PyPortal Guitar Tuner - Adafruit Industries · 2020. 10. 28. · Build a simple Guitar Tuner with CircuitPython and Adafruit PyPortal! Use the touch screen to tap on tuning pegs and

PyPortal Guitar TunerCreated by Ruiz Brothers

Last updated on 2021-03-17 01:18:12 PM EDT

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Guide Contents

Guide ContentsOverview

CircuitPython Power!3D Printed PyPortal CaseParts

3D PrintingParts ListCAD AssemblySlicing PartsDesign Source Files

Install CircuitPythonSet up CircuitPython Quick Start!PyPortal Default Files

CircuitPython LibrariesInstalling the CircuitPython Library BundleExample Files

Copying Libraries to Your BoardExample: ImportError Due to Missing LibraryLibrary Install on Non-Express BoardsUpdating CircuitPython Libraries/Examples

Coding the PyPortal Guitar TunerAdding LibrariesCodeAudio Files and Bitmap Graphic

CircuitPython Code WalkthroughSetup

CircuitPython LibrariesDisplay SetupLoading Audio FilesTouchscreen ButtonsButton State

The LoopPlay Notes

AssemblyHardware SetupInstall StandoffsScreen CoverInstall Screen CoverInstalled Screen CoverInstalling Plate and SpeakerConnect SpeakerInstall SpeakerSecure PyPortalInstall FrameSecure FrameFinal BuildGoing Further

© Adafruit Industries https://learn.adafruit.com/pyportal-guitar-tuner Page 2 of 28

Overview

CircuitPython Power!Build a simple Guitar Tuner with CircuitPython and Adafruit

PyPortal! Use the touch screen to tap on tuning pegs and

play music notes. The notes are pre-recorded wav audio files

of guitar strings. The graphic of the head stock is a single

bitmap. This uses the displayio library for CircuitPython and

can be customized to make a unique sound board.

3D Printed PyPortal CaseThe Adafruit PyPortal and a mini oval speaker are secured to

a 3D printed enclosure using M2.5 screws and standoffs. The

PyPortal is mounted vertically and features a built-in holder

for a speaker.

Parts


https://learn.adafruit.com//assets/91821https://learn.adafruit.com//assets/91823https://www.adafruit.com/product/4116https://www.adafruit.com/product/3923https://www.adafruit.com/product/4111https://www.adafruit.com/product/3299

Adafruit PyPortal - CircuitPython Powered Internet Display

PyPortal, our easy-to-use IoT device that allows you to create all the things for the “Internet of Things” in

minutes. Make custom touch screen interface...

Out of Stock

Mini Oval Speaker - 8 Ohm 1 Watt

Hear the good news! This wee speaker is a great addition to any audio project where you need 8 ohm

impedance and 1W or less of power. We particularly like...

$1.95

In Stock

Out ofStock

Add to Cart


https://www.adafruit.com/product/4116https://www.adafruit.com/product/4116https://www.adafruit.com/product/3923https://www.adafruit.com/product/3923

Fully Reversible Pink/Purple USB A to micro B Cable - 1m long

This cable is not only super-fashionable, with a woven pink and purple Blinka-like pattern, it's also fully

reversible! That's right, you will save seconds a day by...

Out of Stock

Out ofStock


https://www.adafruit.com/product/4111https://www.adafruit.com/product/4111

Black Nylon Screw and Stand-off Set – M2.5 Thread

Totaling 380 pieces, this M2.5 Screw Set is a must-have for your workstation. You'll have enough screws,

nuts, and hex standoffs to fuel your maker...

$16.95

In Stock

Add to Cart


https://www.adafruit.com/product/3299https://www.adafruit.com/product/3299

3D Printing

Parts ListSTL files for 3D printing are oriented to print "as-is" on FDM

style machines. Parts are designed to 3D print without any

support material. Original design source may be downloaded

using the links below.

frame.stl

screen-cover.stl

pcb-plate.stl

https://adafru.it/LBu

https://adafru.it/LBv

CAD AssemblyThe PyPortal is secured to the PCB plate using M2.5

hardware screws and standoffs. The screen cover is press

fitted over the PyPortal's display. The PCB plate is secured to

the frame using M2.5 hardware screws and hex nuts. The

speaker is press fitted into the holder in the center of the PCB

plate.

Slicing PartsNo supports are required. Slice with settings for PLA material.

The parts were sliced using CURA using the slice settings

below.

PLA filament 220c extruder

0.2 layer height

10% gyroid infill

60mm/s print speed

60c heated bed

https://adafru.it/LBu

https://adafru.it/LBv


https://learn.adafruit.com//assets/91798https://a360.co/2XHthEYhttps://www.thingiverse.com/thing:4438992https://learn.adafruit.com//assets/91813https://learn.adafruit.com//assets/91815

Design Source FilesThe project assembly was designed in Fusion 360. This can

be downloaded in different formats like STEP, STL and more.

Electronic components like Adafruit's board, displays,

connectors and more can be downloaded from the Adafruit

CAD parts GitHub Repo (https://adafru.it/AW8).


https://learn.adafruit.com//assets/91816https://github.com/adafruit/Adafruit_CAD_Parts

Install CircuitPythonCircuitPython (https://adafru.it/tB7) is a derivative of MicroPython (https://adafru.it/BeZ) designed to

simplify experimentation and education on low-cost microcontrollers. It makes it easier than ever to get

prototyping by requiring no upfront desktop software downloads. Simply copy and edit files on the

CIRCUITPY "flash" drive to iterate.

The following instructions will show you how to install CircuitPython. If you've already installed

CircuitPython but are looking to update it or reinstall it, the same steps work for that as well!

Set up CircuitPython Quick Start!Follow this quick step-by-step for super-fast Python power :)

https://adafru.it/Egk

https://adafru.it/HFd

Click the link above to download the latest version of

CircuitPython for the PyPortal.

Download and save it to your desktop (or wherever is handy).

Plug your PyPortal into your computer using a known-good

USB cable.

A lot of people end up using charge-only USB cables and it

is very frustrating! So make sure you have a USB cable you

know is good for data sync.

Double-click the Reset button on the top in the middle

(magenta arrow) on your board, and you will see the NeoPixel

RGB LED (green arrow) turn green. If it turns red, check the

USB cable, try another USB port, etc. Note: The little red LED

next to the USB connector will pulse red. That's ok!

If double-clicking doesn't work the first time, try again.

Sometimes it can take a few tries to get the rhythm right!

https://adafru.it/Egk

https://adafru.it/HFd


https://github.com/adafruit/circuitpythonhttps://micropython.orghttps://circuitpython.org/board/pyportal/https://circuitpython.org/board/pyportal_pynt/https://learn.adafruit.com//assets/73615https://learn.adafruit.com//assets/71993

You will see a new disk drive appear called PORTALBOOT.

Drag the adafruit-circuitpython-pyportal-.uf2 file

to PORTALBOOT.

The LED will flash. Then, the PORTALBOOT drive will

disappear and a new disk drive called CIRCUITPY will

appear.

If you haven't added any code to your board, the only file that

will be present is boot_out.txt. This is absolutely normal! It's

time for you to add your code.py and get started!

That's it, you're done! :)

PyPortal Default FilesClick below to download a zip of the files that shipped on the PyPortal or PyPortal Pynt.

https://adafru.it/Env

https://adafru.it/HFf

https://adafru.it/Env

https://adafru.it/HFf


https://learn.adafruit.com//assets/72029https://learn.adafruit.com//assets/72030https://learn.adafruit.com//assets/71995https://github.com/adafruit/circuitpython-default-files/tree/master/boards/pyportal/4.xhttps://github.com/adafruit/circuitpython-default-files/tree/master/boards/pyportal_pynt/5.x

CircuitPython Libraries� As we continue to develop CircuitPython and create new releases, we will stop supporting olderreleases. Visit https://circuitpython.org/downloads to download the latest version of CircuitPython for

your board. You must download the CircuitPython Library Bundle that matches your version of

CircuitPython. Please update CircuitPython and then visit https://circuitpython.org/libraries to

download the latest Library Bundle.

Each CircuitPython program you run needs to have a lot of information to work. The reason CircuitPython

is so simple to use is that most of that information is stored in other files and works in the background.

