Adafruit Language Flashcards on the MagTag User Manual

Language Flashcards on the MagTag

Created by Lucian Copeland

Last updated on 2021-04-15 08:19:06 PM EDT

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Guide Contents

Guide Contents Overview

Parts

Install CircuitPython

Set Up CircuitPython

Option 1 - Load with UF2 Bootloader

Try Launching UF2 Bootloader

Option 2 - Use esptool to load BIN file Option 3 - Use Chrome Browser To Upload BIN file CircuitPython Internet Libraries

Adafruit CircuitPython Library Bundle

CircuitPython Internet Test

Secrets File Connect to WiFi

Getting The Date & Time

Step 1) Make an Adafruit account Step 2) Sign into Adafruit IO Step 3) Get your Adafruit IO Key Step 4) Upload Test Python Code

MagTag-Specific CircuitPython Libraries

Get Latest Adafruit CircuitPython Bundle Secrets

Simple Flashcards

Download the Software Example Deck How does it work?

Complicated Flashcards

Download the Software New Deck Format Program Flow Code Walkthrough

Setup: Chapter Selection: Flashcard Session: Wrapping up:

Other Resources

Font License:

Overview

When you’re studying something that needs a lot of memorization, like learning a language, prepping for a tough biology exam, or mastering all those pesky built-in Python functions, it’s hard to beat a good old deck of flashcards. It’s the tried and true method of getting tough subjects to stick to your grey matter especially when you’re on a deadline, and you’ve really got to get this stuff

down

or you are going to

flunk

most heinously tomorrow, dude!

But like many old fashioned methods, flashcards can be kind of a pain! You have to spend ages writing them all out on paper, and then somebody knocks them off the table and one goes under the fridge, and then your buddy asks to borrow them but you’re not

finished

and you’re not going to make him a

whole

other deck,

are you

kidding,

and now the edges have gotten all bent so they don’t shuffle well any more, and then once you’ve finally gotten everything memorized there’s nothing to do but toss them all out and get started on the next deck. The results may be good, but the process? Frustrating.

Enter the MagTag!

With CircuitPython, you can type out your flashcards in JSON, and you’ll never be stuck writing and shuffling huge decks of index cards again. You can sort them by chapters, support lots of different international fonts, even share them with your slacker buddy with a simple copy-paste. Maybe not the

most

old-fashioned anymore, but it’s e-paper, so we’re pretty sure it still counts.

Thanks to Unicode font support in CircuitPython, you can quickly and easily make text for

any language

using free fonts!

 This guide uses the e-paper and other hardware features of the MagTag, but note that it does not

use any of the ESP32-S2 networking capabilities (WIFI, etc). Setting up WIFI is included in the installation process for completeness, but the final project will not connect to the internet, so you can skip those steps if you want! Just install Circuitpython and the libraries, and don't worry about secrets.py or the internet tests. If you'd specifically like to do a connected IoT project, we've got lots of other guides to do that - check out the full list Magtag tutorials for ideas!

Parts

The MagTag starter kit comes with a battery and some magnets included. You'll also need to grab a USB C cable separately, if you don't have one:

Adafruit MagTag Starter Kit - 2.9" Grayscale E-Ink WiFi Display

The Adafruit MagTag combines the new ESP32-S2 wireless module and a 2.9" grayscale E-Ink display to make a low-power IoT display that can show data on its screen... Out of Stock

Out of

Stock

USB Type A to Type C Cable - approx 1 meter / 3 ft long

As technology changes and adapts, so does Adafruit. This USB Type A to Type C cable will help you with the transition to USB C, even if you're still... $4.95 In Stock

Alternatively, you can get the parts individually, if you'd like to swap out the battery or omit the magnets.

Add to Cart

Adafruit MagTag - 2.9" Grayscale E-Ink WiFi Display

The Adafruit MagTag combines the new ESP32-S2 wireless module and a 2.9" grayscale E-Ink display to make a low-power IoT display that can show data on its screen even when power... Out of Stock

Out of

Stock

Lithium Ion Polymer Battery with Short Cable - 3.7V 420mAh

Lithium ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light and powerful. The output ranges from 4.2V when completely charged to 3.7V. This battery... $6.95 In Stock

Mini Magnet Feet for RGB LED Matrices (Pack of 4)

Got a glorious RGB Matrix project you want to mount and display in your workspace or home? If you have one of the matrix panels listed below, you'll need a pack of these... $2.50 In Stock

Add to Cart

Install CircuitPython

CircuitPython (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 drive to iterate.

Set Up CircuitPython

Follow the steps to get CircuitPython installed on your MagTag.

https://adafru.it/OBd

Click the link above and download the latest .BIN and .UF2

file

(depending on how you program the ESP32S2 board you may need one or the other, might as well get both)

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

Plug your MagTag 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.

https://adafru.it/OBd

Option 1 - Load with UF2 Bootloader

This is by far the easiest way to load CircuitPython. However it requires your board has the UF2

bootloader installed. Some early boards do not (we hadn't written UF2 yet!) - in which case you can load

using the built in ROM bootloader.

Still, try this first!

Try Launching UF2 Bootloader

Loading CircuitPython by drag-n-drop UF2 bootloader is the easier way and we recommend it. If you have a MagTag where the front of the board is black, your MagTag came with UF2 already on it.

Launch UF2 by double-clicking the Reset button (the one next to the USB C port). You may have to try a few times to get the timing right.

If the UF2 bootloader is installed, you will see a new disk drive appear called MAGTAGBOOT

Copy the UF2 file you downloaded at the first step of this tutorial onto the MAGTAGBOOT drive

If you're using Windows and you get an error at the end of the file copy that says Error from the file copy, Error 0x800701B1: A device which does not exist was specified. You can ignore this error, the bootloader sometimes disconnects without telling Windows, the install completed just fine and you can continue. If its

really annoying, you can also upgrade the bootloader (the latest version of the UF2 bootloader fixes this warning) (https://adafru.it/Pfk)

Your board should auto-reset into CircuitPython, or you may need to press reset. A CIRCUITPY drive will appear. You're done! Go to the next pages.

Option 2 - Use esptool to load BIN file

If you have an original MagTag with while soldermask on the front, we didn't have UF2 written for the ESP32S2 yet so it will not come with the UF2 bootloader.

You can upload with esptool to the ROM (hardware) bootloader instead!

