a simple sample machine (as independent as possible) - any ideas ?


I want to build a box with 12 big buttons (http://www.arcadeshop.de/Illum-Buttons-Jumbo-Dome-Button-98-mm-red_505.html), that when you push a button, a sample is triggered and played and while the sample is playing the respective button is lid up. This is meant to be used by children from 4 - 15 to "jam" with a jazz band.

So my initial thought on how to approach this was to make a sturdy wooden box with an arduino uno inside that would connect via USB to a laptop (hidden somewhere else) and trigger samples through a max patch I've made. I also need to be able to change the samples that are being triggered (between each gig).

Before I go ahead and order these rather expensive buttons and components, I just wanted to hear if anyone here has any suggestions on this. Would there be a not-too-complex way to make these boxes more independent and maybe even without a laptop and Max? I thought about using a Raspberry Pie, but I'm not quite sure if what I want to do is possible with a Raspberry.

Any ideas, suggestions or thought are very very welcome.

Thank you,

You may be running out of pins: 12 buttons and 12 lights (12 volts according to the site), so also 12 transistors to drive the lamps. Maybe some switch with LED would be easier??

Maybe easier to just get a Mega for $29 or so and have plenty of pins?

Or you could put multiple buttons with resistor network into 4 Analog inputs, have JUST enough output pins with 2..13 + one analog as output.

The flexibility of the laptop for storing samples and high quality playback is good, I think.

Think about what you want to happen when more than one button is pressed etc.

My first thought is that big child-friendly buttons that illuminate when pressed could be implemented entirely in hardware, and the buttons and enclosure are the only part I'd expect to spend any money on. My second thought was that if you simply use each button to switch on some sort of cheap playback device then you could do it without any complex electronics. That could be a cheap old laptop with certain keys wired up to the switches and running a software synthesizer application, or something like those recordable greetings cards that play a short low quality sound track when they're opened.


Yeah I’ll probably have to make a resistor network in order to have enough inputs for the buttons. But i’m not sure that will work, because it should be possible to push more than one button at the same time and then start the correct samples for each button at the correct time. With a resistor network I don’t think that would be possible, but I might be wrong?

I could go the Mega-way, yeah - and I will do when I’m absolutely sure I can’t do it on the Uno.

Yeah, that was my initial thought as well… it would quickly become a very complex job to do if I had to do more than that in hardware.

Actually I just found out that you can get a so called Wave-shield from Adafruit! It’s only 22$ a piece and it seems to be exactly what I need if I want to avoid using a laptop: http://www.adafruit.com/products/94

That’s pretty neat, don’t you think?

I to would have gone for the wave shield or playback from an SD card. No PC required!

But why 12 buttons and not 8 (are there only 8 notes in the scale?. Well you have seen the sound of music :slight_smile: )