# MagTag Google Calendar Event Display
## Overview
Danger: This project's code uses the CircuitPython OAuth Library for authentication with Google services. Due to Google's update to the OAuth "authentication flow", the library became incompatible. As a result, this project does not currently work (but may in the future)!
**Keep an eye on your schedule with this MagTag Google Calendar Event Viewer.** This CircuitPython project uses the [Google Calendar API](https://developers.google.com/calendar/) to retrieve a list of the latest events from your Google Calendar and displays them on the MagTag's e-Ink screen.
Between fetching new events on your calendar, the MagTag goes into a deep sleep mode to conserve battery life.
## Parts
The starter kit includes everything you need to use the Adafruit MagTag.
### Adafruit MagTag Starter Kit - ADABOX017 Essentials
[Adafruit MagTag Starter Kit - ADABOX017 Essentials](https://www.adafruit.com/product/4819)
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 is removed! The ESP32-S2 is great because it builds on the years of code and support for the...
Out of Stock
[Buy Now](https://www.adafruit.com/product/4819)
[Related Guides to the Product](https://learn.adafruit.com/products/4819/guides)
Or, you can purchase parts for this project individually.
### Adafruit MagTag - 2.9" Grayscale E-Ink WiFi Display
[Adafruit MagTag - 2.9" Grayscale E-Ink WiFi Display](https://www.adafruit.com/product/4800)
The Adafruit MagTag combines the 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 is removed! The ESP32-S2 is great because it builds on the years of code and support for the ESP32 and also adds...
In Stock
[Buy Now](https://www.adafruit.com/product/4800)
[Related Guides to the Product](https://learn.adafruit.com/products/4800/guides)
### Lithium Ion Polymer Battery with Short Cable - 3.7V 420mAh
[Lithium Ion Polymer Battery with Short Cable - 3.7V 420mAh](https://www.adafruit.com/product/4236)
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 has a capacity of 420mAh for a total of about 1.55 Wh. If you need a larger (or smaller!) battery,
In Stock
[Buy Now](https://www.adafruit.com/product/4236)
[Related Guides to the Product](https://learn.adafruit.com/products/4236/guides)
### Mini Magnet Feet for RGB LED Matrices (Pack of 4)
[Mini Magnet Feet for RGB LED Matrices (Pack of 4)](https://www.adafruit.com/product/4631)
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 **Mini-Magnet Feet.** We got these specifically for our RGB LED Matrices, which no longer...
In Stock
[Buy Now](https://www.adafruit.com/product/4631)
[Related Guides to the Product](https://learn.adafruit.com/products/4631/guides)
### Acrylic + Hardware Kit for Adafruit MagTag
[Acrylic + Hardware Kit for Adafruit MagTag](https://www.adafruit.com/product/4807)
Here is the perfect kit with two faceplate options for your MagTag, including a vivid Red Arrow plate and a dreamy white Cloud plate. And of course, the mounting hardware is included, so you can assemble it with just a plain Phillips screwdriver. Takes less than 3...
In Stock
[Buy Now](https://www.adafruit.com/product/4807)
[Related Guides to the Product](https://learn.adafruit.com/products/4807/guides)
You'll also want to pick up a USB Type C cable to connect the MagTag to your computer.
### USB Type A to Type C Cable - 1ft - 0.3 meter
[USB Type A to Type C Cable - 1ft - 0.3 meter](https://www.adafruit.com/product/4473)
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 totin' around a USB Type A hub, computer or laptop.
USB C is the latest industry-standard connector for...
In Stock
[Buy Now](https://www.adafruit.com/product/4473)
[Related Guides to the Product](https://learn.adafruit.com/products/4473/guides)
### USB Type A to Type C Cable - approx 1 meter / 3 ft long
[USB Type A to Type C Cable - approx 1 meter / 3 ft long](https://www.adafruit.com/product/4474)
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 totin' around a USB Type A hub, computer or laptop.
USB C is the latest industry-standard connector for...
In Stock
[Buy Now](https://www.adafruit.com/product/4474)
[Related Guides to the Product](https://learn.adafruit.com/products/4474/guides)
# MagTag Google Calendar Event Display
## Install CircuitPython
Danger: Make sure that you [update the TinyUF2 Bootloader](https://learn.adafruit.com/adafruit-magtag/update-tinyuf2-bootloader-for-circuitpython-10-4mb-boards-only) before installing CircuitPython!