Follow the initial steps found in the Run esptool and check

connection section of the ROM Bootloader page (https://adafru.it/OBc) to verify your environment is set

up, your board is successfully connected, and which port it's using.

In the final command to write a binary file to the board,

replace the port with your port, and replace "firmware.bin"

with the the file you downloaded above.

The output should look something like the output in the image.

Press reset to exit the bootloader.

Your CIRCUITPY drive should appear!

You're all set! Go to the next pages.

Option 3 - Use Chrome Browser To Upload BIN file

If for some reason you cannot get esptool to run, you can always try using the Chrome-browser version of esptool we have written. This is handy if you don't have Python on your computer, or something is really weird with your setup that makes esptool not run (which happens sometimes and isn't worth debugging!) You can follow along on the Web Serial ESPTool (https://adafru.it/Pdq) page and either load the UF2 bootloader and then come back to Option 1 on this page, or you can download the CircuitPython BIN file directly using the tool in the same manner as the bootloader.

CircuitPython Internet Libraries

To use the internet-connectivity built into your ESP32-S2 with CircuitPython, you must first install a number of libraries. This page covers that process.

Adafruit CircuitPython Library Bundle

Download the Adafruit CircuitPython Bundle. You can find the latest release here:

https://adafru.it/ENC

Download the adafruit-circuitpython-bundle-version-mpy-*.zip bundle zip file, and unzip a folder of the same name. Inside you'll find a lib folder. The entire collection of libraries is too large to fit on the CIRCUITPY drive. Instead, add each library as you need it, this will reduce the space usage but you'll need to put in a little more effort.

At a minimum we recommend the following libraries, in fact we more than recommend. They're basically required. So grab them and install them into CIRCUITPY/lib now!

adafruit_requests.mpy - A requests-like library for HTTP commands. neopixel.mpy - Helper library to use NeoPixel LEDs, often built into the boards so they're great for

quick feedback

Once you have added those files, please continue to the next page to set up and test Internet connectivity

https://adafru.it/ENC

CircuitPython Internet Test

Once you have CircuitPython installed and the minimum libraries installed we can get your board connected to the Internet.

To get connected, you will need to start by creating a secrets.py file.

Secrets File

We expect people to share tons of projects as they build CircuitPython WiFi widgets. What we want to avoid is people accidentally sharing their passwords or secret tokens and API keys. So, we designed all our examples to use a secrets.py file, that is in your CIRCUITPY drive, to hold secret/private/custom data. That way you can share your main project without worrying about accidentally sharing private stuff.

Your secrets.py file should look like this:

# This file is where you keep secret settings, passwords, and tokens! # If you put them in the code you risk committing that info or sharing it

secrets = { 'ssid' : 'home_wifi_network', 'password' : 'wifi_password', 'aio_username' : 'my_adafruit_io_username', 'aio_key' : 'my_adafruit_io_key', 'timezone' : "America/New_York", # http://worldtimeapi.org/timezones }

Copy and paste that text/code into a file called secrets.py and save it to your CIRCUITPY folder like so:

Inside is a python dictionary named secrets with a line for each entry. Each entry has an entry name (say 'ssid' ) and then a colon to separate it from the entry key 'home ssid' and finally a comma ,

At a minimum you'll need to adjust the ssid and password for your local WiFi setup so do that now!

As you make projects you may need more tokens and keys, just add them one line at a time. See for example other tokens such as one for accessing github or the hackaday API. Other non-secret data like your timezone can also go here, just cause its called secrets doesn't mean you can't have general customization data in there!

For the correct time zone string, look at http://worldtimeapi.org/timezones (https://adafru.it/EcP) and remember that if your city is not listed, look for a city in the same time zone, for example Boston, New York, Philadelphia, Washington DC, and Miami are all on the same time as New York.

Of course, don't share your secrets.py - keep that out of GitHub, Discord or other project-sharing sites.

 Don't share your secrets.py file, it has your passwords and API keys in it!

Connect to WiFi

OK now you have your secrets setup - you can connect to the Internet using the Requests module.

First make sure you are running the latest version of Adafruit CircuitPython (https://adafru.it/Amd) for your board.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle (https://adafru.it/zdx). Our introduction guide has a great page on how to install the library bundle (https://adafru.it/ABU).

adafruit_requests

neopixel

Before continuing make sure your board's CIRCUITPY/lib folder or root filesystem has the above files

copied over.

Once that's done, load up the following example using Mu or your favorite editor:

import ipaddress import ssl import wifi import socketpool import adafruit_requests

# URLs to fetch from TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html" JSON_QUOTES_URL = "https://www.adafruit.com/api/quotes.php" JSON_STARS_URL = "https://api.github.com/repos/adafruit/circuitpython"

# Get wifi details and more from a secrets.py file try: from secrets import secrets except ImportError: print("WiFi secrets are kept in secrets.py, please add them there!") raise

print("ESP32-S2 WebClient Test")

print("My MAC addr:", [hex(i) for i in wifi.radio.mac_address])

print("Available WiFi networks:") for network in wifi.radio.start_scanning_networks(): print("\t%s\t\tRSSI: %d\tChannel: %d" % (str(network.ssid, "utf-8"), network.rssi, network.channel)) wifi.radio.stop_scanning_networks()

print("Connecting to %s"%secrets["ssid"]) wifi.radio.connect(secrets["ssid"], secrets["password"]) print("Connected to %s!"%secrets["ssid"]) print("My IP address is", wifi.radio.ipv4_address)

ipv4 = ipaddress.ip_address("8.8.4.4") print("Ping google.com: %f ms" % (wifi.radio.ping(ipv4)*1000))

pool = socketpool.SocketPool(wifi.radio) requests = adafruit_requests.Session(pool, ssl.create_default_context())

print("Fetching text from", TEXT_URL) response = requests.get(TEXT_URL) print("-" * 40) print(response.text) print("-" * 40)

print("Fetching json from", JSON_QUOTES_URL) response = requests.get(JSON_QUOTES_URL) print("-" * 40) print(response.json()) print("-" * 40)

print()

print("Fetching and parsing json from", JSON_STARS_URL) response = requests.get(JSON_STARS_URL) print("-" * 40) print("CircuitPython GitHub Stars", response.json()["stargazers_count"]) print("-" * 40)

print("done")

And save it to your board. Make sure the file is named code.py.

Open up your REPL, you should see something like the following:

In order, the example code...

Checks the ESP32-S2's MAC address.

print("My MAC addr:", [hex(i) for i in wifi.radio.mac_address])

Performs a scan of all access points and prints out the access point's name (SSID), signal strength (RSSI), and channel.

print("Avaliable WiFi networks:") for network in wifi.radio.start_scanning_networks(): print("\t%s\t\tRSSI: %d\tChannel: %d" % (str(network.ssid, "utf-8"), network.rssi, network.channel)) wifi.radio.stop_scanning_networks()

Connects to the access point you defined in the secrets.py file, prints out its local IP address, and attempts to ping google.com to check its network connectivity.

print("Connecting to %s"%secrets["ssid"]) wifi.radio.connect(secrets["ssid"], secrets["password"]) print(print("Connected to %s!"%secrets["ssid"])) print("My IP address is", wifi.radio.ipv4_address)

ipv4 = ipaddress.ip_address("8.8.4.4") print("Ping google.com: %f ms" % wifi.radio.ping(ipv4))

The code creates a socketpool using the wifi radio's available sockets. This is performed so we don't need to re-use sockets. Then, it initializes a a new instance of the requests (https://adafru.it/E9o) interface which makes getting data from the internet

really really easy.

pool = socketpool.SocketPool(wifi.radio) requests = adafruit_requests.Session(pool, ssl.create_default_context())

To read in plain-text from a web URL, call requests.get - you may pass in either a http, or a http s url for SSL connectivity.

print("Fetching text from", TEXT_URL) response = requests.get(TEXT_URL) print("-" * 40) print(response.text) print("-" * 40)

Requests can also display a JSON-formatted response from a web URL using a call to requests.get .

print("Fetching json from", JSON_QUOTES_URL) response = requests.get(JSON_QUOTES_URL) print("-" * 40) print(response.json()) print("-" * 40)

Finally, you can fetch and parse a JSON URL using requests.get . This code snippet obtains the

stargazers_count field from a call to the GitHub API.

print("Fetching and parsing json from", JSON_STARS_URL) response = requests.get(JSON_STARS_URL) print("-" * 40) print("CircuitPython GitHub Stars", response.json()["stargazers_count"]) print("-" * 40)

OK you now have your ESP32-S2 board set up with a proper secrets.py file and can connect over the Internet. If not, check that your secrets.py file has the right ssid and password and retrace your steps until you get the Internet connectivity working!

Getting The Date & Time

A very common need for projects is to know the current date and time. Especially when you want to deep sleep until an event, or you want to change your display based on what day, time, date, etc. it is

Determining the correct local time is really really hard. There are various time zones, Daylight Savings dates, leap seconds, etc. Trying to get NTP time and then back-calculating what the local time is, is

extraordinarily hard on a microcontroller just isn't worth the effort and it will get out of sync as laws change anyways.

For that reason, we have the free adafruit.io time service. Free for anyone, with a free adafruit.io account. You

do need an account

because we have to keep accidentally mis-programmed-board from

overwhelming adafruit.io and lock them out temporarily. Again, it's free!

 There are other services like WorldTimeAPI, but we don't use those for our guides because they are nice people and we don't want to accidentally overload their site. Also, there's a chance it may eventually go down or also require an account.

Step 1) Make an Adafruit account

It's free! Visit https://accounts.adafruit.com/ (https://adafru.it/dyy) to register and make an account if you do not already have one

Step 2) Sign into Adafruit IO

Head over to io.adafruit.com (https://adafru.it/fsU) and click Sign In to log into IO using your Adafruit account. It's free and fast to join.

Step 3) Get your Adafruit IO Key

Click on My Key in the top bar

You will get a popup with your Username and Key (In this screenshot, we've covered it with red blocks)

Go to your secrets.py file on your CIRCUITPY drive and add three lines for aio_username , aio_key and

timezone so you get something like the following:

# This file is where you keep secret settings, passwords, and tokens! # If you put them in the code you risk committing that info or sharing it

secrets = { 'ssid' : 'home_wifi_network', 'password' : 'wifi_password', 'aio_username' : 'my_adafruit_io_username', 'aio_key' : 'my_adafruit_io_key', 'timezone' : "America/New_York", # http://worldtimeapi.org/timezones }

The timezone is optional, if you don't have that entry, adafruit.io will guess your timezone based on geographic IP address lookup. You can visit http://worldtimeapi.org/timezones (https://adafru.it/EcP) to see all the time zones available (even though we do not use worldtimeapi for time-keeping we do use the same time zone table)

Step 4) Upload Test Python Code

This code is like the Internet Test code from before, but this time it will connect to adafruit.io and get the local time

import ipaddress import ssl import wifi import socketpool import adafruit_requests import secrets

TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html" JSON_QUOTES_URL = "https://www.adafruit.com/api/quotes.php" JSON_STARS_URL = "https://api.github.com/repos/adafruit/circuitpython"

# Get wifi details and more from a secrets.py file try: from secrets import secrets except ImportError: print("WiFi secrets are kept in secrets.py, please add them there!") raise

# Get our username, key and desired timezone aio_username = secrets["aio_username"] aio_key = secrets["aio_key"] location = secrets.get("timezone", None) TIME_URL = "https://io.adafruit.com/api/v2/%s/integrations/time/strftime?x-aio-key=%s" % (aio_username, aio_key) TIME_URL += "&fmt=%25Y-%25m-%25d+%25H%3A%25M%3A%25S.%25L+%25j+%25u+%25z+%25Z"

print("ESP32-S2 Adafruit IO Time test")

print("My MAC addr:", [hex(i) for i in wifi.radio.mac_address])

print("Available WiFi networks:") for network in wifi.radio.start_scanning_networks(): print("\t%s\t\tRSSI: %d\tChannel: %d" % (str(network.ssid, "utf-8"), network.rssi, network.channel)) wifi.radio.stop_scanning_networks()

print("Connecting to %s"%secrets["ssid"]) wifi.radio.connect(secrets["ssid"], secrets["password"]) print("Connected to %s!"%secrets["ssid"]) print("My IP address is", wifi.radio.ipv4_address)

ipv4 = ipaddress.ip_address("8.8.4.4") print("Ping google.com: %f ms" % wifi.radio.ping(ipv4))

pool = socketpool.SocketPool(wifi.radio) requests = adafruit_requests.Session(pool, ssl.create_default_context())

print("Fetching text from", TIME_URL) response = requests.get(TIME_URL) print("-" * 40) print(response.text) print("-" * 40)

After running this, you will see something like the below text. We have blocked out the part with the secret username and key data!

Note at the end you will get the date, time, and your timezone! If so, you have correctly configured your secrets.py and can continue to the next steps!

MagTag-Specific CircuitPython Libraries

To use all the amazing features of your MagTag with CircuitPython, you must first install a number of libraries. This page covers that process.

Get Latest Adafruit CircuitPython Bundle

Download the Adafruit CircuitPython Library Bundle. You can find the latest release here:

https://adafru.it/ENC

Download the adafruit-circuitpython-bundle-version-mpy-*.zip bundle zip file, and unzip a folder of the same name. Inside you'll find a lib folder. The entire collection of libraries is too large to fit on the CIRCUITPY drive. Therefore, you'll need to copy the necessary libraries to your board individually.

At a minimum, the following libraries are required. Copy the following folders or .mpy files to the lib folder on your CIRCUITPY drive. If the library is a folder, copy the entire folder to the lib folder on your board.

Library folders (copy the whole folder over to lib):

adafruit_magtag - This is a helper library designed for using all of the features of the MagTag, including networking, buttons, NeoPixels, etc.

adafruit_portalbase - This library is the base library that adafruit_magtag is built on top of. adafruit_bitmap_font - There is fancy font support, and it's easy to make new fonts. This library reads

and parses font files.

adafruit_display_text - This library displays text on the screen. adafruit_io - This library helps connect the MagTag to our free data logging and viewing service

Library files:

adafruit_requests.mpy - This library allows us to perform HTTP requests and get responses back from servers. GET/POST/PUT/PATCH - they're all in here!

adafruit_fakerequests.mpy - This library allows you to create fake HTTP requests by using local files. adafruit_miniqr.mpy - QR creation library lets us add easy-to-scan 2D barcodes to the E-Ink display neopixel.mpy - This library is used to control the onboard NeoPixels. simpleio.mpy - This library is used for tone generation.

Secrets

Even if you aren't planning to go online with your MagTag, you'll need to have a secrets.py file in the root directory (top level) of your CIRCUITPY drive. If you do not intend to connect to wireless, it does not need to have valid data in it. Here's more info on the secrets.py file (https://adafru.it/P3b).

https://adafru.it/ENC

Simple Flashcards

We’ll start off by working through a quick app that just does the very basics we need to study. It’ll load up some cards out of a JSON file, shuffle them, and go through them one at a time as you press the D button on the MagTag. In the next section, we’ll add some fancier features, like sorting your cards into categories, and letting you pick which ones you’d like to study per session.

In this code, we’ll be using a PCF font for international character sets. PCF fonts offer a little extra efficiency compared to raw BDF (bitmap) fonts, so they’re easier to fit on CircuitPython drives. We’ll be using one today for the Japanese Hiragana and Katakana characters used in this deck.

Download the Software

Download the code by clicking the "Download: Project Zip" and copy the files to the CIRCUITPY flash drive that appears on your computer when you plug your MagTag in to your computer via a known good USB cable.

Here's the program we'll be running on the code.py file in the CIRCUITPY drive.

import time import json import terminalio import digitalio import random from adafruit_magtag.magtag import MagTag

# Set up the magtag print("Magtag Basic Flashcards") magtag = MagTag()

# Import cards cards = {} with open("deck.json") as fp: cards = json.load(fp)

# Create a text area magtag.add_text( text_font="yasashi20.pcf", text_position=( magtag.graphics.display.width // 2, magtag.graphics.display.height // 2, ), line_spacing=0.85, text_anchor_point=(0.5, 0.5), )

# Set up buttons cur_btn = False prev_btn = False

while True: # Shuffle the deck cards = sorted(cards, key=lambda _: random.random()) for card in cards:

# Show the first side and wait for the D button text = ''.join(magtag.wrap_nicely(card[0], 20)) magtag.set_text(text) while True: cur_btn = magtag.peripherals.button_d_pressed if cur_btn and not prev_btn: print("Show Result") time.sleep(0.1) break prev_btn = cur_btn

# Show the second side and wait for the D button text = '\n'.join(magtag.wrap_nicely(card[1], 11)) text += '\n' text += '\n'.join(magtag.wrap_nicely(card[2], 20)) print(text) magtag.set_text(text) while True: cur_btn = magtag.peripherals.button_d_pressed if cur_btn and not prev_btn: print("Next Card") time.sleep(0.1) break prev_btn = cur_btn

Example Deck

In addition, here's an example "deck" of cards, written in JSON. In case you've never used JSON before, it stands for JavaScript Object Notation: it's a format of writing data (like arrays and key-value pairs) that was originally derived from Javascript but is now commonly used across many different programming languages. In this example deck file, we create a list of lists, using square brackets [] to enclose the lists

and commas , to separate list elements.

[ ["Monday","げつ　ようび","Getsu yōbi"], ["Tuesday","か　ようび","Ka yōbi"], ["Wednesday","すい　ようび","Sui yōbi"], ["Thursday","もく　ようび","Moku yōbi"], ["Friday","きん　ようび","Kin yōbi"], ["Saturday","ど　ようび","Do yōbi"], ["Sunday","にち　ようび","Nichi yōbi"] ]

This particular example is written for studying Japanese, but it should work fine for any topic you want Spanish, geography, code reference, obscure Star Trek trivia, whatever. Just make sure to tweak the textdisplaying parts of the code if you add or remove “sections” of the card structure.

How does it work?

Let's walk through this code step by step. First, we import all the required libraries, and create an object for the magtag that contains all the library features, like detecting button presses. We'll also tell the Serial Port we've started up the program.

import time import json import terminalio import digitalio import random from adafruit_magtag.magtag import MagTag

# Set up the magtag print("Magtag Basic Flashcards") magtag = MagTag()

Then, we use the json library to open our deck file, and interpret the JSON syntax into a list-of-lists that we can use in Python.

# Import cards cards = {} with open("deck.json") as fp: cards = json.load(fp)

As the last part of our setup, we create a text object to hold the sides of our flashcard. This uses the Yasashi 20 point PCF font, which contains both english and Japanese Hira and Katakana characters (no Kanji, though, sadly - that's a bit too much for the size of the Magtag's memory).

We'll put it right in the center of the screen.

