Overview
This project is perfect for the book lover in all of us. In this project you will create a clock that tells the time using quotes from books. It'll update every five or so minutes (there are enough quotes to update more often but doing so has the potential to wear out your eInk display). Each time, it will display a quote that has the time highlighted in bold.
The code for this project also has some useful functions for mixing multiple fonts in a relatively seamless text block, so if you're trying to do that check out the code attached.
If you'd like to mount yours like I did in the pictures:
If you would like an acrylic frame:
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Install CircuitPython
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 drive to iterate.
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!
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 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)
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 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 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.
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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.
# SPDX-FileCopyrightText: 2020 Brent Rubell for Adafruit Industries
#
# SPDX-License-Identifier: MIT
import os
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"
print("ESP32-S2 WebClient Test")
print(f"My MAC address: {[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(f"Connecting to {os.getenv('CIRCUITPY_WIFI_SSID')}")
wifi.radio.connect(os.getenv("CIRCUITPY_WIFI_SSID"), os.getenv("CIRCUITPY_WIFI_PASSWORD"))
print(f"Connected to {os.getenv('CIRCUITPY_WIFI_SSID')}")
print(f"My IP address: {wifi.radio.ipv4_address}")
ping_ip = ipaddress.IPv4Address("8.8.8.8")
ping = wifi.radio.ping(ip=ping_ip)
# retry once if timed out
if ping is None:
ping = wifi.radio.ping(ip=ping_ip)
if ping is None:
print("Couldn't ping 'google.com' successfully")
else:
# convert s to ms
print(f"Pinging 'google.com' took: {ping * 1000} ms")
pool = socketpool.SocketPool(wifi.radio)
requests = adafruit_requests.Session(pool, ssl.create_default_context())
print(f"Fetching text from {TEXT_URL}")
response = requests.get(TEXT_URL)
print("-" * 40)
print(response.text)
print("-" * 40)
print(f"Fetching json from {JSON_QUOTES_URL}")
response = requests.get(JSON_QUOTES_URL)
print("-" * 40)
print(response.json())
print("-" * 40)
print()
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)
print("Done")
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.
# SPDX-FileCopyrightText: 2023 Adafruit Industries # # SPDX-License-Identifier: MIT # This is where you store the credentials necessary for your code. # The associated demo only requires WiFi, but you can include any # credentials here, such as Adafruit IO username and key, etc. CIRCUITPY_WIFI_SSID = "your-wifi-ssid" CIRCUITPY_WIFI_PASSWORD = "your-wifi-password"
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 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.
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.
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.
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.
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.
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 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 https url for SSL connectivity.
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.
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.
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. If you're interested in global IPv6 connectivity you can use services like Hurricane Electric 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:
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:
>>> 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:
>>> wifi.radio.dns
('FD5F:3F5C:FE50::1',)
>>> wifi.radio.dns = ("1.1.1.1",)
>>> wifi.radio.dns
('1.1.1.1',)
>>> 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:
>>> 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')
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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!
Step 1) Make an Adafruit account
It's free! Visit 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 and click Sign In to log into IO using your Adafruit account. It's free and fast to join.
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:
# 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 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
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!
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Code the MagTag Quote Clock
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 literary-clock/ and then click on the directory that matches the version of CircuitPython you're using.
Connect your MagTag board to your computer via a known good USB data+power cable. The board should show up as a thumb drive named CIRCUITPY in Explorer or Finder (depending on your operating system). Copy the contents of that directory to your CIRCUITPY drive.