### Adafruit MagTag - Update TinyUF2 Bootloader for CircuitPython 10 and Later
[Adafruit MagTag](https://learn.adafruit.com/adafruit-magtag)
[Update TinyUF2 Bootloader for CircuitPython 10 and Later](https://learn.adafruit.com/adafruit-magtag/update-tinyuf2-bootloader-for-circuitpython-10-4mb-boards-only)
[CircuitPython](https://github.com/adafruit/circuitpython) is a derivative of [MicroPython](https://micropython.org) 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.
[CircuitPython Download for MagTag](https://circuitpython.org/board/adafruit_magtag_2.9_grayscale/)
Warning: WARNING: The updated Adafruit MagTag 2025 Edition will not work with CircuitPython 9.2.x or earlier. Make sure you install 10.x.x or later!
**Click the link above and download the latest .BIN and .UF2 file**
You can use a 9.x.x release for a pre-2025 MagTag. You **must** use a 10.x.x release for the updated MagTag 2025 Edition.
(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.**
# 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!
Warning: Make sure that you [update the TinyUF2 Bootloader](https://learn.adafruit.com/adafruit-magtag/update-tinyuf2-bootloader-for-circuitpython-10-4mb-boards-only) before following these steps for the UF2 bootloader!
## 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://learn.adafruit.com/adafruit-magtag/install-uf2-bootloader)
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://learn.adafruit.com/adafruit-magtag/rom-bootloader#run-esptool-and-check-connection-3076823-5) 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://learn.adafruit.com/adafruit-magtag/web-serial-esptool) 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.
# MagTag Google Calendar Event Display
## CircuitPython Internet Test
One of the great things about most Espressif microcontrollers are their built-in WiFi capabilities. This page covers the basics of getting connected using CircuitPython.
The first thing you need to do is update your **code.py** to the following (it will error until WiFi details are added). Click the **Download Project Bundle** button to download the necessary libraries and the **code.py** file in a zip file. Extract the contents of the zip file, and copy the **entire** **lib** **folder** and the **code.py** file to your **CIRCUITPY** drive.
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/ESP32_S2_WiFi_Tests/CPy_Native_WiFi_Test/code.py
Your **CIRCUITPY** drive should resemble the following.
To get connected, the next thing you need to do is update the **settings.toml** file.
## The settings.toml 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 **settings.toml** file, that is on your **CIRCUITPY** drive, to hold secret/private/custom data. That way you can share your main project without worrying about accidentally sharing private stuff.
If you have a fresh install of CircuitPython on your board, the initial **settings.toml** file on your **CIRCUITPY** drive is empty.
To get started, you can update the **settings.toml** on your **CIRCUITPY** drive to contain the following code.
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/ESP32_S2_WiFi_Tests/CPy_Native_WiFi_Test/settings.toml
This file should contain a series of Python variables, each assigned to a string. Each variable should describe what it represents (say `wifi_ssid`), followed by an **= ** (equals sign), followed by the data in the form of a Python string (such as `"my-wifi-password"` including the quote marks).
**At a minimum you'll need to add/update your WiFi SSID and WiFi password, 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.
For the correct time zone string, look at [http://worldtimeapi.org/timezones](http://worldtimeapi.org/timezones) 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 **settings.toml** - keep that out of GitHub, Discord or other project-sharing sites.
Warning:
If you connect to the serial console, you should see something like the following:
In order, the example code...
Checks the ESP32's MAC address.
```python
print(f"My MAC address: {[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.
```python
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()
```
Connects to the access point you defined in the **settings.toml** file, and prints out its local IP address.
```python
print(f"Connecting to {os.getenv('WIFI_SSID')}")
wifi.radio.connect(os.getenv("WIFI_SSID"), os.getenv("WIFI_PASSWORD"))
print(f"Connected to {os.getenv('WIFI_SSID')}")
print(f"My IP address: {wifi.radio.ipv4_address}")
```
Attempts to ping a Google DNS server to test connectivity. If a ping fails, it returns `None`. Initial pings can sometimes fail for various reasons. So, if the initial ping is successful (`is not None`), it will print the echo speed in ms. If the initial ping fails, it will try one more time to ping, and then print the returned value. If the second ping fails, it will result in `"Ping google.com: None ms"` being printed to the serial console. Failure to ping does not always indicate a lack of connectivity, so the code will continue to run.
```python
ping_ip = ipaddress.IPv4Address("8.8.8.8")
ping = wifi.radio.ping(ip=ping_ip) * 1000
if ping is not None:
print(f"Ping google.com: {ping} ms")
else:
ping = wifi.radio.ping(ip=ping_ip)
print(f"Ping google.com: {ping} ms")
```
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](http://docs.python-requests.org/en/master/) interface - which makes getting data from the internet _really really easy._
```python
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.
```python
print(f"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`.
```python
print(f"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.
```python
print(f"Fetching and parsing json from {JSON_STARS_URL}")
response = requests.get(JSON_STARS_URL)
print("-" * 40)
print(f"CircuitPython GitHub Stars: {response.json()['stargazers_count']}")
print("-" * 40)
```
OK you now have your ESP32 board set up with a proper **settings.toml** file and can connect over the Internet. If not, check that your **settings.toml** file has the right SSID and password and retrace your steps until you get the Internet connectivity working!
## IPv6 Networking
Starting in CircuitPython 9.2, IPv6 networking is available on most Espressif wifi boards. Socket-using libraries like **adafruit\_requests** and **adafruit\_ntp** will need to be updated to use the new APIs and for now can only connect to services on IPv4.
### IPv6 connectivity & privacy
IPv6 addresses are divided into many special kinds, and many of those kinds (like those starting with **FC** , **FD** , **FE** ) are private or local; Addresses starting with other prefixes like **2002:** and **2001:** are globally routable. In 2024, far from all ISPs and home networks support IPv6 internet connectivity. For more info consult resources like [Wikipedia](https://en.wikipedia.org/wiki/IPv6_address#Local_addresses). If you're interested in global IPv6 connectivity you can use services like [Hurricane Electric](https://www.he.net/) to create an "IPv6 tunnel" (free as of 2024, but requires expertise and a compatible router or host computer to set up)
It's also important to be aware that, as currently implemented by Espressif, there are privacy concerns especially when these devices operate on the global IPv6 network: The device's unique identifier (its EUI-64 or MAC address) is used by default as part of its IPv6 address. This means that the device identity can be tracked across multiple networks by any service it connects to.
### Enable IPv6 networking
Due to the privacy consideration, IPv6 networking is not automatically enabled. Instead, it must be explicitly enabled by a call to `start_dhcp_client` with the `ipv6=True` argument specified:
```python
wifi.start_dhcp_client(ipv6=True)
```
### Check IP addresses
The read-only `addresses` property of the `wifi.radio` object holds all addresses, including IPv4 and IPv6 addresses:
```python
>>> wifi.radio.addresses
('FE80::7EDF:A1FF:FE00:518C', 'FD5F:3F5C:FE50:0:7EDF:A1FF:FE00:518C', '10.0.3.96')
```
The `wifi.radio.dns` servers can be IPv4 or IPv6:
```python
>>> wifi.radio.dns
('FD5F:3F5C:FE50::1',)
>>> wifi.radio.dns = ("1.1.1.1",)
>>> wifi.radio.dns
('1.1.1.1',)
```
### Ping v6 networks
`wifi.radio.ping` accepts v6 addresses and names:
```python
>>> wifi.radio.ping("google.com")
0.043
>>> wifi.radio.ping("ipv6.google.com")
0.048
```
### Create & use IPv6 sockets
Use the address family `socket.AF_INET6`. After the socket is created, use methods like `connect`, `send`, `recfrom_into`, etc just like for IPv4 sockets. This code snippet shows communicating with a private-network NTP server; this IPv6 address will not work on your network:
```python
>>> ntp_addr = ("fd5f:3f5c:fe50::20e", 123)
>>> PACKET_SIZE = 48
>>>
>>> buf = bytearray(PACKET_SIZE)
>>> with socket.socket(socket.AF_INET6, socket.SOCK_DGRAM) as s:
... s.settimeout(1)
... buf[0] = 0b0010_0011
... s.sendto(buf, ntp_addr)
... print(s.recvfrom_into(buf))
... print(buf)
...