# Create a text area magtag.add_text( text_font="yasashi20.pcf", text_position=( magtag.graphics.display.width // 2, magtag.graphics.display.height // 2, ), line_spacing=0.85, text_anchor_point=(0.5, 0.5), )

To actually change the sides of the card, and to move to the next card, we'll need to detect when a magtag button is pressed.

The magtag library contains the attribute magtag.peripherals.button_d_pressed , which will tell us whether the D button is currently up or down. But this value by itself isn't able to detect

when

the button is pressed. To

do that, we'll create a couple of memory variables:

cur_btn = False prev_btn = False

Whenever we want to wait for a button press, we'll enter a short while loop, and do nothing until we see the button change from an "up" state to a "down" state.

while True: cur_btn = magtag.peripherals.button_d_pressed if cur_btn and not prev_btn: print("Show Result") time.sleep(0.1) break prev_btn = cur_btn

Before we actually start using the deck, we want to make sure it isn't in the same order every time. Circuitpython doesn't have access to the random.shuffle() function, but we can fake it by using the built in

function sorted() and indexes from random.random() to achieve the same effect.

cards = sorted(cards, key=lambda _: random.random())

When we want to display text, we use the built in magtag set_text function. By using wrap_nicely , we can make sure that the card text won't ever go off the side of the magtag - note that characters from other

languages (like Hiragana) can be larger than roman ones, so expect to change the length parameter based on the kind of text you want to display.

# Example Hira wrapping (fewer characters) text = '\n'.join(magtag.wrap_nicely(card[1], 11)) # Example Roman wrapping (more characters) text += '\n'.join(magtag.wrap_nicely(card[2], 20)) # Set the contents of the text field magtag.set_text(text)

We combine all these elements into the program's final main loop, which will run through the cards in a random order forever, waiting on user button presses to move forward.

while True: # Shuffle the deck cards = sorted(cards, key=lambda _: random.random()) for card in cards:

# Show the first side and wait for the D button text = ''.join(magtag.wrap_nicely(card[0], 20)) magtag.set_text(text) while True: cur_btn = magtag.peripherals.button_d_pressed if cur_btn and not prev_btn: print("Show Result") time.sleep(0.1) break prev_btn = cur_btn

# Show the second side and wait for the D button text = '\n'.join(magtag.wrap_nicely(card[1], 11)) text += '\n' text += '\n'.join(magtag.wrap_nicely(card[2], 20)) print(text) magtag.set_text(text) while True: cur_btn = magtag.peripherals.button_d_pressed if cur_btn and not prev_btn: print("Next Card") time.sleep(0.1) break prev_btn = cur_btn

Complicated Flashcards

Our simple flashcard app already has some advantages over physical cards. But there are other features we could add. We might want to narrow down the cards we want to study, or sort them into topics, and it would be nice to revisit cards that we got wrong and want to study again. We're also missing a lot of basic UI features like labels and feedback.

In this expanded example, we'll add some new features to make this app a little more advanced, such as:

A new JSON format to support multiple "chapters" of a deck A simple menu, allowing us to pick specific parts of our deck to study from New text areas to label the buttons and give the user more directions NeoPixel feedback after a user hits a button (a nice-to-have, since the e-paper screen is sloooow) Automatically add cards the user marks as "forgotten" back into the deck to be studied again.

Download the Software

Download the code by clicking the "Download: Project Zip" and copy the files to the CIRCUITPY flash drive that appears on your computer when you plug your MagTag in to your computer via a known good USB cable.

Here's the program we'll be running on the code.py file in the CIRCUITPY drive.

import time import json import terminalio import digitalio import random from adafruit_display_shapes.rect import Rect from adafruit_magtag.magtag import MagTag magtag = MagTag()

# --------------------------------# Prepare text regions # ---------------------------------

# Fetch list of chapters MAX_LLEN = 8 data = {} with open("deck.json") as fp: data = json.load(fp) chap_list = list(data.keys()) num_chap = len(chap_list) list_len = min(num_chap,MAX_LLEN)

# Print list of chapters for i in range(list_len): magtag.add_text( text_font=terminalio.FONT, text_position=(10, 3+(i*10)), line_spacing=1.0, text_anchor_point=(0, 0), # Top left is_data=False, # Text will be set manually ) if i == 0: magtag.set_text("> " + chap_list[i], i, auto_refresh=False) else: magtag.set_text(" " + chap_list[i], i, auto_refresh=False)

# Add button labels at the bottom of the screen BUTTON_TEXT_IDX = list_len magtag.graphics.splash.append(Rect(0, magtag.graphics.display.height - 14, magtag.graphics.display.width, magtag.graphics.display.height, fill=0x0)) magtag.add_text( text_font=terminalio.FONT, text_position=(3, magtag.graphics.display.height - 14), text_color=0xFFFFFF, line_spacing=1.0, text_anchor_point=(0, 0), # Top left is_data=False, # Text will be set manually ) magtag.set_text("Select Up Down Begin", BUTTON_TEXT_IDX, auto_refresh=False)

# Add message label at the top of the screen MSG_TEXT_IDX = list_len + 1 magtag.add_text( text_font=terminalio.FONT, text_position=(3, magtag.graphics.display.height - 30), line_spacing=1.0, text_anchor_point=(0, 0), # Top left is_data=False, # Text will be set manually ) magtag.set_text("Press Begin to default to all chapters", MSG_TEXT_IDX)

# Empty text region for card displays CARD_TEXT_IDX = list_len + 2 magtag.add_text( text_font="yasashi20.pcf", text_position=( magtag.graphics.display.width // 2, magtag.graphics.display.height // 2, ), line_spacing=0.85, text_anchor_point=(0.5, 0.5), )

# Button management curr_btns = [False] * 4 prev_btns = [False] * 4 BTN_A = 0 BTN_B = 1 BTN_C = 2 BTN_D = 3 def update_button(idx, pressed): curr_btns[idx] = pressed if curr_btns[idx] and not prev_btns[idx]: print("Exit menu") return True prev_btns[idx] = curr_btns[idx] return False

# Cursor settings cursor_pos = 0 list_offset = 0 selected = [False] * num_chap btn_updated = False

# --------------------------------# Program Loop

# ---------------------------------

while True:

