| Name | NetID | Section |
|---|---|---|
| Manit Niwas | mniwas2 | ECE 120 |
| Sean Ramirez | srami20 | ECE 110 |
Statement of Purpose
Our goal is to build and program a device that automatically plays pre-programmed songs on an acoustic guitar. Our “Auto Guitar” will accomplish this with a combination of servos on the fretboard, specifically frets 1, 2, and 3, as well as servos playing the strings of the guitar to automatically play music on the instrument. This device serves as a reference utility for the pre-programmed songs and can be used when a pure form of sound is desired over a digitized version.
Background Research
When we first thought of the idea, one of our initial thoughts was wondering which kind of guitar to use. From prior experience with guitars, we decided to use an acoustic guitar because of the additional space it has on its fretboard compared to other types of guitars. Having more space would make the mechanical design of our idea easier to implement. This led our train of thought to the kinds of components we want to use. We decided that servos would better fit the cost and size constraints than motors. After researching parts, we moved on to thinking about the actual mechanism. We explored the ideas of pistons, bars, and gear chains, but eventually, we decided to pair each servo on the fretboard with 2 strings and use a curved arm attached to the servos to push down on the string. This idea is also superior to the others because, after researching different chord shapes, we realized that it allows us to play a wider variety of notes in an efficient way. To mimic the feeling of a finger on a string, we are thinking of using rubber as the material to make contact with the strings while fretting in order to produce the best sound possible. By this point, we realized that this idea was something feasible, so we decided to pursue it further.
We looked at similar ideas, and students at Purdue University had done something very similar to what we were thinking. The mechanism for fretting the strings was by using pistons, so our idea differs from theirs here. We are also only fretting 3 frets, whereas they chose to fret 4. Our picking mechanism is similar to theirs, however, we are choosing to use picks instead of plastic like they did.
Block Diagram / Flow Chart and System Overview
Parts
Acoustic Guitar - Already in Possession.
11 Micro Servos from Adafruit, Product ID: 169, $5.95 each.
4 Servos - Generic High Torque (Standard Size) from SparkFun, ROB-11965, In Stock at ECEB.
Raspberry Pi 4 (8 GB) - Already in Possession.
3D printed mounts for the servos.
Adafruit 16-Channel PWM / Servo Bonnet for Raspberry Pi, Product ID: 3416, $9.95.
Possible Challenges
One possible challenge we need to address is how we will mount the servos in such a way that their arms to push down on the string don’t interfere with each other. For example. If two servos need to push down on two strings next to each other, they must do so in a way that the arms attached to each servo don’t hit each other. Another challenge we might face is having enough room on the fretboard for all the servos we want to use along with each one of their mechanisms. Additionally, we also need to see if the servos can apply enough pressure to pluck and fret the strings properly.
Evaluation
Final Paper: https://docs.google.com/document/d/1V4IXuGBSOwsf8mnmikOuFG1tM8HPQPJvdz_y8M6bdNY/edit?usp=sharing
Final Video: https://drive.google.com/file/d/1RWaQh_LEoTUuEDx5EmG2JhZ-iQQCNnQa/view?usp=sharing
References
Posted by as85 at Sep 24, 2021 18:21