These files are called libraries. Some of them are built into CircuitPython. Others are stored on yourCIRCUITPY drive in a folder called lib. Part of what makes CircuitPython so awesome is its ability to store

code separately from the firmware itself. Storing code separately from the firmware makes it easier to

update both the code you write and the libraries you depend.

Your board may ship with a lib folder already, it's in the base directory of the drive. If not, simply create the

folder yourself. When you first install CircuitPython, an empty lib directory will be created for you.

CircuitPython libraries work in the same way as regular Python modules so the Python

docs (https://adafru.it/rar) are a great reference for how it all should work. In Python terms, we can place

our library files in the lib directory because its part of the Python path by default.

One downside of this approach of separate libraries is that they are not built in. To use them, one needs

to copy them to the CIRCUITPY drive before they can be used. Fortunately, we provide a bundle full of

our libraries.

Our bundle and releases also feature optimized versions of the libraries with the .mpy file extension.

These files take less space on the drive and have a smaller memory footprint as they are loaded.


https://circuitpython.org/downloadshttps://circuitpython.org/librarieshttps://docs.python.org/3/tutorial/modules.html

Installing the CircuitPython Library BundleWe're constantly updating and improving our libraries, so we don't (at this time) ship our CircuitPython

boards with the full library bundle. Instead, you can find example code in the guides for your board that

depends on external libraries. Some of these libraries may be available from us at Adafruit, some may be

written by community members!

Either way, as you start to explore CircuitPython, you'll want to know how to get libraries on board.

You can grab the latest Adafruit CircuitPython Bundle release by clicking the button below.

Note: Match up the bundle version with the version of CircuitPython you are running - 3.x library for

running any version of CircuitPython 3, 4.x for running any version of CircuitPython 4, etc. If you mix

libraries with major CircuitPython versions, you will most likely get errors due to changes in library

interfaces possible during major version changes.

https://adafru.it/ENC

If you need another version, you can also visit the bundle release page (https://adafru.it/Ayy) which will let

you select exactly what version you're looking for, as well as information about changes.

Either way, download the version that matches your CircuitPython firmware version. If you don't know

the version, look at the initial prompt in the CircuitPython REPL, which reports the version. For example, if

you're running v4.0.1, download the 4.x library bundle. There's also a py bundle which contains the

uncompressed python files, you probably don't want that unless you are doing advanced work onlibraries.

After downloading the zip, extract its contents. This is usually done by double clicking on the zip. On Mac

OSX, it places the file in the same directory as the zip.

Open the bundle folder. Inside you'll find two information files, and two folders. One folder is the lib

bundle, and the other folder is the examples bundle.

https://adafru.it/ENC


https://circuitpython.org/librarieshttps://github.com/adafruit/Adafruit_CircuitPython_Bundle/releases/latest/

Now open the lib folder. When you open the folder, you'll see a large number of mpy files and folders

Example FilesAll example files from each library are now included in the bundles, as well as an examples-only bundle.

These are included for two main reasons:

Allow for quick testing of devices.

Provide an example base of code, that is easily built upon for individualized purposes.

Copying Libraries to Your BoardFirst you'll want to create a lib folder on your CIRCUITPY drive. Open the drive, right click, choose the

option to create a new folder, and call it lib. Then, open the lib folder you extracted from the downloaded

zip. Inside you'll find a number of folders and .mpy files. Find the library you'd like to use, and copy it to

the lib folder on CIRCUITPY.

This also applies to example files. They are only supplied as raw .py files, so they may need to be

converted to .mpy using the mpy-cross utility if you encounter MemoryErrors . This is discussed in theCircuitPython Essentials Guide (https://adafru.it/CTw). Usage is the same as described above in the


https://learn.adafruit.com/circuitpython-essentials/circuitpython-expectations#how-can-i-create-my-own-mpy-files-18-6

Express Boards section. Note: If you do not place examples in a separate folder, you would remove the

examples from the import statement.

� If a library has multiple .mpy files contained in a folder, be sure to copy the entire folder toCIRCUITPY/lib.

Example: ImportError Due to Missing LibraryIf you choose to load libraries as you need them, you may write up code that tries to use a library you

haven't yet loaded. We're going to demonstrate what happens when you try to utilise a library that you

don't have loaded on your board, and cover the steps required to resolve the issue.

This demonstration will only return an error if you do not have the required library loaded into the lib

folder on your CIRCUITPY drive.

Let's use a modified version of the blinky example.

import boardimport timeimport simpleio

led = simpleio.DigitalOut(board.D13)

while True: led.value = True time.sleep(0.5) led.value = False time.sleep(0.5)

Save this file. Nothing happens to your board. Let's check the serial console to see what's going on.

We have an ImportError . It says there is no module named 'simpleio' . That's the one we just included in ourcode!

Click the link above to download the correct bundle. Extract the lib folder from the downloaded bundle

file. Scroll down to find simpleio.mpy. This is the library file we're looking for! Follow the steps above to

load an individual library file.

The LED starts blinking again! Let's check the serial console.


No errors! Excellent. You've successfully resolved an ImportError !

If you run into this error in the future, follow along with the steps above and choose the library that

matches the one you're missing.

Library Install on Non-Express BoardsIf you have a Trinket M0 or Gemma M0, you'll want to follow the same steps in the example above to

install libraries as you need them. You don't always need to wait for an ImportError as you probably knowwhat library you added to your code. Simply open the lib folder you downloaded, find the library you

need, and drag it to the lib folder on your CIRCUITPY drive.

You may end up running out of space on your Trinket M0 or Gemma M0 even if you only load libraries as

you need them. There are a number of steps you can use to try to resolve this issue. You'll find them in

the Troubleshooting page in the Learn guides for your board.

Updating CircuitPython Libraries/ExamplesLibraries and examples are updated from time to time, and it's important to update the files you have on

your CIRCUITPY drive.

To update a single library or example, follow the same steps above. When you drag the library file to your

lib folder, it will ask if you want to replace it. Say yes. That's it!

A new library bundle is released every time there's an update to a library. Updates include things like bug

fixes and new features. It's important to check in every so often to see if the libraries you're using have

been updated.


Coding the PyPortal Guitar TunerAdding LibrariesOnce you've finished setting up your PyPortal with CircuitPython, you can add these libraries to

the lib folder:

adafruit_bitmap_font

adafruit_bus_device

adafruit_display_shapes

adafruit_display_text

adafruit_esp32spi

adafruit_imageload

adafruit_io

adafruit_adt7410.mpy

adafruit_button.mpy

adafruit_pyportal.mpy

adafruit_requests.mpy

adafruit_sdcard.mpy

adafruit_touchscreen.mpy

neopixel.mpy

Then, you can click on the Download: Project Zip link above the code to download the code file, audio

files and bitmap file.

CodeClick on "Copy Code" and then paste it into the Mu editor to save to your PyPortal as code.py or copy the

code file from the Project Zip folder to the PyPortal's CIRCUITPY drive.

You will also need the secrets.py code file from the Project Zip folder since it is required for the PyPortal

CircuitPython library.


import timefrom adafruit_button import Buttonfrom adafruit_pyportal import PyPortal

pyportal = PyPortal(default_bg="/stock-pyportal.bmp")

lowE = "/sounds/lowE.wav"A = "/sounds/A.wav"D = "/sounds/D.wav"G = "/sounds/G.wav"B = "/sounds/B.wav"highE = "/sounds/highE.wav"

notes = [lowE, A, D, G, B, highE]

pegs = [ {'label': "lowE", 'pos': (53, 0), 'size': (65, 90)}, {'label': "A", 'pos': (124, 0), 'size': (65, 90)}, {'label': "D", 'pos': (194, 0), 'size': (65, 90)}, {'label': "G", 'pos': (194, 150), 'size': (65, 90)}, {'label': "B", 'pos': (124, 150), 'size': (65, 90)}, {'label': "highE", 'pos': (53, 150), 'size': (65, 90)} ]

buttons = []for peg in pegs: button = Button(x=peg['pos'][0], y=peg['pos'][1], width=peg['size'][0], height=peg['size'][1], style=Button.RECT, fill_color=None, outline_color=0x5C3C15, name=peg['label']) pyportal.splash.append(button.group) buttons.append(button)

note_select = None

while True: touch = pyportal.touchscreen.touch_point if not touch and note_select: note_select = False if touch: for i in range(6): tuning = notes[i] button = buttons[i] if button.contains(touch) and not note_select: print("Touched", button.name) note_select = True for z in range(3): pyportal.play_file(tuning) time.sleep(0.1)

Audio Files and Bitmap GraphicIn addition to the lib folder, for this project you'll also have a sounds folder. The sounds folder contains

the six audio files that are used to tune your guitar using the PyPortal. Each audio file is a quick sample of

each string on a guitar in standard tuning (E - A - D - G - B - E).

