Team Building Gets The Hardware

I got a lovely surprise today. The hardware for our Micro Framework entry turned up. And it is wonderful. It is one of the latest Tahoe II boards from Device Solutions. I installed the drivers, plugged it into the laptop and got my first program working in minutes.

My first program just displays a picture of the team (as well it might). Next step is to see if I can get the touch screen going, then I'm going to play with the Zigbee wireless networking(we also got a Zigbee adapter for the PC) and interface some sensors and, and, and.....

Good thing I've finished my marking.

Update on Friday, January 23, 2009 at 02:55PM by Rob

I've just discovered that to get the Zigbee board to work on the PC you need to have USB drivers for the carrier boards as supplied. You can find them here: http://www.digi.com/support/kbase/kbaseresultdetl.jsp?id=2138

Update on Friday, January 23, 2009 at 07:45PM by Rob

I've done some more playing. Some notes you might find useful if you are building something for this competition:

Don't try and build a Console application for the Tahoe board, for some reason it won't work.

The PC connection for the Zigbee board simulates a COM port (in my case it was COM17). This should be configured at 9600 baud, 8 data bits, no parity, 1 stop bit. You will need a USB cable with the big connector on the back to power up the interface.

The Zigbee board on the Tahoe board is connected to COM2. When creating the SerialPort instance to talk to the Zigbee device you can just use the simplest version of the constructor, which just takes the name of the port to open.

I've made a couple of really simple programs that should get you started:

XBeeTest is a program for the PC that creates a COM port and implements a tiny terminal that will talk to a Zigbee board on the USB port. You can use Device Manager on your machine to find out which serial port the board is connected to (the program is set up to use COM17). The one button sends the AT command +++ to start a remote session. If all is well you should see OK appear in the TextBox. If you select the TextBox and type commands these will be sent to the Zigbee device and the responses will appear in the TextBox. This does not perform the actual network connection. You have to use the protocol described in the manual here.

MicroXBee is a program for the Tahoe board that connects to the Zigbee device and resets it. When you press the Select button in the middle of the keys the program creates a SerialPort and sends the +++ command and then displays the "OK" message that comes back. Again, it doesn't tell you how to do the comms, but it will get you started sending and receiving them. It assumes that you have installed the drivers for the board.

Comments

[Michael Schwarz]

Did you had a look at my Zigbee library? Would be happy on any feedback...

http://www.codeplex.com/mschwarztoolkit

[John]

These are actually 802.15.4 modules, I believe, rather than Zigbee.

[Rob]

You are dead right. Sorry about the confusion. I assumed that XBee was an implementation of Zigbee.

[Michael Schwarz]

Well, my lib should be called XBee as Digi is implemented XBee API/AT commands that are build on top of different hardware modules, one of them is Zigbee.

[Rob]

Ah. That clears it up. It also means (I hope) that we could switch our devices from XBee 802.15.4 modules to full Zigbee without having to change the software, since the AT commands work on both platforms.

[Aby Mammen Mathew]

I came across your post and was trying to interface with the A/D on the xbee module. They were in fact series 1 and have lot of incompatibilities with the series 2 in terms of the command set.

However when i get time, will convert Michael's lib for series 1.

I did a small conversion to just pass commands via the uart with some modification to Michael's lib.

I found the Tahoe board an overkill and not truly a platform for embedded systems. I like the SJJ module better.

[Rob]

I've found that the first thing you must do is upgrade the software in the Xbee devices themselves. Then things get a lot easier. We are using the Tahoe board as a console and it works well in this mode.