This is an easy tutorial showing how you can control the brightness of an LED or adjust the speed of a DC fan using Arduino Board, a small BC547 transistor and a potentiometer. In my example the whole ...

“You can’t put new wine in old bottles” – so the saying goes. But you would if you’re a hacker stuck with a radio built in 2005, which looked like it was put together using technology from 1975.

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. I had a few problems with the PWM part mainly because the ...