Keep an eye on your schedule with this PyPortal Google Calendar Event Viewer. This CircuitPython project uses the Google Calendar API to retrieve a list of the latest events from your Google Calendar and displays them on the PyPortal's screen.

This guide is almost identical to the MagTag Google Calendar Event Display Guide, except it doesn't have a deep-sleep mode.

Parts

Front view of a Adafruit PyPortal - CircuitPython Powered Internet Display with a pyportal logo image on the display.
PyPortal, our easy-to-use IoT device that allows you to create all the things for the “Internet of Things” in minutes. Make custom touch screen interface...
$54.95
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Assembled PyPortal in acrylic enclosure
PyPortal is our easy-to-use IoT device that allows you to create all the things for the “Internet of Things” in minutes. Create little pocket...
$9.95
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USB cable - USB A to Micro-B - 3 foot long
This here is your standard A to micro-B USB cable, for USB 1.1 or 2.0. Perfect for connecting a PC to your Metro, Feather, Raspberry Pi or other dev-board or...
$2.95
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CircuitPython is a derivative of MicroPython designed to simplify experimentation and education on low-cost microcontrollers. It makes it easier than ever to get prototyping by requiring no upfront desktop software downloads. Simply copy and edit files on the CIRCUITPY "flash" drive to iterate.

The following instructions will show you how to install CircuitPython. If you've already installed CircuitPython but are looking to update it or reinstall it, the same steps work for that as well!

Set up CircuitPython Quick Start!

Follow this quick step-by-step for super-fast Python power :)

Click the link above to download the latest version of CircuitPython for the PyPortal.

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

Plug your PyPortal into your computer using a known-good USB cable.

A lot of people end up using charge-only USB cables and it is very frustrating! So make sure you have a USB cable you know is good for data sync.

Double-click the Reset button on the top in the middle (magenta arrow) on your board, and you will see the NeoPixel RGB LED (green arrow) turn green. If it turns red, check the USB cable, try another USB port, etc. Note: The little red LED next to the USB connector will pulse red. That's ok!

If double-clicking doesn't work the first time, try again. Sometimes it can take a few tries to get the rhythm right!

You will see a new disk drive appear called PORTALBOOT.

Drag the adafruit-circuitpython-pyportal-<whatever>.uf2 file to PORTALBOOT.

The LED will flash. Then, the PORTALBOOT drive will disappear and a new disk drive called CIRCUITPY will appear.

If you haven't added any code to your board, the only file that will be present is boot_out.txt. This is absolutely normal! It's time for you to add your code.py and get started!

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

PyPortal Default Files

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

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

Adafruit CircuitPython Bundle

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

Download the adafruit-circuitpython-bundle-*.x-mpy-*.zip bundle zip file where *.x MATCHES THE VERSION OF CIRCUITPYTHON YOU INSTALLED, and unzip a folder of the same name. Inside you'll find a lib folder. You have two options:

  • You can add the lib folder to your CIRCUITPY drive. This will ensure you have all the drivers. But it will take a bunch of space on the 8 MB disk
  • 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_esp32spi - This is the library that gives you internet access via the ESP32 using (you guessed it!) SPI transport. You need this for anything Internet
  • adafruit_requests - This library allows us to perform HTTP requests and get responses back from servers. GET/POST/PUT/PATCH - they're all in here!
  • adafruit_pyportal - This is our friendly wrapper library that does a lot of our projects, displays graphics and text, fetches data from the internet. Nearly all of our projects depend on it!
  • adafruit_portalbase - This library is the base library that adafruit_pyportal library is built on top of.
  • adafruit_touchscreen - a library for reading touches from the resistive touchscreen. Handles all the analog noodling, rotation and calibration for you.
  • adafruit_io - this library helps connect the PyPortal to our free datalogging and viewing service
  • adafruit_imageload - an image display helper, required for any graphics!
  • adafruit_display_text - not surprisingly, it displays text on the screen
  • adafruit_bitmap_font - we have fancy font support, and its easy to make new fonts. This library reads and parses font files.
  • adafruit_slideshow - for making image slideshows - handy for quick display of graphics and sound
  • neopixel - for controlling the onboard neopixel
  • adafruit_adt7410 - library to read the temperature from the on-board Analog Devices ADT7410 precision temperature sensor (not necessary for Titano or Pynt)
  • adafruit_bus_device - low level support for I2C/SPI
  • adafruit_fakerequests - This library allows you to create fake HTTP requests by using local files.

Once you have CircuitPython setup and libraries installed we can get your board connected to the Internet. Note that access to enterprise level secured WiFi networks is not currently supported, only WiFi networks that require SSID and password.

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

What's a 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 ssid',
    'password' : 'my password',
    'timezone' : "America/New_York", # http://worldtimeapi.org/timezones
    'github_token' : 'fawfj23rakjnfawiefa',
    'hackaday_token' : 'h4xx0rs3kret',
    }

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 the ssid and password for your local WiFi setup. 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 it's 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 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.

Connect to WiFi

OK now you have your secrets setup - you can connect to the Internet. Lets use the ESP32SPI and the Requests libraries - you'll need to visit the CircuitPython bundle and install:

  • adafruit_bus_device
  • adafruit_esp32spi
  • adafruit_requests
  • neopixel

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

# SPDX-FileCopyrightText: 2019 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import board
import busio
from digitalio import DigitalInOut
import adafruit_requests as requests
import adafruit_esp32spi.adafruit_esp32spi_socket as socket
from adafruit_esp32spi import adafruit_esp32spi

# 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 SPI webclient test")

TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html"
JSON_URL = "http://api.coindesk.com/v1/bpi/currentprice/USD.json"


# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an AirLift Shield:
# esp32_cs = DigitalInOut(board.D10)
# esp32_ready = DigitalInOut(board.D7)
# esp32_reset = DigitalInOut(board.D5)

# If you have an AirLift Featherwing or ItsyBitsy Airlift:
# esp32_cs = DigitalInOut(board.D13)
# esp32_ready = DigitalInOut(board.D11)
# esp32_reset = DigitalInOut(board.D12)

# If you have an externally connected ESP32:
# NOTE: You may need to change the pins to reflect your wiring
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

requests.set_socket(socket, esp)

if esp.status == adafruit_esp32spi.WL_IDLE_STATUS:
    print("ESP32 found and in idle mode")
print("Firmware vers.", esp.firmware_version)
print("MAC addr:", [hex(i) for i in esp.MAC_address])

for ap in esp.scan_networks():
    print("\t%s\t\tRSSI: %d" % (str(ap["ssid"], "utf-8"), ap["rssi"]))

print("Connecting to AP...")
while not esp.is_connected:
    try:
        esp.connect_AP(secrets["ssid"], secrets["password"])
    except OSError as e:
        print("could not connect to AP, retrying: ", e)
        continue
print("Connected to", str(esp.ssid, "utf-8"), "\tRSSI:", esp.rssi)
print("My IP address is", esp.pretty_ip(esp.ip_address))
print(
    "IP lookup adafruit.com: %s" % esp.pretty_ip(esp.get_host_by_name("adafruit.com"))
)
print("Ping google.com: %d ms" % esp.ping("google.com"))

# esp._debug = True
print("Fetching text from", TEXT_URL)
r = requests.get(TEXT_URL)
print("-" * 40)
print(r.text)
print("-" * 40)
r.close()

print()
print("Fetching json from", JSON_URL)
r = requests.get(JSON_URL)
print("-" * 40)
print(r.json())
print("-" * 40)
r.close()

print("Done!")

And save it to your board, with the name code.py

Don't forget you'll also need to create the secrets.py file as seen above, with your WiFi ssid and password.

In a serial console, you should see something like the following. For more information about connecting with a serial console, view the guide Connecting to the Serial Console.

In order, the example code...

Initializes the ESP32 over SPI using the SPI port and 3 control pins:

esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

Tells our requests library the type of socket we're using (socket type varies by connectivity type - we'll be using the adafruit_esp32spi_socket for this example). We'll also set the interface to an esp object. This is a little bit of a hack, but it lets us use requests like CPython does.

requests.set_socket(socket, esp)

Verifies an ESP32 is found, checks the firmware and MAC address

if esp.status == adafruit_esp32spi.WL_IDLE_STATUS:
    print("ESP32 found and in idle mode")
print("Firmware vers.", esp.firmware_version)
print("MAC addr:", [hex(i) for i in esp.MAC_address])

