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
Step 2: Wiring
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.
Step 4: Completed project
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.