I made this project because I wanted a way to automatically control the speed of a DC fan according to the temperature read by a LM35 sensor ... at the output of the PWM pin on the Arduino board. I ...

The build uses a Freeduino paired with an external GSM modem for communication and an LCD to display current ... [kohleick] connected two temperature sensors: one directly to the Freeduino ...

and an Arduino. There’s also an LCD display and a FET to control the heater. The idea behind a PID controller is that you measure the difference between the current temperature and the desired ...