Performs a scan of all access points it can see and prints out the name and signal strength:

for ap in esp.scan_networks():
    print("\t%s\t\tRSSI: %d" % (str(ap['ssid'], 'utf-8'), ap['rssi']))

Connects to the AP we've defined here, then prints out the local IP address, attempts to do a domain name lookup and ping google.com to check network connectivity (note sometimes the ping fails or takes a while, this isn't a big deal)

print("Connecting to AP...")
while not esp.is_connected:
    try:
        esp.connect_AP(secrets["ssid"], secrets["password"])
    except RuntimeError as e:
        print("could not connect to AP, retrying: ", e)
        continue
print("Connected to", str(esp.ssid, "utf-8"), "\tRSSI:", esp.rssi)
print("My IP address is", esp.pretty_ip(esp.ip_address))
print(
    "IP lookup adafruit.com: %s" % esp.pretty_ip(esp.get_host_by_name("adafruit.com"))

OK now we're getting to the really interesting part. With a SAMD51 or other large-RAM (well, over 32 KB) device, we can do a lot of neat tricks. Like for example we can implement an interface a lot like requests - which makes getting data really really easy

To read in all the text from a web URL call requests.get - you can pass in https URLs for SSL connectivity

TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html"
print("Fetching text from", TEXT_URL)
r = requests.get(TEXT_URL)
print('-'*40)
print(r.text)
print('-'*40)
r.close()

Or, if the data is in structured JSON, you can get the json pre-parsed into a Python dictionary that can be easily queried or traversed. (Again, only for nRF52840, M4 and other high-RAM boards)

JSON_URL = "http://api.coindesk.com/v1/bpi/currentprice/USD.json"
print("Fetching json from", JSON_URL)
r = requests.get(JSON_URL)
print('-'*40)
print(r.json())
print('-'*40)
r.close()

Requests

We've written a requests-like library for web interfacing named Adafruit_CircuitPython_Requests. This library allows you to send HTTP/1.1 requests without "crafting" them and provides helpful methods for parsing the response from the server.

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

# adafruit_requests usage with an esp32spi_socket
import board
import busio
from digitalio import DigitalInOut
import adafruit_esp32spi.adafruit_esp32spi_socket as socket
from adafruit_esp32spi import adafruit_esp32spi
import adafruit_requests as requests

# Add a secrets.py to your filesystem that has a dictionary called secrets with "ssid" and
# "password" keys with your WiFi credentials. DO NOT share that file or commit it into Git or other
# source control.
# pylint: disable=no-name-in-module,wrong-import-order
try:
    from secrets import secrets
except ImportError:
    print("WiFi secrets are kept in secrets.py, please add them there!")
    raise

# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an externally connected ESP32:
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)

# If you have an AirLift Featherwing or ItsyBitsy Airlift:
# esp32_cs = DigitalInOut(board.D13)
# esp32_ready = DigitalInOut(board.D11)
# esp32_reset = DigitalInOut(board.D12)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

print("Connecting to AP...")
while not esp.is_connected:
    try:
        esp.connect_AP(secrets["ssid"], secrets["password"])
    except RuntimeError as e:
        print("could not connect to AP, retrying: ", e)
        continue
print("Connected to", str(esp.ssid, "utf-8"), "\tRSSI:", esp.rssi)

# Initialize a requests object with a socket and esp32spi interface
socket.set_interface(esp)
requests.set_socket(socket, esp)

TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html"
JSON_GET_URL = "https://httpbin.org/get"
JSON_POST_URL = "https://httpbin.org/post"

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

print("Text Response: ", response.text)
print("-" * 40)
response.close()

print("Fetching JSON data from %s" % JSON_GET_URL)
response = requests.get(JSON_GET_URL)
print("-" * 40)

print("JSON Response: ", response.json())
print("-" * 40)
response.close()

data = "31F"
print("POSTing data to {0}: {1}".format(JSON_POST_URL, data))
response = requests.post(JSON_POST_URL, data=data)
print("-" * 40)

json_resp = response.json()
# Parse out the 'data' key from json_resp dict.
print("Data received from server:", json_resp["data"])
print("-" * 40)
response.close()

json_data = {"Date": "July 25, 2019"}
print("POSTing data to {0}: {1}".format(JSON_POST_URL, json_data))
response = requests.post(JSON_POST_URL, json=json_data)
print("-" * 40)

json_resp = response.json()
# Parse out the 'json' key from json_resp dict.
print("JSON Data received from server:", json_resp["json"])
print("-" * 40)
response.close()

