Phase 2 Step 2: Arduino + conductive ink + servos + sound (technical questions)

Hi Ed, how’s it going?

I’m writing because I’m technically stucked with my project.

The goal:

As you know, I want to do a keyboard (or launchpad) with the conductive ink.

When pressing the keys, I want to trigger one MP3 and move a servo (at the same time) (and with the possibility of triggering more than 1 key/sound together).

Arduino conductive ink

My current situation:

I achieved to set up the capacitive sensor with 2 keys to trigger a sound on a piezo using the capacitive sensor library.

Where I’m stucked.

1. CODE:

I have been following several tutorials of how to use the conductive ink as a Capacitive sensor. I have bought some 1 Megohm resistors for absolute touch to activate the keys.

Capacitive sensing.

Bare Conductive Tutorial.


I’ve found some examples of a capacitive piano (pretty easy to do). This is a great tutorial, explained step by step.

All the material: circuit, breadboard design and code here:

And an example of capacitive sensor + servo

I tried to add the servo library, but I can’t achieve to connect the 3 parts (capacitive sensor/Sound/servo). It looks like there’s a conflict between the flags of the servo and the sensor.

I also tried to use the code I prepared before using the flags, but it doesn’t work either.

2. Hardware:

As you know, I’m trying to avoid the use of a computer. I have found the Simple SD Audio shield to trigger MP3 sounds hosted in an SD card (using it as a “hard drive”).

List of Sound libraries and hadware here:

Do you think it can work? or will I still need a Pi or a computer?

On the other hand, I’m sure I will need an Arduino Mega for doing it, but I’m afraid that there will be no space for the pins of the keyboard and the Servos.

I would like to attach as many servos as I can (remember that I have 28 Pez dispensers. I know it’s very difficult to connect them all, but I would like to do it with as much as possible). I though that it can be a good Idea to connect my arduino UNO with an Arduino MEGA. Here:

Do you think it’s enough with one MEGA, or will I need to link the 2 arduinos?

3. Software

I have found a good example of a keyboard/launchpad like what I’m trying to do (without the servos).

This guy is using processing, arduino and Python for the programming (I don’t understand why Python if he’s using a computer, but anyway).

Is Processing code needed in my case, or it can be done only with the arduino software?


QUESTION 1: the code (or the logic behind it). I don’t understand the process. (I’ve found conflict between the different values used for the Millis in the sensor and the flags of the servos).

QUESTION 2: Any opinion about the hardware? the SimpleSDAudio seems to do what I need. UNO? MEGA? OR BOTH?

QUESTION 3: which software needs to be involved?


Thanks Ed,




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