A.wav

B.wav

D.wav


G.wav

highE.wav

lowE.wav

There is also a bitmap image for the PyPortal's display that depicts a guitar's headstock. This image file,

called stock-pyportal.bmp, will also be stored on the PyPortal.

Copy the sounds folder and the stock-pyportal.bmp bitmap image file from the Project Zip folder to the

PyPortal's CIRCUITPY drive.

Your PyPortal CIRCUITPY drive should look like this after you load the libraries, audio files, bitmap and

code files below:


CircuitPython Code WalkthroughSetupCircuitPython LibrariesThe CircuitPython code begins by importing the libraries.

import timefrom adafruit_button import Buttonfrom adafruit_pyportal import PyPortal

Display SetupFirst, pyportal is setup as a PyPortal object. The PyPortal's default background is also setup to be theguitar headstock image, stock-pyportal.bmp. This means that on boot, the PyPortal will display the bitmap

with just one line of code.

pyportal = PyPortal(default_bg="/stock-pyportal.bmp")

Loading Audio FilesThe audio file locations are assigned to variables so that they can be easily referenced in the code. Then,

files are put into the notes array in order from low to high.

lowE = "/sounds/lowE.wav"A = "/sounds/A.wav"D = "/sounds/D.wav"G = "/sounds/G.wav"B = "/sounds/B.wav"highE = "/sounds/highE.wav"

notes = [lowE, A, D, G, B, highE]

Touchscreen ButtonsThe PyPortal will have six buttons that sit on top of the guitar headstock image. Instead of setting each

button up individually, their parameters are setup as a group in an array, called pegs , of dictionaryentries. This way you can easily denote the buttons' label, position and size.

pegs = [ {'label': "lowE", 'pos': (53, 0), 'size': (65, 90)}, {'label': "A", 'pos': (124, 0), 'size': (65, 90)}, {'label': "D", 'pos': (194, 0), 'size': (65, 90)}, {'label': "G", 'pos': (194, 150), 'size': (65, 90)}, {'label': "B", 'pos': (124, 150), 'size': (65, 90)}, {'label': "highE", 'pos': (53, 150), 'size': (65, 90)} ]

Finally, this information for the buttons are assigned as Button objects using the adafruit_buttonCircuitPython library. Using the pegs array, all of the information from the dictionaries can be pulled in tocomplete the setup for the buttons. These buttons are then added to the PyPortal's display.


buttons = []for peg in pegs: button = Button(x=peg['pos'][0], y=peg['pos'][1], width=peg['size'][0], height=peg['size'][1], style=Button.RECT, fill_color=None, outline_color=0x5C3C15, name=peg['label']) pyportal.splash.append(button.group) buttons.append(button)

Button StateThe note_select state will be used to debounce the touchscreen buttons.

note_select = None

The LoopThe loop begins with touch setup to hold the PyPortal's touchscreen functionality.

Next, touchscreen button debouncing is setup. You only need to setup one instance rather than one for

each individual button because you are essentially checking to see if the touchscreen is being touched in

any location.

while True: touch = pyportal.touchscreen.touch_point if not touch and note_select: note_select = False

Play NotesThe final portion of the loop is how notes are played through the PyPortal. First, it checks to see if the

touchscreen has been touched.

This is followed by a for statement. In this for statement, tuning and button are setup to hold the arrayindex locations for the notes and buttons arrays. Since there are six indexes in each of these arrays, thisallows for the sound files to match up with the touchscreen buttons and play when pressed.

Finally, an if statement checks if the touchscreen was touched in the proximity of the coordinates of oneof the button locations. If it was, then the name of the button is printed to the REPL. This is followed by a

final for statement. This for statement allows for the corresponding note's audio file to play three times.

