Synopsis

First, an important point is that, since we will be using the PWM technique to control the brightness of the LEDs (Red, Green and Blue separately), make sure that you connect the Red, Green and Blue Anodes of the RGB LED to three PWM supported pins of Arduino (assuming you have a common cathode RGB LED).  PWM is a technique where the amount of power delivered to a device can be controlled accurately and efficiently. PWM technique can be used to control the brightness of an LED, the speed of a motor or the direction of a servo motor.

 

<<right-click to download image>>

flopsy3

Parts List

  • R1 – 1M
  • R2 – 10k
  • R3 – 760Ohms
  • R4 – 1.5K
  • R5 – 100Ohms
  • C1, C2 – 15pF
  • C3 – 10uF
  • C4 – 0.01uF
  • C5 – 0.1uF
  • S1 – 5 DIP switch
  • V1 – 5V
  • U1 – AT89C51
  • U2 – HT12E
  • U3 – LM555
  • U4A – 7408 (AND gate)
  • Q1 – BC547