# -------------------------------- # Chapter Select # ---------------------------------

while True: if btn_updated: # Clear default message only when items are selected if any(selected): magtag.set_text("", MSG_TEXT_IDX, auto_refresh=False) else: magtag.set_text("Press Begin to default to all chapters", MSG_TEXT_IDX, auto_refresh=False)

magtag.peripherals.neopixels.fill((128, 0, 0)) for i in range(list_len): prefix = "" if i == cursor_pos: prefix += ">" else: prefix += " " if selected[i + list_offset]: prefix += "*" else: prefix += " " magtag.set_text(prefix + chap_list[i+list_offset], i, auto_refresh=False) magtag.refresh() magtag.peripherals.neopixels.fill((0, 0, 0)) btn_updated = False # UP if update_button(BTN_B, magtag.peripherals.button_b_pressed): cursor_pos -= 1 btn_updated = True # DOWN if update_button(BTN_C, magtag.peripherals.button_c_pressed): cursor_pos += 1 btn_updated = True # SELECT if update_button(BTN_A, magtag.peripherals.button_a_pressed): selected[cursor_pos + list_offset] = not selected[cursor_pos + list_offset] btn_updated = True # BEGIN if update_button(BTN_D, magtag.peripherals.button_d_pressed): # if nothing was selected, default to all decks magtag.peripherals.neopixels.fill((128, 0, 0)) if not any(selected): selected = [True] * list_len break # detect if you're past the list bounds if cursor_pos == MAX_LLEN: cursor_pos = MAX_LLEN - 1 if (num_chap - list_offset - 1) > MAX_LLEN: list_offset += 1

if cursor_pos == -1: cursor_pos = 0 if list_offset > 0: list_offset -= 1

# --------------------------------- # Deck Loop # ---------------------------------

# Clear the menu and message box for i in range(list_len): magtag.set_text("", i, auto_refresh=False) magtag.set_text("", MSG_TEXT_IDX,auto_refresh=False)

# Grab the cards from the chapters we want, and shuffle them cards = [] for i in range(len(selected)): if selected[i]: cards.extend(data[chap_list[i]]) cards = sorted(cards, key=lambda _: random.random())

# make a separate holding deck for cards the user gets wrong forgotten_cards = []

exit_called = False while True: for card in cards: magtag.set_text("Exit -- -- Turn Over", BUTTON_TEXT_IDX,auto_refresh=False) text = '\n'.join(magtag.wrap_nicely(card[0], 11)) magtag.set_text(text, CARD_TEXT_IDX) magtag.peripherals.neopixels.fill((0, 0, 0))

while True: # EXIT if update_button(BTN_A, magtag.peripherals.button_a_pressed): exit_called = True break # TURN if update_button(BTN_D, magtag.peripherals.button_d_pressed): break magtag.peripherals.neopixels.fill((128, 0, 0)) if exit_called: break

magtag.set_text("Exit -- Forgot Good", BUTTON_TEXT_IDX,auto_refresh=False) text = '\n'.join(magtag.wrap_nicely(card[1], 11)) text += '\n' text += '\n'.join(magtag.wrap_nicely(card[2], 20)) magtag.set_text(text, CARD_TEXT_IDX) magtag.peripherals.neopixels.fill((0, 0, 0))

while True: # EXIT if update_button(BTN_A, magtag.peripherals.button_a_pressed): exit_called = True break # FORGOT if update_button(BTN_C, magtag.peripherals.button_c_pressed): forgotten_cards.append(card) break # GOOD if update_button(BTN_D, magtag.peripherals.button_d_pressed): break magtag.peripherals.neopixels.fill((128, 0, 0)) if exit_called: break # Next card

# If there were forgotten cards, make them the new deck and restart if forgotten_cards: cards = forgotten_cards forgotten_cards = [] else: break

# -------------------------------- # Complete and Reset # ---------------------------------

# Show completion text if deck was finished if not exit_called: magtag.set_text("-- -- -- --", BUTTON_TEXT_IDX,auto_refresh=False) magtag.set_text("Complete!", CARD_TEXT_IDX) else: exit_called = False

# Clear and reprint list of chapters magtag.set_text("", CARD_TEXT_IDX, auto_refresh=False) for i in range(list_len): if i == 0: magtag.set_text("> " + chap_list[i], i, auto_refresh=False) else: magtag.set_text(" " + chap_list[i], i, auto_refresh=False) magtag.set_text("Select Up Down Begin", BUTTON_TEXT_IDX, auto_refresh=False) magtag.set_text("Press Begin to default to all chapters", MSG_TEXT_IDX)

# Reset cursor: cursor_pos = 0 list_offset = 0 selected = [False] * list_len btn_updated = False

# Done resetting, return to chapter selection magtag.peripherals.neopixels.fill((0, 0, 0))

New Deck Format

For our new deck, we want to start organizing cards by "chapter" - like different topics in a language, or different chapters in a textbook. To do this, we use the key-value syntax in JSON.

Instead of being a big list of smaller lists, the top level is now equivalent to a Python Dictionary, using curly brackets {} . Each chapter name has a list of cards associated with it. In our final program, we'll be able to

study chapters by themselves or combine them together using the list of chapter names.

{ "Everyday Phrases":[ ["You're Welcome", "どういたしまして", "Dō Itashimashite"], ["Good Morning", "おはようございます", "Ohayō gozaimasu"], ["Yes", "はい", "Hai"], ["No", "いいえ", "Iie"], ["Hello", "こんにちは", "Konnichi wa"], ["Please", "おねがいします", "Onegai Shimasu"], ["Excuse Me", "すみません", "Sumimasen"], ["Thank You", "ありがとう", "Arigatō"], ], "Days of the Week":[ ["Monday","げつ　ようび","Getsu yōbi"], ["Tuesday","か　ようび","Ka yōbi"], ["Wednesday","すい　ようび","Sui yōbi"], ["Thursday","もく　ようび","Moku yōbi"], ["Friday","きん　ようび","Kin yōbi"], ["Saturday","ど　ようび","Do yōbi"], ["Sunday","にち　ようび","Nichi yōbi"], ], "Animals":[ ["Dog","いぬ","Inu"], ["Cat","ねこ","Neko"], ["Horse","うま","Uma"], ["Monkey","さる","Saru"], ["Elephant","ぞう","Zō"], ["Rabbit","うさぎ","Usagi"], ] }

Program Flow

This program has a couple of different modes, so we'll go over how it works first.

The user starts by seeing a list of the chapters in their deck, along with a line of button labels. Hitting the Begin button right away will simply combine all the cards into one big study session and start up, but they can also pick specific chapters to focus on.

