8x Relays with "Makey Makey" approach

Projects General Guidance
1

Hey!

I would like turn my Arduino into a "makey makey" and controll 8 relays with them.

I'm a beginner and only have the Arduino UNO board right now.

Is it possible to use the digital inputs/outputs as analog inputs? Or do I have to get another board with more analoge inputs? On my Arduino UNO board I only have A0 - A5, 6x analoge inputs, which means I theoretically only can have 6x "makey makey" buttons?

Is there a way to do what I want with the Arduino UNO board, or do I need another board? If I need another board, which one would you recommend for this? Or if there's a way to use digital inputs/outputs as analoge, how?

Thank you very much for your help!

2

What is a "makey makey" button?

Please consult the products comparison page at this website (https://www.arduino.cc/en/Products/Compare) to select the Arduino that meets your needs. Analog inputs can be used directly as digital inputs. Digital inputs can not be used as analog inputs. On the UNO 6 AI pins is all you get.

3

niss3:
I would like turn my Arduino into a "makey makey" and controll 8 relays with them.

A $2 Nano has eight analogue inputs.
Leo..

4

Hi,
I think this is the OPs device.

I think the OP wants to emulate~~.~~


It looks like it has on board processing of some sort, but does it needs lots of analog inputs on the Arduino to work?
A brief read of site says it is USB connection to PC, but there may be a other versions I haven't seen.

OP needs to tell us the model of the Makey Makey.

Tom... :slight_smile:

6

Hey everyone and thank you all for your answers!

My vocabulary isn't that good so I'm a little bad at explainig. What I ment with "makey makey" I think can be explained as "CapacitiveSensor". I think this is what I want to use to achieve what I want, and it can only be done with analog inputs.

So as adwsystems said I've also read that Digital I/O's can't be used as analog, but analog can be used as digital. That doesn't help though so I think I will need a new Arduino board to achieve what I want.

Now what caught my interest is what Dela_G said. What is a 32u4? I've seen so many "tutorials" of how it's done, and it seems they all want to use the analog inputs for some reason, coupled with a resistor.

I'll experiment some and see if I can get it working with digital. I don't really understand what the difference between them is.

8

You're right Delta_G! I though they were the same thing. Apparently capacitive way doesn't need you to be connected to ground? But Makey does.

I tried this:
https://www.pjrc.com/teensy/td_libs_CapacitiveSensor.html

It works with digital inputs!

I have to go to bed now, but I will keep playing around with this!

9

For capacitive sensing your project must be grounded properly (so not battery powered or so).

Your body is technically not grounded but it's capacitance is big enough, and losses of charge to the air big enough, to effectively act as ground, which is how you can sense touch. It's after all a change in capacitance that you're trying to measure.