AVR-Chat

Kong wrote:

>there's also a wireless weather station based on pic16f873...
>http://www.circuitcellar.com/
>  
>
  Speakjing of wireless, Atmel isn't suppoting it YET, though I have 
little doubt that they will come on board eventually:


  Check out Zigbeee wireless mesh networking.   IEEE 802.15.4 standard 
for a 2.4 Ghz sprread specxtrum mesh network protocol which offers 
self-forming, self-healing network deployment, and operability withoiut 
interference inthe vicinity of other wiresless 2.4 Ghz services such as 
802.11x and Bliuetooth (no intereference ineither direction, accoirding 
to the specs)

  A quick overview:   2.4 Ghz, 250 Kbps, originally designed to support 
wireless sensor networks.  In the  base conficuration, it offers 75 
meters range, node to node.  Since the network is a mesh, so long as no 
node is any further than75 meters from any other node, the network 
maintains integrity, regardlessof overall distance from "first node" 
to:"last node."  You can alos use RF power amplifiers and hihger end 
antennae to achieve up to just shy of 1 mile of range.,

   All Zigbee capable components I have seen so far are completely 
self-contained,.  Most are embedded on a 16 or 32 bit processor, but 
have saparate ROM-based Zigbee networking stacks included, so all you do 
fromthe processor is push a few values into dsome setup registers, and 
start passing the network data.   Zigbee protocolhandlesall addressing 
issue and so on, so if a message comes acorss the network for yoiuyr 
processoir,m it gets an interrupt teling it so, with no other overhead 
inyour softeware at all.

  There are also add-on Zigbee "processors" which can be hung off the 
side of your existing uP.

    Zigbeee is very inexpensive.  One vendor will soon (1Q 06, 
allegedly) be shipping a 12.5 Mhz,m 16 bit processor with embedded 
Zigbee hardware/firmware.  Included are hardware encryption 
accelerator,m hardware based random number support,  a wide range of  
typical embedded processor peripherals, all for about US$5 qty 1.   
Believe it or not.

  There are more and more vendors jumping on the Zigbee bandwagon. My 
understanding is that Zigbee is huge in Europe (though i have no 
specific informaiton on that).

   Jennic is one vendor offering both embedded processors enabled for 
Zigbee, as well as Zigbee addons.  www.Jennic.com, IIRC.


Tom