48
(48, ('fd5f:3f5c:fe50::20e', 123))
bytearray(b'$\x01\x03\xeb\x00\x00\x00\x00\x00\x00\x00GGPS\x00\xeaA0h\x07s;\xc0\x00\x00\x00\x00\x00\x00\x00\x00\xeaA0n\xeb4\x82-\xeaA0n\xebAU\xb1')
```
# MagTag Google Calendar Event Display
## 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!
Info:
## Step 1) Make an Adafruit account
It's free! Visit [https://accounts.adafruit.com/](https://accounts.adafruit.com/) 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://io.adafruit.com/) 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
![](https://cdn-learn.adafruit.com/assets/assets/000/097/449/medium800/adafruit_products_image.png?1607208628 "My Key" has been replaced with a key-shaped icon!)
You will get a popup with your **Username** and **Key** (In this screenshot, we've covered it with red blocks)
Go to the **settings.toml** file on your **CIRCUITPY** drive (or create one with the text editor with your operating system) and add three lines for `AIO_USERNAME`, `ADAFRUIT_AIO_KEY` and `TIMEZONE` so you get something like the following:
```python
# 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
CIRCUITPY_WIFI_SSID = "your-wifi-ssid"
CIRCUITPY_WIFI_PASSWORD = "your-wifi-password"
ADAFRUIT_AIO_USERNAME = "your-adafruit-io-username"
ADAFRUIT_AIO_KEY = "your-adafruit-io-key"
# Timezone names from http://worldtimeapi.org/timezones
TIMEZONE="America/New_York"
```
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](http://worldtimeapi.org/timezones) to see all the time zones available (even though we do not use Worldtime 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
```python
import ipaddress
import os
import ssl
import wifi
import socketpool
import adafruit_requests
# Get our username, key and desired timezone
ssid = os.getenv("CIRCUITPY_WIFI_SSID")
password = os.getenv("CIRCUITPY_WIFI_PASSWORD")
aio_username = os.getenv("ADAFRUIT_AIO_USERNAME")
aio_key = os.getenv("ADAFRUIT_AIO_KEY")
timezone = os.getenv("TIMEZONE")
TIME_URL = f"https://io.adafruit.com/api/v2/{aio_username}/integrations/time/strftime?x-aio-key={aio_key}&tz={timezone}"
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", ssid)
wifi.radio.connect(ssid, password)
print(f"Connected to {ssid}!")
print("My IP address is", wifi.radio.ipv4_address)
ipv4 = ipaddress.ip_address("8.8.4.4")
print("Ping google.com:", wifi.radio.ping(ipv4), "ms")
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 **settings.toml** and can continue to the next steps!
# MagTag Google Calendar Event Display
## Setup Google Calendar API
Danger: This project's code uses the CircuitPython OAuth Library for authentication with Google services. Due to Google's update to the OAuth "authentication flow", the library became incompatible. As a result, this project does not currently work (but may in the future)!
## Obtain Access Tokens
Google provides a Calendar API which lets you access your Google account's calendar events. Let's start by creating an Application and register it with Google's API console.
Navigate to the [Google API Credentials page](https://console.developers.google.com/apis/credentials).
Click Create Credentials.
From the dropdown, select "OAuth client ID"
Select "TV and Limited Input devices" from the dropdown and give your client a name.
Click "Create".
Copy the Client ID and Client Secret to a text document and save it to your computer's desktop. You'll need these values later.
Next, you'll need to authorize your email address. [This is a new step recently added by Google to increase the security of applications](https://stackoverflow.com/questions/65184355/error-403-access-denied-from-google-authentication-web-api-despite-google-acc).
Navigate to [https://console.cloud.google.com/apis/credentials/consent](https://console.cloud.google.com/apis/credentials/consent) and ensure the same project from before is selected.
Under User Type, select External.
Click Create.
Name the App "MagTag Google Calendar" and use your email address in both email fields.
Click Save and Continue.
Under Scopes, click Save and Continue.
Click Add Users and add the email address belonging to the calendar you are viewing on the MagTag.
Click Save and Continue.
Ensure all the information you entered in the previous steps are correct, then click Save and Continue.
# MagTag Google Calendar Event Display
## Code Setup
Danger: This project's code uses the CircuitPython OAuth Library for authentication with Google services. Due to Google's update to the OAuth "authentication flow", the library became incompatible. As a result, this project does not currently work (but may in the future)!
Before you can use the Google Calendar API to request events on your calendar, you must first authenticate the device with Google's authentication server.
We've handled this authorization "flow" [by creating a CircuitPython library](https://github.com/adafruit/Adafruit_CircuitPython_OAuth2) for Google's implementation of OAuth2.0 and an application to run on your device.
## Secrets File Setup
Open the **settings.toml** file on your CircuitPython device using Mu or your favorite text editor. If you don't have one, copy the generic one below. You're going to edit this file to enter your Google API credentials.
- **Change ** `ADAFRUIT_AIO_USERNAME` to your **Adafruit IO username**
- **Change ** `ADAFRUIT_AIO_KEY` to your **Adafruit IO active key**
- **Change** `timezone` to `"Etc/UTC"`
- **Change** `google_client_id` to **the Google client ID you obtained in the previous step**
- **Change** `google_client_secret` to **the Google client ID you obtained in the previous step**
Your **settings.toml** file should look like this:
```python
# 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
CIRCUITPY_WIFI_SSID="your-wifi-ssid"
CIRCUITPY_WIFI_PASSWORD="your-wifi-password"
ADAFRUIT_AIO_USERNAME="my_username"
ADAFRUIT_AIO_KEY="my_key"
timezone="America/New_York" # http://worldtimeapi.org/timezones
google_client_id="YOUR_GOOGLE_CLIENT_ID"
google_client_secret="YOUR_GOOGLE_CLIENT_SECRET"
```
## Add CircuitPython Code and Project Assets
To use with CircuitPython, you need to first install a few libraries, into the lib folder on your **CIRCUITPY** drive. Then you need to update **code.py** with the example script.
Thankfully, we can do this in one go. In the example below, click the **Download Project Bundle** button below to download the necessary libraries and the **code.py** file in a zip file. Extract the contents of the zip file, open the directory **MagTag\_Google\_Calendar/** and then click on the directory that matches the version of CircuitPython you're using and copy the contents of that directory to your **CIRCUITPY** drive.
Your **CIRCUITPY** drive should now look similar to the following image:
Warning:
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/MagTag/MagTag_Google_Calendar/authenticator.py
## Authenticator Code Usage
On your **CIRCUITPY** drive, rename **authenticator.py** to **code.py. ** Then, open the CircuitPython REPL using Mu or another serial monitor.
Your CircuitPython device should boot into the Google Authenticator code and display a code and URL.
Navigate to the [**Google Device page**](https://www.google.com/device) and **enter the code you see on your device**.
**Click Next**
Select the Google Account you'd like to use with the calendar viewer.
- We are using the `https://www.googleapis.com/auth/calendar.readonly` scope which will gives an application **read-only access to your calendar events**.
Since Google has not formally verified the application you created in the previous step, you'll be greeted with a warning.
- **Click Advanced**
- Then, **Click** the **_Go to {your application name} _link**
Finally, a dialog will appear displaying the application's requested permissions.
**Click Allow.**
You'll be presented with a dialog telling you the device has been authenticated.
After 5 seconds, the CircuitPython REPL should display a `google_access_token` and `google_refresh_token`.
Copy and paste these lines into the **settings.toml** file.
Your **settings.toml** file should look like this:
```python
# 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
CIRCUITPY_WIFI_SSID="your-wifi-ssid"
CIRCUITPY_WIFI_PASSWORD="your-wifi-password"
ADAFRUIT_AIO_USERNAME="my_username"
ADAFRUIT_AIO_KEY="my_key"
timezone="America/New_York" # http://worldtimeapi.org/timezones
google_client_id="YOUR_GOOGLE_CLIENT_ID"
google_client_secret="YOUR_GOOGLE_CLIENT_SECRET"
google_access_token="YOUR_GOOGLE_ACCESS_TOKEN"
google_refresh_token="YOUR_GOOGLE_REFRESH_TOKEN"
```
Now that your device is authorized to make requests to the Google Calendar API, let's use it to fetch calendar events!
# MagTag Google Calendar Event Display
## Code Usage
Danger: This project's code uses the CircuitPython OAuth Library for authentication with Google services. Due to Google's update to the OAuth "authentication flow", the library became incompatible. As a result, this project does not currently work (but may in the future)!
## Code
In the **MagTag\_Google\_Calendar** folder from the previous step, copy **code.py** to your **CIRCUITPY** drive. This should overwrite the authenticator code with the calendar event display code.
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/MagTag/MagTag_Google_Calendar/code.py
You should have the following files on your **CIRCUITPY** drive.
## Set Google Calendar ID
Before using this code with your calendar, you'll need to obtain the Google calendar's unique identifier. Navigate to [the Google Calendar Settings Page](https://calendar.google.com/calendar/u/0/r/settings) and click the calendar you'd like to display on the MagTag.
Before using this code with your calendar, you'll need to obtain the Google calendar's unique identifier.
**Navigate** to [the Google Calendar Settings Page](https://calendar.google.com/calendar/u/0/r/settings) and **click** the calendar you'd like to display on the MagTag.
Scroll down on the page until you see the Calendar ID.
**Copy this value** to your clipboard.
In the **code.py** file, set `CALENDAR_ID` using the calendar ID you obtained above.
`CALENDAR_ID = "YOUR_CALENDAR_ID"`
## Code Usage
Every 15 minutes, the MagTag will attempt to fetch your calendar's latest events and display three of them on the screen.
Once an event finishes and the MagTag refreshes, it will be removed from the display.
## Change the refresh rate
After fetching and displaying calendar events, the MagTag goes into a deep-sleep mode for 15 minutes. Modify the following line in the code to reflect how long the MagTag will enter the deep sleep mode for, in minutes.
```python
# Amount of time to wait between refreshing the calendar, in minutes
REFRESH_TIME = 15
```
More frequent refresh will use more battery life. If you want the refresh to be quite frequent, consider using a USB C power supply (or connection to USB power from a computer or phone charger brick) to have the MagTag powered all the time.
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# MagTag Google Calendar Event Display
## Code Walkthrough
Danger: This project's code uses the CircuitPython OAuth Library for authentication with Google services. Due to Google's update to the OAuth "authentication flow", the library became incompatible. As a result, this project does not currently work (but may in the future)!
The Google Calendar Event Display code uses [the Google Calendar API's Event list endpoint](https://developers.google.com/calendar/v3/reference/events/list) to return events from a specific calendar.
The results from a GET request to this endpoint will look something like the following:
```python
{
"kind": "calendar#events",
"etag": "\"p32c9b6vtqmbes0g\"",
"summary": "Meetings",
"updated": "2021-01-12T15:06:56.911Z",
"timeZone": "America/New_York",
"accessRole": "owner",
"defaultReminders": [],
"nextPageToken": "CigKGjMyajF0bm0xcmwzbDBnbWhmNTNyaW9xb3B2GAEggIDA3tm_zrYXGg0IABIAGJiVm_3Vlu4CIgcIBBC35scP",
"items": [
{
"kind": "calendar#event",
"etag": "\"3219736474490000\"",
"id": "32j1tnm1rl3l0gmhf53rioqopv",
"status": "confirmed",
"htmlLink": "https://www.google.com/calendar/event?eid=MzJqMXRubTFybDNsMGdtaGY1M3Jpb3FvcHYgYWpmb242cGhsN24xZG1wanNkbGV2dHFhMDRAZw",
"created": "2021-01-05T17:35:02.000Z",
"updated": "2021-01-05T17:37:17.245Z",
"summary": "Adafruit Show and Tell",
"creator": {
"email": ""
},
"organizer": {
"email": "@group.calendar.google.com",
"displayName": "Meetings",
"self": true
},
"start": {
"dateTime": "2021-01-06T19:30:00-05:00"
},
"end": {
"dateTime": "2021-01-06T20:00:00-05:00"
},
"iCalUID": "@google.com",
"sequence": 0,
"reminders": {
"useDefault": true
}
}
]
}
```
All events are kept within an `items` array which contains detailed information about each event. The code parses this array for the event's `summary` and the event's `start` `dateTime`.