Users can move up and down the list with the arrow buttons, and select different chapters with the select button. Once they've picked the chapters you want to study, the Begin button will start a session for only cards from those chapters.

After a user turns a card over, they can press the "Forgot" button to mark it as incorrect. Forgotten cards automatically get added to the end of the deck, so once they've finished the original set, they'll need to study those cards again.

Once every card has been marked "good", the session is complete! A congratulatory message shows, and the user returns to the menu.

Code Walkthrough

Setup:

Just like the previous version, we start by importing the libraries we need, but note that we're using a new one, Adafruit Shapes, which will be a part of our background display.

import time import json import terminalio import digitalio import random from adafruit_display_shapes.rect import Rect from adafruit_magtag.magtag import MagTag magtag = MagTag()

The file import section comes with some extra steps.

If the user has a LOT of chapters, we won't be able to fit them all on the screen at once, so we set a maximum number of lists to display at one time with MAX_LLEN . Lists over this number won't be shown

unless the list is scrolled down.

We're going to start off by displaying all the chapters in a list, so we extract their names into a variable called chap_list . We also store the total number of chapters with num_chap .

Finally, if the list of chapters is shorter than MAX_LLEN , we won't need to scroll. So we find the actual length of the list we're displaying by comparing the two variables and picking the minimum.

MAX_LLEN = 8 data = {} with open("deck.json") as fp: data = json.load(fp) chap_list = list(data.keys()) num_chap = len(chap_list) list_len = min(num_chap,MAX_LLEN)

After importing the deck, we set up the various text regions. We create one for each item in the menu list, and then add on the button labels, background shape, and a special message region for telling the user about the "default" option if they don't actually pick any chapters.

We also create an empty text region that will eventually hold the flashcards themselves. Since the user moves back and forth between the menu selection and the cards, we won't actually delete any objects when we change modes - instead, we'll just fill the menu-specific text fields with empty strings when in flashcard mode, and vice versa for menu mode.

# Print list of chapters for i in range(list_len): magtag.add_text( text_font=terminalio.FONT, text_position=(10, 3+(i*10)), line_spacing=1.0, text_anchor_point=(0, 0), # Top left is_data=False, # Text will be set manually ) if i == 0: magtag.set_text("> " + chap_list[i], i, auto_refresh=False) else: magtag.set_text(" " + chap_list[i], i, auto_refresh=False)

# Add button labels at the bottom of the screen BUTTON_TEXT_IDX = list_len magtag.graphics.splash.append(Rect(0, magtag.graphics.display.height - 14, magtag.graphics.display.width, magtag.graphics.display.height, fill=0x0)) magtag.add_text( text_font=terminalio.FONT, text_position=(3, magtag.graphics.display.height - 14), text_color=0xFFFFFF, line_spacing=1.0, text_anchor_point=(0, 0), # Top left is_data=False, # Text will be set manually ) magtag.set_text("Select Up Down Begin", BUTTON_TEXT_IDX, auto_refresh=False)

# Add message label at the top of the screen MSG_TEXT_IDX = list_len + 1 magtag.add_text( text_font=terminalio.FONT, text_position=(3, magtag.graphics.display.height - 30), line_spacing=1.0, text_anchor_point=(0, 0), # Top left is_data=False, # Text will be set manually ) magtag.set_text("Press Begin to default to all chapters", MSG_TEXT_IDX)

# Empty text region for card displays CARD_TEXT_IDX = list_len + 2 magtag.add_text( text_font="yasashi20.pcf", text_position=( magtag.graphics.display.width // 2, magtag.graphics.display.height // 2, ), line_spacing=0.85, text_anchor_point=(0.5, 0.5), )

Remember the button code from the simple flashcards example? We don't need to change it much, but we do need to support all 4 buttons rather than just one. So we adapt the old code into a new function that can determine out the button status by index (unfortunately, the magtag library attributes aren't indexable, so you still need to pass those in too).

# Button management curr_btns = [False] * 4 prev_btns = [False] * 4 BTN_A = 0 BTN_B = 1 BTN_C = 2 BTN_D = 3 def update_button(idx, pressed): curr_btns[idx] = pressed if curr_btns[idx] and not prev_btns[idx]: print("Exit menu") return True prev_btns[idx] = curr_btns[idx] return False

As the final part of the setup process, we need some miscellaneous variables like the cursor location, the scrolling offset for long lists, what list items have been selected, and whether any buttons have been updated.

cursor_pos = 0 list_offset = 0 selected = [False] * num_chap btn_updated = False

Chapter Selection:

Now we can get started with the main program loop. The first screen the user sees is the chapter selection, where they can move a cursor up and down to select chapters. We've already printed out all the text on this screen in the setup stage, so this is basically just a big loop to read buttons.

We have four different button detectors. The Up and Down buttons change the cursor position, Select changes the status of the chapter in the Selected array, and Begin signals to exit the loop and start studying flashcards (combining all of the chapters, if nothing was selected).

# UP if update_button(BTN_B, magtag.peripherals.button_b_pressed): cursor_pos -= 1 btn_updated = True # DOWN if update_button(BTN_C, magtag.peripherals.button_c_pressed): cursor_pos += 1 btn_updated = True # SELECT if update_button(BTN_A, magtag.peripherals.button_a_pressed): selected[cursor_pos + list_offset] = not selected[cursor_pos + list_offset] btn_updated = True # BEGIN if update_button(BTN_D, magtag.peripherals.button_d_pressed): # if nothing was selected, default to all decks magtag.peripherals.neopixels.fill((128, 0, 0)) if not any(selected): selected = [True] * list_len break

If a button gets pressed, the program goes over the list of text areas and makes any required changes, like moving the cursor, adding * asterisks to selected chapters, and setting the current user message, all

before refreshing the e-paper.

if btn_updated: # Clear default message only when items are selected if any(selected): magtag.set_text("", MSG_TEXT_IDX, auto_refresh=False) else: magtag.set_text("Press Begin to default to all chapters", MSG_TEXT_IDX, auto_refresh=False)

magtag.peripherals.neopixels.fill((128, 0, 0)) for i in range(list_len): prefix = "" if i == cursor_pos: prefix += ">" else: prefix += " " if selected[i + list_offset]: prefix += "*" else: prefix += " " magtag.set_text(prefix + chap_list[i+list_offset], i, auto_refresh=False) magtag.refresh() magtag.peripherals.neopixels.fill((0, 0, 0)) btn_updated = False

What's with the neopixel code? Since the e-paper updates slowly in comparison to how quickly we can push buttons, it's nice to give the user a little feedback that they've actually started an action.

So every time a button is pressed, we turn on the neopixels, and once the e-paper is finished updating and the buttons are ready to be pushed again, we turn it off.

magtag.peripherals.neopixels.fill((128, 0, 0)) magtag.peripherals.neopixels.fill((0, 0, 0))

Finally, if the chapter list is over the maximum list length, the user can scroll. This will only happen when the cursor is at the very end or very beginning of the list, and it doesn't affect things like chapter selection, which is the same no matter how the list is offset.

if cursor_pos == MAX_LLEN: cursor_pos = MAX_LLEN - 1 if (num_chap - list_offset - 1) > MAX_LLEN: list_offset += 1

if cursor_pos == -1: cursor_pos = 0 if list_offset > 0: list_offset -= 1

Flashcard Session:

Once a user picks a chapter and hits begin, they move into the deck loop. This is where flashcards get displayed, and it's similar to the basic example earlier in this chapter, with a few additions. First, we clear all the text from the menu mode:

# Clear the menu and message box for i in range(list_len): magtag.set_text("", i, auto_refresh=False) magtag.set_text("", MSG_TEXT_IDX,auto_refresh=False)

Then, we create a list of cards for this specific session, by combining all the cards from the chapters that were selected in the menu, and shuffling them.

cards = [] for i in range(len(selected)): if selected[i]: cards.extend(data[chap_list[i]]) cards = sorted(cards, key=lambda _: random.random())

In python, you can't add to a list while you're iterating through it. Since we want to keep extending the deck with cards that the user forgot, we'll create a temporary holding list called "forgotten_cards", and add it on later. We'll also create a variable to detect whether the user wants to give up and go back to the menu.

forgotten_cards = [] exit_called = False

Then, we enter the card loop. This is almost the same as the simple example. The only differences are that the user can exit the loop using the Exit button, or add cards to the forgotten_cards list with the Forget

button. If there are any cards in forgotten_cards once the loop is finished, it'll restart the loop with those cards as the new deck, over and over until the user has gotten them all correct.

while True: for card in cards: magtag.set_text("Exit -- -- Turn Over", BUTTON_TEXT_IDX,auto_refresh=False) text = '\n'.join(magtag.wrap_nicely(card[0], 11)) magtag.set_text(text, CARD_TEXT_IDX) magtag.peripherals.neopixels.fill((0, 0, 0))

while True: # EXIT if update_button(BTN_A, magtag.peripherals.button_a_pressed): exit_called = True break # TURN if update_button(BTN_D, magtag.peripherals.button_d_pressed): break magtag.peripherals.neopixels.fill((128, 0, 0)) if exit_called: break

magtag.set_text("Exit -- Forgot Good", BUTTON_TEXT_IDX,auto_refresh=False) text = '\n'.join(magtag.wrap_nicely(card[1], 11)) text += '\n' text += '\n'.join(magtag.wrap_nicely(card[2], 20)) magtag.set_text(text, CARD_TEXT_IDX) magtag.peripherals.neopixels.fill((0, 0, 0))

while True: # EXIT if update_button(BTN_A, magtag.peripherals.button_a_pressed): exit_called = True break # FORGOT if update_button(BTN_C, magtag.peripherals.button_c_pressed): forgotten_cards.append(card) break # GOOD if update_button(BTN_D, magtag.peripherals.button_d_pressed): break magtag.peripherals.neopixels.fill((128, 0, 0)) if exit_called: break # Next card # If there were forgotten cards, make them the new deck and restart if forgotten_cards: cards = forgotten_cards forgotten_cards = [] else: break

Wrapping up:

Once the user has finished a study session, all that's left is to clean up the screen and reset everything back to how it started. We'll send them a message if they completed the deck (rather than exiting), and turn off any LEDs or variables that might have been set.

# Show completion text if deck was finished if not exit_called: magtag.set_text("-- -- -- --", BUTTON_TEXT_IDX,auto_refresh=False) magtag.set_text("Complete!", CARD_TEXT_IDX) else: exit_called = False

# Clear and reprint list of chapters magtag.set_text("", CARD_TEXT_IDX, auto_refresh=False) for i in range(list_len): if i == 0: magtag.set_text("> " + chap_list[i], i, auto_refresh=False) else: magtag.set_text(" " + chap_list[i], i, auto_refresh=False) magtag.set_text("Select Up Down Begin", BUTTON_TEXT_IDX, auto_refresh=False) magtag.set_text("Press Begin to default to all chapters", MSG_TEXT_IDX)

# Reset cursor: cursor_pos = 0 list_offset = 0 selected = [False] * list_len btn_updated = False

# Done resetting, return to chapter selection magtag.peripherals.neopixels.fill((0, 0, 0))

Other Resources

Flashcard science is actually a surprisingly broad and well-researched topic! There are lots of modifications that could be added to a program like this to help you learn faster, but weren't a good fit for this tutorial.

The example programs given here should be a good start, but if you'd looking for inspiration on creating your own flashcards, or making modifications to this example program, you can check out the following links.

Pyshuffle (https://adafru.it/PF9): an extension of the program in shown this guide, which shuffles the

vocabulary within card templates to create many similar versions of each card.

Flashcards (Wikipedia): (https://adafru.it/PFa) discusses different kinds of cards and various spaced repetition (https://adafru.it/PFb) systems, such as the Leitner system (https://adafru.it/PFc). The Right Time to Learn (NIH) (https://adafru.it/PFd): if you'd like to get

really

technical, this is a survey paper on the science of spaced repetition learning

Anki (https://adafru.it/PFe): well known open-source spaced repetition software

Font License:

This guide uses the Yasashisa Gothic (やさしさゴシック) (https://adafru.it/PHd) font. It's free for both personal and commercial projects, and uses the IPA license. (https://adafru.it/PHe)

IPA summary from TLDRLegal (https://adafru.it/PHf):

The IPA license applies only to font programs and allows for a great deal of freedom in distributing them, both commercially and non-commercially. You cannot change the name of redistributed versions of the original software and must include a copy of the license, however.

Adafruit Language Flashcards on the MagTag User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual