13. Applications and implications

This week’s assignment was to address the below questions about our final project:

1. What will it do?

A motion triggered instrument that translates hand motion (input) to sound (output). The instrument I chose is the piano. Each row represents one octave, moving your hands left and right in one row triggers sound from one scale in one octave (C scale in either octave 3 or 4), and moving your hands up or down triggers the same key in a higher/lower octave. I will use two Ultrasonic motion sensors to create a linear grid (approx. 70cm wide). Each octave will have a sensor, and each key will be programmed to play when the sensor detects an object (hand) within a set distance. For example, 10-20 cm will play keys E3 or E4 depending on if your hand is at the higher or lower octave.

2. Who’s done what beforehand?

There are many examples for products, apps, and art exhibitions that use motion to trigger sound, below are examples of some:

3. What will you design?

2D Design:

Design the board and support using Fusion 360 Cut using CNC

3D design:

Design the case to hold wires/electronics using fusion 360 3D print using Ultimaker


The PCB design needed for the processor (ATemga328P), inputs and outputs Ultrasonic sensor grid

4. What materials and components will be used? What parts and systems will be made? What processes will be used? How much will they cost?

Instrument Structure:

The board and support will be designed in Fusion 360, made from plywood and cut using Shopbot CNC. I will engrave the board to create the desired surface.

Wires/electronic case:

The case will be 3D printed using PLA filament in the Prusa 3D printer, and designed using Fusion 360.


I will be using Eagle to design the PCB I need for my final project, and Carvey milling machine to produce the PCBs on FR1 boards. Additional processes I will be using are: soldering the electronic components and programming using Arduino IDE.

Below is the list of components I will be using, the list might change if additional components are necessary.

The total price should come to SAR 150 - many of the materials listed are available in the lab so the total cost will be less than listed.

Electronic components:

The main electronic parts of Maestra is the motion sensor (input) which triggers sound (output) from an SD card that has piano keys stored. There will also be a speaker to play the audio. The microcontroller I will be using is ATemga328p.

5. Where will it come from?

All materials and electronics components I mentioned are available in our lab (sourced from different local and international stores). If any components are unavailable, I will order them online from either local or international sellers.

6. What questions need to be answered?

  • Where will the electronic components be placed on my board?
  • What is the best way to engrave/design the instrument board so it can be a useful visual guide for users to know where to place their hands?
  • How will the music sound if more than one object is triggering sounds?
  • Should the sound output be limited to one at a time?
  • How much will the instrument board weigh?
  • What is the best way to place the sensor on the board? 3D printed stand?

7. How will it be evaluated?

Maestra will be evaluated based on the engagement between the user and the object, and the interest of users to continue exploring sound using this object. On a technical level, the project should be fully operating without any lags in feedback between sound/motion.