XBee mount

Hi everyone. I've bought 2 arduino modules: http://www.sparkfun.com/products/8664 The XBee explorer dongle http://www.sparkfun.com/products/9819 and the arduino board. I was almost sure this stuff is enough to make my PC talk to arduino with XBee on it wirelessly. But now, it seems to me that I've missed something and I have no idea how to actually connect the XBee module and the Arduino board... Looks like it's completely obvious to everyone, but I only managed to find this schematic: http://www.flickr.com/photos/cairn/2316614579/ However, this is not a connection to the arduino board, but to some other "breakout board" (what on earth is it needed for??). Can anyone explain in details how XBee module is normally connected to the Arduino board and if there is any possibility to connect it in my case without buying extra boards.. (I'm living to far to pay for every shipping :( ) Thanks a lot for the reply.

Well the issues is that XBee modules are 3.3V and arduino boards are (normally) 5V.

People would often go for this: http://www.sparkfun.com/products/9132 or an XBee shield (more expensive).

You can build a level shifting circuit yourself (a few dollars of components if you can get them locally), I found that the adafruit XBee breakout board schematic was a good place to start.

Mowcius

Wait, there is a 3.3V pin on the Arduino.. Why can't I connect the VCC pin on XBee module to the 3.3V on Arduino?

Ixanezis: Wait, there is a 3.3V pin on the Arduino.. Why can't I connect the VCC pin on XBee module to the 3.3V on Arduino?

Well there is but it can't supply enough current for the XBee modules.

You also have to shift the signal levels. You shouldn't send 5V signals into the XBee from the arduino, you should shift the voltage of the signal down to 3.3V

it can't supply enough current for the XBee modules

And why will it be enough using the XBee Explorer? The power is taken from the Arduino anyway..

You also have to shift the signal levels

Could you please explain what signals are you talking about (I'm not very deep into electronics) or point some direction to learn it?

I've also found this post: http://answers.oreilly.com/topic/2458-how-to-connect-an-arduino-to-an-xbee-radio/ This guy has connected XBee just as I wanted to.. Using just a breadboard to avoid soldeing. But after your words I don't believe it will work. Or I have missed something once again?

Ixanezis:

it can’t supply enough current for the XBee modules

And why will it be enough using the XBee Explorer? The power is taken from the Arduino anyway…

You also have to shift the signal levels

Could you please explain what signals are you talking about (I’m not very deep into electronics) or point some direction to learn it?

I’ve also found this post: http://answers.oreilly.com/topic/2458-how-to-connect-an-arduino-to-an-xbee-radio/
This guy has connected XBee just as I wanted to… Using just a breadboard to avoid soldeing. But after your words I don’t believe it will work. Or I have missed something once again?

The power is taken from the 5V on board and then regulated to 3.3V rather than taking 3.3V directly from the FTDI chip (or the onboard regulator).
On the new arduino boards with a 3.3V regulator on board you could probably get away with powering it from that.

That link you posted is slightly flawed. The 3.3V signals to from the XBee do not need to have anything done to them as they are 3.3V high (higher than the required 2.5V for the arduino board) but the signals from the arduino are 5V high which could damage your XBee module.
The modules are 5V tolerant (which means they can take 5V signals in) but it is not recommended as it can damage your modules. The other issue is that an arduino low pulse could be up to 2.5V which could still register as a high pulse on the XBee as 2.5V > 3.3V/2.

Re. shifting levels, the levels from the arduino are 5V (a high/on pulse is 5V and a low pulse is <2.5V), you should shift them to 3.3V (a high/on pulse is 3.3V and a low pulse is <1.65V (3.3/2))

Mowcius

OK then :slight_smile:
Thank you very much for you help, I’ll order the XBee explorer and hope that will be enough to connect everything :).

I recently bought the 2-pack X-Bee-Pro, and shields (Marketed by Liquidware, made by Libelium. http://www.liquidware.com/shop/show/XBS/Arduino+XBee+Shield) and I'm beginning to think it was a mistake, because of the shield design. It only has access to the analog pins, Digital 0 through 7, and the ICSP pins of the arduino, or a Mega, and doesn't allow any shields (especially the protoshields for either the base Arduino or the Mega.) To say nothing of covering over the voltage pins.. Also, the X-CTU software, doesn't support 64-Bit OS's (well, there goes using Windows-7 on an Core-i3)..

I was really hoping to link the Mega on a Tank-Bot design, and communicate to it via PC (which looks like I'll need a different carrier board & the FTDI USB cable.) But, it doesn't look like I'll be able to even connect it back to the Duemilinove on the PC..

Also, the X-CTU software, doesn't support 64-Bit OS's

X-CTU works fine on my Win7 64 bit laptop.

I'm beginning to think it was a mistake, because of the shield design.

It's not a "plays well with others" design, that is for sure. When installed, though, there is a small gap between the shield and the headers below it, so you can stick wires in those holes before installing the shield. It does not allow other shields to stack on top of it, but that really isn't unreasonable considering the need to keep the antenna on the XBee exposed.

PaulS:

Also, the X-CTU software, doesn't support 64-Bit OS's

X-CTU works fine on my Win7 64 bit laptop.

This is what I get, for believing what I read. :roll_eyes:

I'm beginning to think it was a mistake, because of the shield design.

It's not a "plays well with others" design, that is for sure. When installed, though, there is a small gap between the shield and the headers below it, so you can stick wires in those holes before installing the shield. It does not allow other shields to stack on top of it, but that really isn't unreasonable considering the need to keep the antenna on the XBee exposed.

True, But the connection to the ICSP pins really messes things up, especially when not all shields carry the pins through. (the Adafruit Protoshield, for example. http://www.adafruit.com/index.php?main_page=product_info&cPath=17_21&products_id=51)

Hopefully, Solving the problem.. Just ordered the USB adapter (http://www.adafruit.com/index.php?main_page=product_info&cPath=29&products_id=247) and the standard adapter (http://www.adafruit.com/index.php?main_page=product_info&cPath=29&products_id=126) to mount on a Breadboard I'm using as a 'medium' between the Arduino and the various components of the robot. (since majority of the components are signal/pwr/GND connections.) Drawback, is having the two Libelium shields I can't use. :disappointed_relieved: