32 touch sensitive, haptic feedback devices communicating with single PC

Projects General Guidance
1

So I'm trying to figure out if I'm thinking about this in the correct way, as I have not done a project at this scale.

Goal:

32 devices mounted to a wall
Each device is touch sensitive, probably using the AT42QT101X board from Sparkfun
Haptic feedback provided using DRV2605L and an ERM motor

My original thoughts:
Each device has a Nano to control the touch and haptic as a separate "unit"
Each device has an output pin going to an input on a central Mega
Each pin triggered on Mega sends a serial string to the PC (this is required for the software running on the PC)
Single central power supply (12v ?) with a wire to each nano to power them
Total of 3 wires to each "unit" Ground, signal, and power (I don't have much room for wiring so minimal amount of wires to each device is preferred)
Considered NRF or something for wireless, but trying to make this all as simple as possible

Looking for some thoughts on this, am I crazy thinking it will work this way? will I have power problems I'm not thinking of once i have this many devices?

Really any thoughts or help would be great.

Thanks so much!

2

Adding Nanos only makes sense fwith special communication. Otherwise 3 wires are also sufficient to connect a module, no need for adding controllers.

3

DrDiettrich:
Adding Nanos only makes sense fwith special communication. Otherwise 3 wires are also sufficient to connect a module, no need for adding controllers.

To connect the touch sensor and the haptic controller I'd need more wiring though, right? One of the other reasons for the nano's is because I can't connect all 32 haptic controller to i2c because they addresses are unchangeable, and if I put in an i2c multiplexer then i need to run all the i2c wiring to each device as well...

My thought was doing it this way I'd have very simple code, and each unit would be independant.

4

I missed that you want to add the motor to each sensor as well.

If I2C is in use by the haptic controller, you can daisy chain the Nanos and use bit-banging for sending the states serially to the master controller.