Using an add-on card to the already existing avr ethernet board we build a weather station. That is: A weather station with a build-in webserver. My original plan was to have sensors for temperature, air pressure and wind. I started a prototype and it worked very well except for the wind measurement part. I plan to improve the wind measurement hardware and add it at a later point in time.

Each fan turns off when the temperature drops 5 degrees below its turn-on temperature. For example, if the dial is set to 80 degrees, the fan turns on at 80 degrees and turns off at 75 degrees. This prevents the fan from cycling on and off rapidly, which would occur if the fan turned on at 80, started to cool the cabinet, and then immediately turned off at 79.

This is a very easy and fun to build project that will allow you to control up to eight external devices through your computer's parallel port. You may for instance control different appliances such as lamps, computers, printers, tv sets, radios, music systems, air conditioners, air fans, garden sprinklers and anything else you can think of, all through your computer. You can do a simple test by connecting a LED directly to a ground and any PINs 2 through 9 of your parallel port. The voltage on the parallel connectors is around 4.5V but it drops to around 2V once you connect the LED. You may use a 100 Ohm resistor if you want to, but it is not necessary since the current is very low.

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