## Refreshing Google API Access Token
The Google Calendar API access token expires after a specific time interval. If the access token is expired, the refresh token in **settings.toml** is used to POST a request to Google's servers for a new access token.
```python
if (int(time.monotonic()) - access_token_obtained>= google_auth.access_token_expiration):
print("Access token expired, refreshing...")
if not google_auth.refresh_access_token():
raise RuntimeError(
"Unable to refresh access token - has the token been revoked?"
)
access_token_obtained = int(time.monotonic())
```
## Fetching Calendar Events
Prior to calling Google Calendar, a timestamp must be obtained to display the latest events in ascending order. The code calls the Adafruit IO time service to fetch and set the timestamp we'll use for requesting data from Google Calendar.
```python
# fetch calendar events!
print("fetching local time...")
now = get_current_time()
```
We'll display the current date at the top of the MagTag. Passing a `pretty_date` argument formats the [struct\_time](https://circuitpython.readthedocs.io/en/latest/shared-bindings/time/index.html#time.struct_time) timestamp into a human-readable timestamp such as "January 6th, 2021"
```python
# setup header label
magtag.set_text(
format_datetime(now, pretty_date=True), label_header, auto_refresh=False
)
```
We use call `get_calendar_events` with the timestamp to request a list of calendar events in ascending order.
```python
print("fetching calendar events...")
events = get_calendar_events(CALENDAR_ID, MAX_EVENTS, now)
```
Within `get_calendar_events`, we perform a HTTP GET to Google Calendar API's event list endpoint
```python
time_max = get_current_time(time_max=True)
print("Fetching calendar events from {0} to {1}".format(time_min, time_max))
headers = {
"Authorization": "Bearer " + google_auth.access_token,
"Accept": "application/json",
"Content-Length": "0",
}
url = (
"https://www.googleapis.com/calendar/v3/calendars/{0}"
"/events?maxResults={1}&timeMin={2}&timeMax={3}&orderBy=startTime"
"&singleEvents=true".format(calendar_id, max_events, time_min, time_max)
)
resp = magtag.network.requests.get(url, headers=headers)
```
Then, the response is parsed. Each entry in the response's `items` array is parsed and appended to an `items` list. This list is returned as `events`.
```python
resp_json = resp.json()
if "error" in resp_json:
raise RuntimeError("Error:", resp_json)
resp.close()
# parse the 'items' array so we can iterate over it easier
items = []
resp_items = resp_json["items"]
if not resp_items:
print("No events scheduled for today!")
for event in range(0, len(resp_items)):
items.append(resp_items[event])
return items
```
Back in the `while True` loop, the code passes the `event` list to `display_calendar_events`.
```python
print("displaying events")
display_calendar_events(events)
```
`display_calendar_events` iterates through the `resp_events` list. In each iteration, it parses an event's start time and description from the list and generates labels to display the data on the device's screen.
```python
def display_calendar_events(resp_events):
# Display all calendar events
for event_idx in range(len(resp_events)):
event = resp_events[event_idx]
# wrap event name around second line if necessary
event_name = magtag.wrap_nicely(event["summary"], 25)
event_name = "\n".join(event_name[0:2]) # only wrap 2 lines, truncate third..
event_start = event["start"]["dateTime"]
print("-" * 40)
print("Event Description: ", event_name)
print("Event Time:", format_datetime(event_start))
print("-" * 40)
# Generate labels holding event info
magtag.add_text(
text_font=font_event,
text_position=(7, 40 + (event_idx * 35)),
text_color=0x000000,
text=format_datetime(event_start),
)
magtag.add_text(
text_font=font_event,
text_position=(88, 40 + (event_idx * 35)),
text_color=0x000000,
text=event_name,
line_spacing=0.65,
)
```
Finally, the display elements are shown on the screen and the MagTag enters low power mode for `REFRESH_TIME` minutes.
```python
magtag.graphics.display.refresh()
print("Sleeping for %d minutes" % REFRESH_TIME)
magtag.exit_and_deep_sleep(REFRESH_TIME * 60)
```
## Featured Products
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- [MagTag Slideshow](https://learn.adafruit.com/magtag-slideshow.md)
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