deskthority

Hi,
I'm looking for a possibility to use different Buzzer-Buttons or contacts in an art-installation as keyboard-replacement.
I want to connect the wires of these Buttons with a controllerboard and connect this controller with USB with a computer.
Then a Push on "buzzer A" should send a "keypress 1" to the computer.
A Push on "buzzer B" should send a "keypress 2" to the computer.
And so on.
This should work without a driver.
For the computer it must be detected as a normal USB-Keyboard.
Can you recommend me a Board for this?

Thank you

Michael

You came to the right place

First things first, let’s just make sure we’re not dealing with an http://xyproblem.info/

You want a buzzer and a computer to do something else. Did you choose a keyboard as input because your software already supports it or because it seemed the easiest way to get input to a computer without drivers?

Is the computer simply spewing out commands to other hardware on a network, or via midi for sound or dmx for lighting?

All of this is easy, so no stress.

Hi,
there's a animated visualization on a screen connected to the computer.
With the number-keys you can switch between the animation-sequences.
This has to work with a normal keyboard - and with this "special-keyboard-installation".
So I think it would be the easiest way.
The second variant I'm checking is via dmx - but I would prefer the keyboard-way...

Michael

cool.

Do you have a part number for the buzzer you intend to use?

Unless there is a problem with space or size, you could use an actual keyboard and remove the switches, then mount your preferred switches to whatever surface you want them on, and run wires from them to the original contact points on the keyboard PCB, which you could hide away somewhere.

The computer should not see any difference between this new "keyboard" and the old one in its original configuration.

@fohat, that was my initial intention - but then I found some developer keyboard boards and started my search for a "more professional" way...
I don't know, which buzzer or buttons I'll take - but they will only open/close a circuit?!?

How many buzzer-buttons?
And you intend to connect button and buzzer in series, right?

If they are not that many, you could get a microcontroller board and open source keyboard firmware for it and modify the keyboard matrix scanning code to have n inputs instead of n×m rows and columns.

A normal keyboard contains a matrix that is scanned by strobing each column in series, and for each strobe read the rows. I suppose that for a buzzer and button in series, the strobing part is something you want to avoid.
I think you might also want to use a transistor per button/buzzer/line also, so that you wouldn't use the microcontroller as a current source/sink for the buzzer.

Okay, let me go ahead and my my thoughts down on paper. I would suggest you use some form of arduino and run qmk_firmware.

The software is at: http://qmk.fm

Take a look around their site and the instructions. If it looks like too much or you need any help just ask. I'd be happy to build something along with you in parallel to help you get started if you need.

Welcome to Deskthority!

Thank you all for your help!
Very good inspirations and startingpoints for my research.
Next I'll try a sketch and a plan of my full installation.

This is my planned setting: The Browser-Application should work "in this device" and in a normal browser.
That's why I would prefer the keyboard-input...

Look up WS2812 strips. Each LED is individually addressable.

Here's something I built with it in about 12 hours at defcon: