You can control the brightness of these LEDs using variable resistors VR1, VR2 and VR3 respectively. Parts Needed. Arduino UNO board – 1 ; 5mm LEDs Red, Green, Blue – each 1 ; 100K Variable resistor – ...

It is a pretty common first project to use an Arduino (or similar) to blink an LED. Which, of course, brings taunts of: you could have used a 555! You can, of course, also use any sort of oscillato… ...