Hi, I will show you how to build sound reactive mood light using only Arduino Uno, RGB LED strip and a few common electronic components.

Step 1: Materials needed

Sound reactive light
Sound reactive light
Sound reactive light
  • Arduino Uno
  • RGB LED strip (common anode)
  • breadboard
  • LM358
  • 12V DC power supply
  • 9V battery
  • power cable for arduino (9V battery connector, power jack plug, cable)
  • 3.5mm stereo jack plug
  • 3.5mm jack splitter
  • wires
  • solder


  • 3x BD139 or similar (for longer strips you should use more powerful transistor + heat sink or RGB LED strip amplifier, you can edit the cirquit and use MOSFET too)


  • 2x 10 uF
  • 1x 47 uF
  • 1x 47 pF


  • 1x 33 kΩ
  • 2x 100 kΩ
  • 1x 1 kΩ
  • 3x 150 Ω
  • 3x 5.1 kΩ

    Step 2: Wiring

    Sound reactive light
    Sound reactive light
    Sound reactive light

    For wiring up components on a breadboard just follow the schematic. For transistors I've used universal PCB, because mine have too strong connections.

    Signal is connected to the left channel contact of the jack connector, but you can use right instead. Ground is connected to the ground of the connector.

    As a source of 12V you can use some 12V DC power supply or lead-acid battery, but keep in mind that 1 meter of RGB LED strip can consume up to 15 watts.

    Arduino onboard LED indicates limitation, if it is flashing, you should replace R1 with resistor with less resistance (10 kΩ).

    Step 3: Programming Arduino

    It is using Arduino FHT library, just download it, unzip into Arduino libraries folder (Documents\Arduino\libraries\) and restart Arduino IDE.

    After library installation you can upload the programm.

    If you want, you can change speed of the fade effect by modifying DELAY constant.

    I am using blue for low tones, green for midtones and red for high tones, it can be changed by swapping LED_R, LED_G and LED_B in setup function.

    Sound reactive light
    color_organ.ino4 KB
    Sound reactive light
    color_organ_2.ino5 KB

    Step 4: Completed project

    Sound reactive light

    Now you can connect power to arduino and LEDs. After that LED strip should light up and react to a signal comming from the audio jack.


    Tag cloud

    make build easy simple arduino making homemade solar laser printed portable cheap mini building custom cardboard wooden create super lego turn paracord chocolate your paper light intel