Zigbee baby monitoring system

Hey all, I've got a project in which we have to design and build a wireless baby monitoring system that will alert the user when the baby leaves the house. Ive been researching Zigbee products however I'm still a little unsure about a few things. The general idea that I've come up with is install small motion sensors around the endpoints and when broken a hooked up Zigbee end device will send a signal to the coordinator which then will in turn light a led or play a small sound.
I can't find many webistes that sell a Zigbee coordinator. Im then unsure about how to program it as information is a little vauge.

Does anyone have any thoughts, idea's, experience in this area or any helpful comments?

Hmmmm... for some reason, it ate my first response. Let me try again.

While I've never used a Zigbee, according to Sparkfun's Wireless buying guide (http://www.sparkfun.com/tutorials/128), Zigbees are not recommended for their steep learning curve and unimpressive performance. Others may disagree and Sparkfun is not perfect in their assessments, but I usually trust their judgement on these things.

However, I have used XBee's and the Nordic wireless transceivers successfully. The XBee is a somewhat expensive (~$20), power hungry IC that is insanely easy to use with great range. The Nordic wireless is less expensive (if you purchase the parts separately and put it together yourself ~$10), much smaller, with good performance but is more difficult to use and assemble (QFN packages, I tried to solder one last night - epic fail).

I recommend that you look around at the link above and see what works best for you. If you have any questions after looking at the link, particularly about the XBees and Nordic, feel free to just shoot me a message.

wicked thanks for the help mate i appreciate it. i'll look into it.. how do you program the IC ie in C code

For both the XBee and the Nordic systems you need a separate microcontroller. The XBee, in its simplest form, is a pipe for UART communication. It is literally as easy as hooking up the input and output on the XBee on both ends to the IC's and then acting like the ICs are directly connected with a wire. With the Nordic, at least the one I used, you communicate with it via SPI. You have to set it up, change certain settings, and then tell it what to send and when it should listen, etc. It's not nearly as transparent as the XBee.

So, basically, you can use any microcontroller that communicates with a UART or SPI. For my two applications, I used a PIC16F690 with the XBee and a PIC16LF877A with the Nordic. I used C with both of the PIC microcontrollers, but all of the examples are in assembly, which is just a minor annoyance.

hi,
my suggestion is tu use DIZIC module as coordinator,


good luck. )

Hi, I just wanted to point out that the XBee does use Zigbee as the underlying technology. The XBee is Digi's Zigbee module solution. In general, they have done a very good job of packing it to be an easy out-of-box solution for this type of application.