I build simple electronic noise machines in my free time.  I seem to work with the 555 and the 40106 chips a lot... drone machines and punk consoles,  metronome circuits,  lfo's,  etc.  I occasionally build a kit and circuit bend stuff also...  Basic DIY electronic stuff.

I have an extra NES controller that I would like to incorporate into this work.  I'm thinking the controller would look pretty normal,  but it could be hooked up to some sort of noise machine,  and pressing the buttons would somehow alter the sounds being generated.

The problem is I can't figure out how I could execute this.

I did find the following from the Ninstrument website...  which seems helpful,   but I don't have a modular synth or anything like that,  and I'm not interested in using the program that this schematic is intended for.




I also have an Atari Joystick that I would like to incorporate into a different,  yet similar project. 


Can anyone help?  Any ideas?

What did you have in mind?

A cheap Arduino Nano (clone) has all you need to:
a)interface to the controller
b)code a simple PCM/PWM tone generator - the 328 has enough timers to generate some pretty complex waveforms

Yeah,  unfortunately nothing that complex...  I don't know Arduino or anything like that.   I was just thinking some sort of crude noise generator like an Atari Punk Console or Drone machine.  Maybe down the road one day I'll get into Arduino.

That sounds cool though,  someone (else) should build that!

You need to figure out what you want to control, but you've basically got 8 buttons.  Since you work in the realm of discrete ICs you could probably wire it up with a 4066 quad analog switch to control some other circuit.

Also, the NES controller works by grounding signals fed into a shift register - the inputs at the IC are normally high when not pressed.  It's possible to remove the 4021 and cut the pull-up resistors, then you have a controller with 8 N/O buttons.

Note that all the buttons are going to have a common ground or V+ depending on how you wire it, so you'll need to factor that into your design.

Last edited by RatShack (Mar 5, 2015 2:29 am)

The problem with the Ninstrument circuit is not that you don't have a module, but that it works backwards from what you need. The gate inputs in that schematic are used to trigger button presses, not button presses triggering outputs.

How do you want to sounds to be altered? Different frequencies? Vibrato? Filters? Do you want a button to bridge a different resistor value on your 555 timer...what?

So playing off of what ratshack said, all of the buttons have a common ground. Lets consider this not ground, but a common connection instead. If you pull the IC and use the ground point as the common connection as in this picture, then you can build yourself a resistor ladder to use the controller as a keyboard connected to a 555 timer.

If you wanted to keep the controler stock, you would need to convert the serial stream back to parallel requiring a shift register and a clock - you seem to have the 555 timer worked out so that should be easy enough for you.

Using the 8 discrete logic outputs gets a bit more creative. You could use them to charge/discharge caps on a few 555 oscillators, mixed to a single output?

I'm going to have to learn more about that chip (4066) and see what it can do...

But I like more the idea of using the controller as 8 N/O buttons,  then I could turn on and off different oscillators on a 40106 or something like that.  So I would totally desolder the 4021,  remove it completely and cut off the 2 resistors? 

After checking my controller,  it does not have any resistors on it,  like the one in the picture does...

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

No resistors

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.

Last edited by Jazzmarazz (Mar 5, 2015 2:51 am)

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.

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

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

8 should do it.

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

Last edited by Jazzmarazz (Mar 5, 2015 3:21 am)

RJL wrote:

No resistors

Flip it around. The "resistors" are on the other side in black. I forget what the technique is called, but it has a very broad tolerance. Suitable for this application where the value is flexible.

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

Last edited by RJL (Mar 5, 2015 3:27 am)