you need to connect them to your computer and configure them with X-CTU.

- Stephen

03-20-2010, 07:13 PM
The simplest XBee test, I think, would be to put one XBee into one of the USB adapter boards, and connect to it through XCTU.


Then plug the other into a simple breadboard adapter board


feed it 3.3V, tie RX to TX, and then run the XCTU range test on the one connected to the computer.

You'll have to buy the two adapter boards, and also have a 3.3V power supply. Alternatively, you could put the remote XBee on the 5/3.3V board


and feed it 5V.

Either way you'll need to buy some boards, but if you're going to work with XBees you're going to want some of these anyway. For example, do the XBees you bought have the most recent firmware? If not, you'll probably want to update them, and the easiest way is through that first board. You'll also want to be able to see all of the settings of your XBees, and it's a LOT easier to do that through XCTU than one at a time through a PBasic program.

03-21-2010, 05:53 AM
The XBee's came with the breadboard adapter you mentioned. http://www.parallax.com/Store/Accessories/CommunicationRF/tabid/161/ProductID/642/List/0/Default.aspx?SortField=ProductName,ProductName

Is it possible to just use these instead of having to purchase the USB device?

03-21-2010, 07:52 AM
nwcctv said...
Is it possible to just use these instead of having to purchase the USB device?
Yes, but you need to provide 3.3v power and interface with the tx and rx at 3.3v levels. Make sure you don't overpower the xbee or you can turn it into an xbrick. (x-xbee)

- Stephen

03-29-2010, 08:48 AM
OK, So I guess I will be buying the USB board. My next question is this, if the XBee must have 3.3v, how do I interface it either to my Homework or BOE boards without frying it?

03-29-2010, 08:53 AM
Take a look at the sticky post at the top of the propeller forum. It's an issue with a 3.3v processor and 5v sensors in reverse.

- Stephen

03-29-2010, 09:06 AM
Which one?

Mike Green
03-29-2010, 09:20 AM
Parallax has an xBee adapter specifically for this purpose:

www.parallax.com/StoreSearchResults/tabid/768/txtSearch/xbee/List/0/SortField/4/ProductID/664/Default.aspx (http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/xbee/List/0/SortField/4/ProductID/664/Default.aspx)

This has been mentioned several times.

The "sticky thread" is: Propeller: Getting Started and Key Thread Index
Look under "Technical Considerations:"

Post Edited (Mike Green) : 3/29/2010 2:26:00 AM GMT

03-29-2010, 12:11 PM
Thanks Mike. The "which one" referred to which sticky note.

Ron Czapala
03-29-2010, 11:41 PM
Earlier in the month I notified Parallax that the·LED colors on the original 5v/3.3v XBee adapter board did not correspond to USB version (and the schematic notes).

As a result, they scrapped about 475 boards - the new ones (and the new schematic) now match the USB version.

I also suggested that the next revision use the 74LVC244A to·handle level shifting on the Sleep Request pin.
They passed that along to engineering...

Post Edited (ronczap) : 3/30/2010 11:43:05 AM GMT