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Rondine - a Zigbee temperature client
With the advent of summer weather in June 2008, I had yet another concern that the upstairs air conditioning was not performing correctly. The best way to monitor the performance is to monitor inlet and outlet temperatures along with attic ambient. Hopefully this will highlight any problems we may be having with air cooling or air heating.
The device chosen to do this is AVR based because I had the hardware and tools, the ubiquitious One Wire DS1820 from Maxim which I have lots of experience with. A major plus is the fact the probes are pre-calibrated at the factory.
Unique for me is the addition of more than a single probe to a wire. The former QYX terminal I hacked for this purpose only had one convenient port pin. I rewired an old network/ethernet switch to serve as a passive one wire hub. All the probes plug into the hub and one probe comes out of it to the AVR subassembly. This AVR assembly has a Digi Xbee module for wireless connectivity.