# Title Team Members TA Documents Sponsor
22 Electric Violin Audio Processor
Alex Seong
Scott Foster
Wei Gao
Jeff Chang design_document3.pdf
# Members
Wei Gao (weigao4)
Alex Seong (aseong2)
Scott Foster (scottbf2)

# Problem
Currently available piezoelectric violin pickups tend to be either cheap and not good, or good and not cheap. Some of these pickups can be purchased for $100 or less, but tend to deliver a poor, “tinny” or “nasal” sound. At the other extreme, pickups like the Starfish and Barbera models provide a professional-level “rich” sound, but are very expensive (the Starfish costs at least $300, and the Barbera at least $450). These high-grade pickups also tend to be of low availability.

# Solution Overview
An electric violin pickup system which provides control over the volume level and timbre of each string prior to the main instrument output.

# Solution components
## 3D printed pickup bridge
A significant part of the cost of high-end pickups is caused by low production volume and handmade construction. Using 3D printing lowers the cost of materials and allows for rapid prototyping of different bridge shapes. The bridge will have one piezoelectric sensor for each string and provide some level of acoustic isolation between each string.

## Audio processing unit
The pickup will be connected to a signal processor which takes in the microphone-level signals from each string, performs equalization and other processing, then mixes the four processed string signals into a line-level output which can be used with a pedalboard. This will be done using a microcontroller along with audio interface/codec ICs.

## User interface
The user should have a control panel through which to adjust audio parameters like volume and filter cutoff frequencies for each string. The user should also be able to save and recall preset combinations of audio parameters, so the interface would likely require LED displays and encoders to avoid being physically stateful.

# Criterion for success
The user should be able to control the timbre and volume of each string independently, and save and load at least one preset using the user interface. The device should cost around $400 to be competitive with existing pickups.

Automatic Piano Tuner

Joseph Babbo, Colin Wallace, Riley Woodson

Automatic Piano Tuner

Featured Project

# Automatic Piano Tuner

Team Members:

- Colin Wallace (colinpw2)

- Riley Woodson (rileycw2)

- Joseph Babbo (jbabbo2)

# Problem

Piano tuning is a time-consuming and expensive process. An average piano tuning will cost in the $100 - $200 range and a piano will have to be retuned multiple times to maintain the correct pitch. Due to the strength required to alter the piano pegs it is also something that is difficult for the less physically able to accomplish.

# Solution

We hope to bring piano tuning to the masses by creating an easy to use product which will be able to automatically tune a piano by giving the key as input alongside playing the key to get the pitch differential and automatically turning the piano pegs until they reach the correct note.

# Solution Components

## Subsystem 1 - Motor Assembly

A standard tuning pin requires 8-14 nm of torque to successfully tune. We will thus need to create a motor assembly that is able to produce enough torque to rotate standard tuning pins.

## Subsystem 2 - Frequency Detector/Tuner

The device will use a microphone to gather audio measurements. Then a microprocessor processes the audio data to detect the pitch and determine the difference from the desired frequency. This can then generate instructions for the motor; direction to turn pegs and amount to turn it by.

## Subsystem 3 - User Interface/Display Panel

A small but intuitive display and button configuration can be used for this device. It will be required for the user to set the key being played using buttons on the device and reading the output of the display. As the device will tune by itself after hearing the tone, all that is required to display is the current key and octave. A couple of buttons will suffice to be able to cycle up and down keys and octaves.

## Subsystem 4 - Replaceable Battery/Power Supply

Every commercial product should use standard replaceable batteries, or provide a way for easy charging. As we want to develop a handheld device, so that the device doesn’t have to drag power wires into the piano, we will need a rechargeable battery pack.

# Criterion For Success

The aim of the Automatic Piano Tuner is to allow the user to automatically tune piano strings based on a key input alongside playing a note. We have several goals to help us meet this aim:

- Measure pitch accurately, test against known good pitches

- Motor generates enough torque to turn the pegs on a piano

- Tuner turns correctly depending on pitch

- Easy tuning of a piano by a single untrained person

Project Videos