The code first sets up the ESP32SPI interface. Then, it initializes a request object using an ESP32 socket and the esp object.

import board
import busio
from digitalio import DigitalInOut
import adafruit_esp32spi.adafruit_esp32spi_socket as socket
from adafruit_esp32spi import adafruit_esp32spi
import adafruit_requests as requests

# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an externally connected ESP32:
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

print("Connecting to AP...")
while not esp.is_connected:
    try:
        esp.connect_AP(b'MY_SSID_NAME', b'MY_SSID_PASSWORD')
    except RuntimeError as e:
        print("could not connect to AP, retrying: ",e)
        continue
print("Connected to", str(esp.ssid, 'utf-8'), "\tRSSI:", esp.rssi)

# Initialize a requests object with a socket and esp32spi interface
requests.set_socket(socket, esp)

HTTP GET with Requests

The code makes a HTTP GET request to Adafruit's WiFi testing website - http://wifitest.adafruit.com/testwifi/index.html.

To do this, we'll pass the URL into requests.get(). We're also going to save the response from the server into a variable named response.

Having requested data from the server, we'd now like to see what the server responded with. Since we already saved the server's response, we can read it back. Luckily for us, requests automatically decodes the server's response into human-readable text, you can read it back by calling response.text.

Lastly, we'll perform a bit of cleanup by calling response.close(). This closes, deletes, and collect's the response's data. 

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

print("Text Response: ", response.text)
print('-'*40)
response.close()

While some servers respond with text, some respond with json-formatted data consisting of attribute–value pairs.

CircuitPython_Requests can convert a JSON-formatted response from a server into a CPython dict. object.

We can also fetch and parse json data. We'll send a HTTP get to a url we know returns a json-formatted response (instead of text data). 

Then, the code calls response.json() to convert the response to a CPython dict

print("Fetching JSON data from %s"%JSON_GET_URL)
response = requests.get(JSON_GET_URL)
print('-'*40)

print("JSON Response: ", response.json())
print('-'*40)
response.close()

HTTP POST with Requests

Requests can also POST data to a server by calling the requests.post method, passing it a data value.

data = '31F'
print("POSTing data to {0}: {1}".format(JSON_POST_URL, data))
response = requests.post(JSON_POST_URL, data=data)
print('-'*40)

json_resp = response.json()
# Parse out the 'data' key from json_resp dict.
print("Data received from server:", json_resp['data'])
print('-'*40)
response.close()

You can also post json-formatted data to a server by passing json_data into the requests.post method.

    json_data = {"Date" : "July 25, 2019"}
print("POSTing data to {0}: {1}".format(JSON_POST_URL, json_data))
response = requests.post(JSON_POST_URL, json=json_data)
print('-'*40)

json_resp = response.json()
# Parse out the 'json' key from json_resp dict.
print("JSON Data received from server:", json_resp['json'])
print('-'*40)
response.close()
  

Advanced Requests Usage

Want to send custom HTTP headers, parse the response as raw bytes, or handle a response's http status code in your CircuitPython code?

We've written an example to show advanced usage of the requests module below.

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import board
import busio
from digitalio import DigitalInOut
import adafruit_esp32spi.adafruit_esp32spi_socket as socket
from adafruit_esp32spi import adafruit_esp32spi
import adafruit_requests as requests

# Add a secrets.py to your filesystem that has a dictionary called secrets with "ssid" and
# "password" keys with your WiFi credentials. DO NOT share that file or commit it into Git or other
# source control.
# pylint: disable=no-name-in-module,wrong-import-order
try:
    from secrets import secrets
except ImportError:
    print("WiFi secrets are kept in secrets.py, please add them there!")
    raise

# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an externally connected ESP32:
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

print("Connecting to AP...")
while not esp.is_connected:
    try:
        esp.connect_AP(secrets["ssid"], secrets["password"])
    except RuntimeError as e:
        print("could not connect to AP, retrying: ", e)
        continue
print("Connected to", str(esp.ssid, "utf-8"), "\tRSSI:", esp.rssi)

# Initialize a requests object with a socket and esp32spi interface
socket.set_interface(esp)
requests.set_socket(socket, esp)

JSON_GET_URL = "http://httpbin.org/get"

# Define a custom header as a dict.
headers = {"user-agent": "blinka/1.0.0"}

print("Fetching JSON data from %s..." % JSON_GET_URL)
response = requests.get(JSON_GET_URL, headers=headers)
print("-" * 60)

json_data = response.json()
headers = json_data["headers"]
print("Response's Custom User-Agent Header: {0}".format(headers["User-Agent"]))
print("-" * 60)

# Read Response's HTTP status code
print("Response HTTP Status Code: ", response.status_code)
print("-" * 60)

# Close, delete and collect the response data
response.close()

WiFi Manager

That simpletest example works but it's a little finicky - you need to constantly check WiFi status and have many loops to manage connections and disconnections. For more advanced uses, we recommend using the WiFiManager object. It will wrap the connection/status/requests loop for you - reconnecting if WiFi drops, resetting the ESP32 if it gets into a bad state, etc.

Here's a more advanced example that shows the WiFi manager and also how to POST data with some extra headers:

# SPDX-FileCopyrightText: 2019 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import time
import board
import busio
from digitalio import DigitalInOut
import neopixel
from adafruit_esp32spi import adafruit_esp32spi
from adafruit_esp32spi import adafruit_esp32spi_wifimanager

print("ESP32 SPI webclient test")

# 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

# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an externally connected ESP32:
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
"""Use below for Most Boards"""
status_light = neopixel.NeoPixel(
    board.NEOPIXEL, 1, brightness=0.2
)  # Uncomment for Most Boards
"""Uncomment below for ItsyBitsy M4"""
# status_light = dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1, brightness=0.2)
# Uncomment below for an externally defined RGB LED
# import adafruit_rgbled
# from adafruit_esp32spi import PWMOut
# RED_LED = PWMOut.PWMOut(esp, 26)
# GREEN_LED = PWMOut.PWMOut(esp, 27)
# BLUE_LED = PWMOut.PWMOut(esp, 25)
# status_light = adafruit_rgbled.RGBLED(RED_LED, BLUE_LED, GREEN_LED)
wifi = adafruit_esp32spi_wifimanager.ESPSPI_WiFiManager(esp, secrets, status_light)

counter = 0

while True:
    try:
        print("Posting data...", end="")
        data = counter
        feed = "test"
        payload = {"value": data}
        response = wifi.post(
            "https://io.adafruit.com/api/v2/"
            + secrets["aio_username"]
            + "/feeds/"
            + feed
            + "/data",
            json=payload,
            headers={"X-AIO-KEY": secrets["aio_key"]},
        )
        print(response.json())
        response.close()
        counter = counter + 1
        print("OK")
    except OSError as e:
        print("Failed to get data, retrying\n", e)
        wifi.reset()
        continue
    response = None
    time.sleep(15)

You'll note here we use a secrets.py file to manage our SSID info. The wifimanager is given the ESP32 object, secrets and a neopixel for status indication.

Note, you'll need to add a some additional information to your secrets file so that the code can query the Adafruit IO API:

  • aio_username
  • aio_key

You can go to your adafruit.io View AIO Key link to get those two values and add them to the secrets file, which will now look something 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' : '_your_ssid_',
    'password' : '_your_wifi_password_',
    'timezone' : "America/Los_Angeles", # http://worldtimeapi.org/timezones
    'aio_username' : '_your_aio_username_',
    'aio_key' : '_your_aio_key_',
    }

Next, set up an Adafruit IO feed named test

We can then have a simple loop for posting data to Adafruit IO without having to deal with connecting or initializing the hardware!

Take a look at your test feed on Adafruit.io and you'll see the value increase each time the CircuitPython board posts data to it!

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

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.

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 for Google's implementation of OAuth2.0 and an application to run on your device.

Secrets File Setup

Open the secrets.py file on your CircuitPython device using Mu or your favorite text editor. If you don't have a secrets.py file yet, copy the template below. You're going to edit this file to enter your Google API credentials.

  • Change aio_username to your Adafruit IO username
  • Change 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 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' : 'YOUR_SSID',
    'password' : 'YOUR_SSID_PASS',
    'aio_username': 'YOUR_AIO_USERNAME',
    'aio_key': 'YOUR_AIO_KEY'
    'timezone' : "Etc/UTC", # http://worldtimeapi.org/timezones
    'google_client_id' : 'YOUR_GOOGLE_CLIENT_ID',
    'google_client_secret' : 'YOUR_GOOGLE_CLIENT_SECRET'
    }

Add CircuitPython Code and Project Assets

In the embedded code element below, click on the Download: Project Zip link, and save the .zip archive file to your computer.

Then, uncompress the .zip file, it will unpack to a folder named PyPortal_Google_Calendar

Copy the contents of the PyPortal_Google_Calendar directory to your PyPortal's CIRCUITPY drive.

# SPDX-FileCopyrightText: 2021 Brent Rubell, written for Adafruit Industries
#
# SPDX-License-Identifier: Unlicense
from adafruit_display_text.label import Label
from adafruit_bitmap_font import bitmap_font
from adafruit_oauth2 import OAuth2
from adafruit_pyportal import Network, Graphics

# Add a secrets.py to your filesystem that has a dictionary called secrets with "ssid" and
# "password" keys with your WiFi credentials. DO NOT share that file or commit it into Git or other
# source control.
# pylint: disable=no-name-in-module,wrong-import-order
try:
    from secrets import secrets
except ImportError:
    print("WiFi secrets are kept in secrets.py, please add them there!")
    raise

network = Network()
network.connect()

graphics = Graphics()

# DisplayIO Setup
# Set up fonts
font_small = bitmap_font.load_font("/fonts/Arial-12.pcf")
font_large = bitmap_font.load_font("/fonts/Arial-14.pcf")
# preload fonts
glyphs = b"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-,.: "
font_small.load_glyphs(glyphs)
font_large.load_glyphs(glyphs)

label_overview_text = Label(
    font_large, x=0, y=45, text="To authorize this device with Google:"
)
graphics.splash.append(label_overview_text)

label_verification_url = Label(font_small, x=0, y=100, line_spacing=1)
graphics.splash.append(label_verification_url)

label_user_code = Label(font_small, x=0, y=150)
graphics.splash.append(label_user_code)

label_qr_code = Label(font_small, x=0, y=190, text="Or scan the QR code:")
graphics.splash.append(label_qr_code)

# Set scope(s) of access required by the API you're using
scopes = ["https://www.googleapis.com/auth/calendar.readonly"]

# Initialize an oauth2 object
google_auth = OAuth2(
    network.requests,
    secrets["google_client_id"],
    secrets["google_client_secret"],
    scopes,
)

# Request device and user codes
# https://developers.google.com/identity/protocols/oauth2/limited-input-device#step-1:-request-device-and-user-codes
google_auth.request_codes()

# Display user code and verification url
# NOTE: If you are displaying this on a screen, ensure the text label fields are
# long enough to handle the user_code and verification_url.
# Details in link below:
# https://developers.google.com/identity/protocols/oauth2/limited-input-device#displayingthecode
print(
    "1) Navigate to the following URL in a web browser:", google_auth.verification_url
)
print("2) Enter the following code:", google_auth.user_code)

# modify display labels to show verification URL and user code
label_verification_url.text = (
    "1. On your computer or mobile device,\n    go to: %s"
    % google_auth.verification_url
)
label_user_code.text = "2. Enter code: %s" % google_auth.user_code

# Create a QR code
graphics.qrcode(google_auth.verification_url.encode(), qr_size=2, x=170, y=165)
graphics.display.show(graphics.splash)

# Poll Google's authorization server
print("Waiting for browser authorization...")
if not google_auth.wait_for_authorization():
    raise RuntimeError("Timed out waiting for browser response!")

print("Successfully Authenticated with Google!")

# print formatted keys for adding to secrets.py
print("Add the following lines to your secrets.py file:")
print("\t'google_access_token' " + ":" + " '%s'," % google_auth.access_token)
print("\t'google_refresh_token' " + ":" + " '%s'" % google_auth.refresh_token)
# Remove QR code and code/verification labels
graphics.splash.pop()
graphics.splash.pop()
graphics.splash.pop()

label_overview_text.text = "Successfully Authenticated!"
label_verification_url.text = (
    "Check the REPL for tokens to add\n\tto your secrets.py file"
)

# prevent exit
while True:
    pass

Once all the files are copied from your computer to the CircuitPython device, you should have the following files on your CIRCUITPY drive.

