Introduction: GuitarBot

The GuitarBot started as the collaborative work of three University of Delaware professors: Dustyn Roberts, Troy Richards, and Ashley Pigford. The project has been worked on by teams of their students since Spring 2015 and has been passed along since. The work is part of an initiative at the University of Delaware dubbed 'Artgineering,' a portmanteau of the terms Art and Engineering. As its name suggests, the initiative is designed to facilitate greater collaboration between art and engineering. The GuitarBot itself was intended to create a public spectacle in hopes to demonstrate that engineering and art can work together harmoniously. Being a part of the larger “Maker” community ensures that this project is constantly growing and adapting with all those that use it. The authors are students working under the guidance of the University of Delaware and the College of Engineering Summer Fellows Program 2017. Our goal for this program is to provide the GuitarBot to use as an educational platform by providing the code and simple documentation on how we created our Guitarbot.

GuitarBot is, as the name implies, a guitar-playing robot that has three major components: the brains, strummer, and chord mechanism. The brains, comprised of an Arduino® Mega, specially-ordered PCB board, and several shields, serve to control the system. The strummer is essentially a pick that is pulled by a direct current motor with encoder attached to a belt. The chord mechanism is a series of solenoids that press down certain frets. The GuitarBot is a multi-faceted entry level technology that contains smaller, team-oriented projects that unite. All who make it will get to dive into....

  • Microcontrollers
  • Shields
  • Micro SD
  • Solenoids
  • T-slotted aluminum (80/20®)
  • Printed circuit board (using/ordering)
  • Direct current motor with encoder
  • 3D printing
  • Basic woodworking
  • Laser cutting

Step 1: Bill of Materials

The GuitarBot is a large project. As a result, there are two different bills of materials. Each item includes a unit price as well as a purchasing link to simplify the purchasing process.

The first is split into building section. This is designed to let you gather all of the materials you will need for each section before even starting it.

The second is designed to simplify purchasing. We've done this by splitting the list into retailer sections. This means that if you are planning on building the entire GuitarBot, part for part according to these instructions this would be the place to start.

Step 2: Tools

Throughout this project, you will use a multitude of tools. This list contains each of the tools you will need as well as what section you will be using these tools in. Additionally, the links below will help ensure that you use these tools properly and safely.

Hacksaw with Aluminum:

Soldering Iron:



Step 3: Ordering PCB

To buy our PCB, we went here, using the two layer option. We uploaded the file when prompted. When asked for specifics, we said X dimension is 7.65 inches, Y dimension is 4.24 inches, the soldermask should be on both sides, the silkscreen should be on the top side, there should be two layers, and 3 boards.

Step 4: CAD Parts

Although the majority of the GuitarBot can be purchased, some parts need to be 3D printed. These parts are designed to be small enough to fit in most home printers (10" x 6" x 6").

Pick Holder:

This component is used in the Strumming Assembly to hold the pick in place relative to the shafts and belt.

Step 5: Strummer

The first part of the GuitarBot that we will build is the Strumming Assembly. This is the aspect of the robot that will control the pick while helping hold the structure together. This section is split up into three distinct parts that should be completed in order.

5.1 Motor Side:

This part of the Strummer houses the DC motor with an encoder which is used to control the position of the pick, allowing the robot to strum.

5.2 Pulley Side:

A timing belt would not be complete without two sides. This aspect of the Strummer contains the pulley that ensures the driving belt is kept taught so it does not skip while in use.

5.3 Assembly:

Once these two components are built, all that's left is assembly. In this section you will assemble the separate components of the Strummer into one cohesive structure.

Step 6: Structure

Now that you have built the Strumming component of the GuitarBot, the next thing to do is to build the frame. The overall structure of the GuitarBot is what's going to hold everything together, from the Strummer and the Brains, to the guitar itself. The Structure is split into five components that should be completed in order.

6.1 Cutting:

Before you can start putting the Structure together, you will first have to cut up the t-slotted aluminum.

6.2 Legs:

Now that you have the t-slotted aluminum in a bunch of usable sizes, it is time to start assembling. First are the legs. This section is the support of the GuitarBot. Additionally, it will hold the power supplies for the motor and the solenoids.

6.3 Arms:

Next are the so called 'Arms'. These components connect the legs together and, more importantly, hold the guitar in place.

6.4 Assembly:

Now that both the Arms and the Legs are built the next step is to put it all together. Additionally, you will also attach the Strumming component to the rest of the frame here.

6.5 Foam:

Before we add the guitar onto the frame we want to make sure that it will not be damaged from the metal of the frame. This is accomplished by adding foam to the areas that contact the guitar.

Step 7: Brains

With all of the framework in place for your new GuitarBot it is time to attach the system that will control your Strumming component and ultimately all of your robot. We have combined all of this into the 'Brains" section where you will build and wire all of the circuitry needed for this project.

In this section you will learn how to solder. If you don’t know how to solder, you can read about it here:

Soldering is an imperfect process, but luckily your mistakes are not permanent. If you make a mistake you can always de-solder (we recommend using a pump). You can read about it here:

7.1 Screw Shield:

Since you will be attaching a lot of wires to the microcontroller of this robot, we are going to want a more secure way to attach wires. The screw shield you assemble in this section will be the top shield on the Mega that lets you easily and securely create connections.

7.2 Motor Shield:

Just below the screw shield lies the motor shield. This shield is designed to connect to and control the DC motor installed early for the Strumming component. Just like the screw shield, this board still needs headers and screw terminals soldered onto it.

7.3 PCB Soldering:

The last component that needs to be soldered together is the Printed Custom Board. The GuitarBot is able to make chords by controlling a 5 x 6 matrix of solenoids, however the Mega cannot output enough power to operate these solenoids. Instead, it will allow power to pass from the 24v power supply to operate these parts. The PCB will house the integrated circuit chips that allow the Mega to control this flow of power.

7.4 Assembly:

Once you've assembled all the brains parts before this step, you can drill the PCB, screw the Mega to it, stack the shields on the Mega, and attach the brains to the frame.

7.5 Wiring:

Now that the brains are assembled, we have to put them to work by wiring them up to the power supplies, motor, and solenoids.

7.6 Button:

After finishing the wiring you should still have some loose ends, so naturally we want to tie those up. Those wires belong to the button that will allow the GuitarBot to play a song again after it has finished.

Step 8: Bonus: Fret WIP

These next few sections are for the aspects of the GuitarBot that are currently under development. These instructions do not represent the final state the GuitarBot will take, but they do add new features and functionality to the robot. The materials used in these instructions are not accounted for the in the general Bill of Materials presented earlier, but each work in progress includes its own bill of materials as well as a tool list.

So now your robot still needs something to make chords. These instructions and files will enable you to construct the current iteration of the fret assembly for the GuitarBot.

Step 9: Bonus: Fret WIP Code

Even though your GuitarBot seems complete, it will not do anything until you upload the appropriate code. If you are using the old fret assembly the code here follows that matrix and comes pre-loaded with the chords from "This Land Is Your Land" by Woody Guthrie.

In order to use the code, download the Arduino application from for your computer. Then download this '.ino' file. Attach the Arduino board to your computer using the usb hookup. Search for the line that says "Must write to SD card and then comment out to actually play song." Uncomment the following two lines, upload the file to the Arduino, then your GuitarBot should play! After this instance, you may comment out the lines that write to the SD card.