Project1 : 12v or 24vdc led strip dimmer
For dimming ledstrips you need to have a pwm controlled output and the arduino has some outputs you can use
as a analog output who produces the analog value as a pwm controlled output.
In this example we controlled the intensity of the ledstrip with a simple potentiometer.
The circuit: the connections with the arduino are labeled with flags.
led1(pin9) and led2 (pin10) are the minimum maximum output indications
pin 11 is the pwm output who has to be amplified with a mosfet BUZ11 or other type N mosfet
A0 is de analog input for the potentiometer