This is my Magical Music Box which converts music into a light show. When i was daydreaming what to make for my final project, i wanted something that would make a light show for any song simply by hearing it.
Materials used:
1x arduino
8x 1k ohm resistors
5x 10k ohm
7x 560 ohm
3x 150 ohm
1x really really really big potentionmeter. so big its basically an on/off switch….
4x RGB LED’s
8x .1 uF capacitors
2x LM358N op amps
1x LM386 op amp
1x microphone sensor
2x 9v batteries with battery holders
approx 2 miles of wire
some kicking music to show off with
Real simply, i used a microphone circuit for input, amplified it, ran it threw a potentiometer so i could control how senstive it was to ambient noise then split it into 3 band pass filters to tune out other frequencies then used that as an input for my arduino. A simple conditional based on that input controlled 6 digital out pins with each pin connected to a single input on 2 separate red, green, blue LED’s. So since each LED has 3 inputs, thats 6 pins to control 4 RGB LED’s.
I ran everything off of 2 nine volt batteries, one as +9v and the other as -9v. Here is a simple power schematic to be used in conjunction with the schematic above. I used the arduino for all my grounds.
Now for the gritty details. I used the PDF titled Op Amps for Everyone, which i have included a copy of at the end of this post, to learn how to make a band pass filter. Specifically i used the Sallen Keys band pass filter located in section 16.5.1.1
For more detail: Nick Smith – Magical Music Box
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