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 ...

If you want to use a bi-polar transistor, don’t forget to add a resistor (~1KΩ ) between Arduino D10 and the base terminal of the transistor. Tags Electroschematics. T.K. Hareendran. About T.K.

The Arduino then controls the state of the LED using the active high enable line from the column multiplexer chip. [Alex] wanted more than just a static image to show off on his new display, so he ...