Clipping: "Arduino: LCD Thermometer with optional Alarm"

Cool link to a LCD thermometer using arduino:

Arduino: LCD Thermometer with optional Alarm

 

 

Stuff

And there are more coming on! ;-)

About the use of a photocell

Following good information on the use of photocells with arduino:

Analog Voltage Reading Method

The easiest way to measure a resistive sensor is to connect one end to Power and the other to a pull-down resistor to ground. Then the point between the fixed pulldown resistor and the variable photocell resistor is connected to the analog input of a microcontroller such as an Arduino (shown) [keep reading]

Notebook fan on arduino

Just to remember: Connecting notebook fan to arduino (RPM counting)
http://playground.arduino.cc/Main/ReadingRPM