This is followed by a delay. The length of the delay will determine the amount of time between each time

the audio files are played. You may want to adjust it depending on your guitar tuning preferences.

if touch: for i in range(6): tuning = notes[i] button = buttons[i] if button.contains(touch) and not note_select: print("Touched", button.name) note_select = True for z in range(3): pyportal.play_file(tuning) time.sleep(0.1)


Assembly

Hardware SetupUse 4x M2.5 x 6mm long FF standoffs and 4x M2.5 x 6mm

long screws to secure the PCB plate to the PyPortal.

Install StandoffsInsert M2.5 x 6mm screws through the top of the mounting

tabs on PyPortal. Fasten M2.5 x 6mm long standoffs onto the

threads of the screws.

Screen CoverOrient the screen cover with the display on the PyPortal. Use

the photo to reference the correct orientation.


https://learn.adafruit.com//assets/91799https://learn.adafruit.com//assets/91800https://learn.adafruit.com//assets/91801

Install Screen CoverFit the PyPortal display into the recess on the screen cover.

Press the screen to fully seat into the screen cover.

Installed Screen CoverThe screen cover helps to keep the display attached to the

PyPortal. The viewing area is exposed and does not obstruct

display. This also hides the screens bezel.

Installing Plate and SpeakerThe PyPortal is secured to the PCB plate using 4x M2.5 x

6mm screws. The mini oval speaker is press fitted onto the

speaker holder on the PCB plate.

Connect SpeakerPlug in the molex pico connector from the speaker to the

speaker port on the back of the PyPortal.


https://learn.adafruit.com//assets/91802https://learn.adafruit.com//assets/91803https://learn.adafruit.com//assets/91804https://learn.adafruit.com//assets/91806

Install SpeakerPress fit the body of the speaker into the speaker holder in

the center of the PCB plate. Reference the photo for best

orientation.

Secure PyPortalPlace the PCB plate to the back of the PyPortal with the

mounting holes lined up with the standoffs.

Install FrameOrient the frame with the mount tabs on the PCB plate. Line

up the mounting holes in the frame with the mounting tabs on

the PCB.

Secure FrameInsert 4x M2.5 x 6mm screws into the side of the frame and

through the mounting tabs on the PCB plate. Insert and

fasten 4x M2.5 hex nuts onto threads of the screws and

tighten.


https://learn.adafruit.com//assets/91805https://learn.adafruit.com//assets/91807https://learn.adafruit.com//assets/91808https://learn.adafruit.com//assets/91809

Final BuildAnd now we're ready for some guitar tuning!

Going FurtherThe frame has adequate amount of space for a USB battery

or other components.


https://learn.adafruit.com//assets/91810https://learn.adafruit.com//assets/91811

© Adafruit Industries Last Updated: 2021-03-17 01:18:12 PM EDT Page 28 of 28

Guide ContentsOverviewCircuitPython Power!3D Printed PyPortal CaseParts

3D PrintingParts ListCAD AssemblySlicing PartsDesign Source Files

Install CircuitPythonSet up CircuitPython Quick Start!PyPortal Default Files

CircuitPython LibrariesInstalling the CircuitPython Library BundleExample Files

Copying Libraries to Your BoardExample: ImportError Due to Missing LibraryLibrary Install on Non-Express BoardsUpdating CircuitPython Libraries/Examples

Coding the PyPortal Guitar TunerAdding LibrariesCodeAudio Files and Bitmap Graphic

CircuitPython Code WalkthroughSetupCircuitPython LibrariesDisplay SetupLoading Audio FilesTouchscreen ButtonsButton State

The LoopPlay Notes

AssemblyHardware SetupInstall StandoffsScreen CoverInstall Screen CoverInstalled Screen CoverInstalling Plate and SpeakerConnect SpeakerInstall SpeakerSecure PyPortalInstall FrameSecure FrameFinal BuildGoing Further

Documents

PyPortal Guitar Tuner - Adafruit Industries · 2020. 10. 28. · Build a simple Guitar Tuner with CircuitPython and Adafruit PyPortal! Use the touch screen to tap on tuning pegs and