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 PyPortal should boot into the Google Authenticator code and display a code and URL.

Navigate to the Google Device page and enter the code you see on your device.

Click Next

Select the Google Account you'd like to use with the calendar viewer.

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 secrets.py file.

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' : 'YOUR_SSID',
    'password' : 'YOUR_SSID_PASS',
    'aio_username': 'YOUR_AIO_USERNAME',
    'aio_key': 'YOUR_AIO_KEY'
    'timezone' : "Etc/UTC", # 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!

Code

In the PyPortal_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.

# SPDX-FileCopyrightText: 2021 Brent Rubell, written for Adafruit Industries
#
# SPDX-License-Identifier: Unlicense
import time
from adafruit_oauth2 import OAuth2
from adafruit_display_shapes.line import Line
from adafruit_pyportal import PyPortal
import rtc

# Calendar ID
CALENDAR_ID = "YOUR_CAL_ID"

# Maximum amount of events to display
MAX_EVENTS = 5

# Amount of time to wait between refreshing the calendar, in minutes
REFRESH_TIME = 15

MONTHS = {
    1: "Jan",
    2: "Feb",
    3: "Mar",
    4: "Apr",
    5: "May",
    6: "Jun",
    7: "Jul",
    8: "Aug",
    9: "Sep",
    10: "Oct",
    11: "Nov",
    12: "Dec",
}

# Dict. of day names for pretty-printing the header
WEEKDAYS = {
    0: "Monday",
    1: "Tuesday",
    2: "Wednesday",
    3: "Thursday",
    4: "Friday",
    5: "Saturday",
    6: "Sunday",
}

# Add a secrets.py to your filesystem that has a dictionary called secrets with "ssid" and
# "password" keys with your WiFi credentials. DO NOT share that file or commit it into Git or other
# source control.
# pylint: disable=no-name-in-module,wrong-import-order
try:
    from secrets import secrets
except ImportError:
    print("WiFi secrets are kept in secrets.py, please add them there!")
    raise

# Create the PyPortal object
pyportal = PyPortal()
r = rtc.RTC()

pyportal.network.connect()


# Initialize an OAuth2 object with GCal API scope
scopes = ["https://www.googleapis.com/auth/calendar.readonly"]
google_auth = OAuth2(
    pyportal.network.requests,
    secrets["google_client_id"],
    secrets["google_client_secret"],
    scopes,
    secrets["google_access_token"],
    secrets["google_refresh_token"],
)


def get_current_time(time_max=False):
    """Gets local time from Adafruit IO and converts to RFC3339 timestamp."""
    # Get local time from Adafruit IO
    pyportal.get_local_time(secrets["timezone"])
    # Format as RFC339 timestamp
    cur_time = r.datetime
    if time_max:  # maximum time to fetch events is midnight (4:59:59UTC)
        cur_time_max = time.struct_time(
            (
                cur_time[0],
                cur_time[1],
                cur_time[2] + 1,
                4,
                59,
                59,
                cur_time[6],
                cur_time[7],
                cur_time[8],
            )
        )
        cur_time = cur_time_max
    cur_time = "{:04d}-{:02d}-{:02d}T{:02d}:{:02d}:{:02d}{:s}".format(
        cur_time[0],
        cur_time[1],
        cur_time[2],
        cur_time[3],
        cur_time[4],
        cur_time[5],
        "Z",
    )
    return cur_time


def get_calendar_events(calendar_id, max_events, time_min):
    """Returns events on a specified calendar.
    Response is a list of events ordered by their start date/time in ascending order.
    """
    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 = pyportal.network.requests.get(url, headers=headers)
    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


def format_datetime(datetime, pretty_date=False):
    """Formats ISO-formatted datetime returned by Google Calendar API into
    a struct_time.
    :param str datetime: Datetime string returned by Google Calendar API
    :return: struct_time

