Here are some quick calculations for the resistors in series.

In this photo,
R1 = 10000
R3 = 32,588
R4 = 8,190
C2 = 10nF
R1 = 10000

The calculations are rough, so the freq does move around about 1 hz either direction, but the duty cycle stays pretty close to 50%.

Last edited by Jazzmarazz (Mar 5, 2015 4:26 am)


Here's a 555 based circuit.  There's a 30 minute video explaining how it works as well. … ore-140610

Last edited by RatShack (Mar 5, 2015 4:41 am)


So I finally got around to working on this project and I've built my first prototype.  I call it the Noise Entertainment System and it is basically the toy organ circuit with a light sensitive photocell to control the overall pitch.  The buttons are not tuned to any scale,  just random notes that change depending on light conditions.

I have a lot of little changes that I want to make to the next version:

Brighter leds underneath the Nintendo logo
Smaller switch
Smaller jack?
More resistance between each button to make the pitch change more noticeable between buttons
Overall neatness improved upon

I also want to add a LFO circuit to the next version that I make,  though it was quite a challenge fitting all the components inside the tiny controller...

Here it is:

Dallas, Texas

Well, Lets hear it smile


Going to post a vid tomorrow,  eating some left over pizza and hitting the hay!


Made a very short demo vid