Made a very short demo vid

http://youtu.be/9q1rD7xBD10

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

Well, Lets hear it

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:

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

http://hackaday.com/2014/12/14/sqonkbox … ore-140610

Here are some quick calculations for the resistors in series.

In this photo,
R1 = 10000
R3 = 32,588
R4 = 8,190
etc...
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%.

Yeah,  i was wondering what those black sticker like things were on the other side...never seen that before...

.

8 should do it.

A4 (440Hz), R2 = 113.9775
B4 (493.9Hz), R2 = 96.082
etc...

8 trimpots,  I'm guessing?  I will probably use a breakout box anyways...

The frequency calculation is well known. Just put in some values until you get the freqs you need.
The problem I can see is that you will need a lot of trim pots to get those absurd values. Also that the duty cycle will shift slightly, but the effect may actually be interesting.

http://www.ohmslawcalculator.com/555-astable-calculator

Yes,  I believe I've used that circuit before!   I got it from Forrest Mims toy organ schematic.  I even made a "polyphonic" version by doubling the circuit,  but It was only arbitrary notes like you said....(also had photoresistors controlling pitch for fun)

I'm liking this idea!

Now i just need to figure out which resistors to use to generate the chromatic scale,  I'm guessing I'd need some trimpots,  too.  I will Google this, I'm sure it's out there somewhere.

Thats odd, but don't worry. I believe they were/are nothing more than pull-ups for the latch pin on the 4021 (or something). And if you liked my idea, you would pull it out anyhow. Here is a quick and dirty keyboard mockup. in all honesty, it could probably fit inside the controller housing if you tried.

Note: This will not be traditionally tuned to any notes. It will just make different noises depending on the buttons pressed. It will also be monophonic if you couldn't have guessed. Have fun.

No resistors

Thanks guys,  not sure what I want to make,  so I like hearing the ideas!  The 555 keyboard idea sounds cool!