    """
    times = datetime.split("T")
    the_date = times[0]
    the_time = times[1]
    year, month, mday = [int(x) for x in the_date.split("-")]
    the_time = the_time.split("-")[0]
    if "Z" in the_time:
        the_time = the_time.split("Z")[0]
    hours, minutes, _ = [int(x) for x in the_time.split(":")]
    am_pm = "am"
    if hours >= 12:
        am_pm = "pm"
        # convert to 12hr time
        hours -= 12
    # via https://github.com/micropython/micropython/issues/3087
    formatted_time = "{:01d}:{:02d}{:s}".format(hours, minutes, am_pm)
    if pretty_date:  # return a nice date for header label
        formatted_date = "{} {}.{:02d}, {:04d} ".format(
            WEEKDAYS[r.datetime[6]], MONTHS[month], mday, year
        )
        return formatted_date
    # Event occurs today, return the time only
    return formatted_time


def create_event_labels():
    for event_idx in range(MAX_EVENTS):
        event_start_label = pyportal.add_text(
            text_font=font_events,
            text_position=(7, 70 + (event_idx * 40)),
            text_color=0x000000,
        )
        event_text_label = pyportal.add_text(
            text_font=font_events,
            text_position=(88, 70 + (event_idx * 40)),
            text_color=0x000000,
            line_spacing=0.75,
        )
        event_labels.append((event_start_label, event_text_label))


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 = PyPortal.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)
        pyportal.set_text(format_datetime(event_start), event_labels[event_idx][0])
        pyportal.set_text(event_name, event_labels[event_idx][1])

    # Clear any unused labels
    for event_idx in range(len(resp_events), MAX_EVENTS):
        pyportal.set_text("", event_labels[event_idx][0])
        pyportal.set_text("", event_labels[event_idx][1])


pyportal.set_background(0xFFFFFF)

# Set up calendar event fonts
font_events = "fonts/Arial-14.pcf"

# Add the header
line_header = Line(0, 50, 320, 50, color=0x000000)
pyportal.splash.append(line_header)

label_header = pyportal.add_text(
    text_font="fonts/Arial-18.pcf",
    text_position=(10, 30),
    text_color=0x000000,
)
event_labels = []
create_event_labels()

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())

events = []
while True:
    # check if we need to refresh token
    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())

    # fetch calendar events!
    print("fetching local time...")
    now = get_current_time()

    # setup header label
    pyportal.set_text(format_datetime(now, pretty_date=True), label_header)

    print("fetching calendar events...")
    events = get_calendar_events(CALENDAR_ID, MAX_EVENTS, now)

    print("displaying events")
    display_calendar_events(events)

    print("Sleeping for %d minutes" % REFRESH_TIME)
    time.sleep(REFRESH_TIME * 60)

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 and click the calendar you'd like to display on the PyPortal.

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 and click the calendar you'd like to display on the PyPortal.

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 PyPortal will attempt to fetch your calendar's latest events and display three of them on the screen. 

Once an event finishes and the PyPortal refreshes, it will be removed from the display.

Change the refresh rate

After fetching and displaying calendar events, the waits for 15 minutes. Modify the following line in the code to reflect how long the PyPortal will wait between refreshing the calendar events, in minutes.

# Amount of time to wait between refreshing the calendar, in minutes
REFRESH_TIME = 15

The Google Calendar Event Display code uses the Google Calendar API's Event list endpoint to return events from a specific calendar.

The results from a GET request to this endpoint will look something like the following:

{
 "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 secrets.py is used to POST a request to Google's servers for a new access token.

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.

# fetch calendar events!
print("fetching local time...")
now = get_current_time()

We'll display the current date at the top of the PyPortal. Passing a pretty_date argument formats the struct_time timestamp into a human-readable timestamp such as "January 6th, 2021"

# setup header label
pyportal.set_text(format_datetime(now, pretty_date=True), label_header)

Within get_calendar_events, we perform a HTTP GET to Google Calendar API's event list endpoint

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 = PyPortal.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)
        pyportal.set_text(format_datetime(event_start), event_labels[event_idx][0])
        pyportal.set_text(event_name, event_labels[event_idx][1])

    # Clear any unused labels
    for event_idx in range(len(resp_events), MAX_EVENTS):
        pyportal.set_text("", event_labels[event_idx][0])
        pyportal.set_text("", event_labels[event_idx][1])

Finally, the display elements are displayed on the screen and the PyPortal sleeps for REFRESH_TIME minutes.

print("displaying events")
display_calendar_events(events)

print("Sleeping for %d minutes" % REFRESH_TIME)
time.sleep(REFRESH_TIME * 60)

This guide was first published on Jan 13, 2021. It was last updated on Jan 13, 2021.