Your CIRCUITPY drive should now look similar to the following image:
# SPDX-FileCopyrightText: 2022 Eva Herrada for Adafruit Industries
# SPDX-License-Identifier: MIT
from os import getenv
import time
import ssl
import gc
import socketpool
import wifi
import adafruit_minimqtt.adafruit_minimqtt as MQTT
from adafruit_io.adafruit_io import IO_MQTT
import adafruit_datetime
import adafruit_display_text
from adafruit_display_text import label
import board
from adafruit_bitmap_font import bitmap_font
import displayio
from adafruit_display_shapes.rect import Rect
# Get WiFi details and Adafruit IO keys, ensure these are setup in settings.toml
# (visit io.adafruit.com if you need to create an account, or if you need your Adafruit IO key.)
ssid = getenv("CIRCUITPY_WIFI_SSID")
password = getenv("CIRCUITPY_WIFI_PASSWORD")
aio_username = getenv("ADAFRUIT_AIO_USERNAME")
aio_key = getenv("ADAFRUIT_AIO_KEY")
if None in [ssid, password, aio_username, aio_key]:
raise RuntimeError(
"WiFi and Adafruit IO settings are kept in settings.toml, "
"please add them there. The settings file must contain "
"'CIRCUITPY_WIFI_SSID', 'CIRCUITPY_WIFI_PASSWORD', "
"'ADAFRUIT_AIO_USERNAME' and 'ADAFRUIT_AIO_KEY' at a minimum."
)
UTC_OFFSET = -4
quotes = {}
with open("quotes.csv", "r", encoding="UTF-8") as F:
for quote_line in F:
split = quote_line.split("|")
quotes[split[0]] = split[1:]
display = board.DISPLAY
splash = displayio.Group()
display.root_group = splash
arial = bitmap_font.load_font("fonts/Arial-12.pcf")
bold = bitmap_font.load_font("fonts/Arial-Bold-12.pcf")
LINE_SPACING = 0.8
HEIGHT = arial.get_bounding_box()[1]
QUOTE_X = 10
QUOTE_Y = 7
rect = Rect(0, 0, 296, 128, fill=0xFFFFFF, outline=0xFFFFFF)
splash.append(rect)
quote = label.Label(
font=arial,
x=QUOTE_X,
y=QUOTE_Y,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(quote)
time_label = label.Label(
font=bold,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(time_label)
time_label_2 = label.Label(
font=bold,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(time_label_2)
after_label = label.Label(
font=arial,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(after_label)
after_label_2 = label.Label(
font=arial,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(after_label_2)
author_label = label.Label(
font=arial, x=QUOTE_X, y=115, color=0x000000, line_spacing=LINE_SPACING
)
splash.append(author_label)
print(f"Connecting to {ssid}")
wifi.radio.connect(ssid, password)
print(f"Connected to {ssid}!")
def get_width(font, text):
return sum(font.get_glyph(ord(c)).shift_x for c in text)
def smart_split(text, font, width):
words = ""
spl = text.split(" ")
for i, word in enumerate(spl):
words += f" {word}"
lwidth = get_width(font, words)
if width + lwidth > 276:
spl[i] = "\n" + spl[i]
text = " ".join(spl)
break
return text
def connected(client): # pylint: disable=unused-argument
io.subscribe_to_time("iso")
def disconnected(client): # pylint: disable=unused-argument
print("Disconnected from Adafruit IO!")
def update_text(hour_min):
quote.text = (
time_label.text
) = time_label_2.text = after_label.text = after_label_2.text = ""
before, time_text, after = quotes[hour_min][0].split("^")
text = adafruit_display_text.wrap_text_to_pixels(before, 276, font=arial)
quote.text = "\n".join(text)
for line in text:
width = get_width(arial, line)
time_text = smart_split(time_text, bold, width)
split_time = time_text.split("\n")
if time_text[0] != "\n":
time_label.x = time_x = QUOTE_X + width
time_label.y = time_y = QUOTE_Y + int((len(text) - 1) * HEIGHT * LINE_SPACING)
time_label.text = split_time[0]
if "\n" in time_text:
time_label_2.x = time_x = QUOTE_X
time_label_2.y = time_y = QUOTE_Y + int(len(text) * HEIGHT * LINE_SPACING)
wrapped = adafruit_display_text.wrap_text_to_pixels(
split_time[1], 276, font=arial
)
time_label_2.text = "\n".join(wrapped)
width = get_width(bold, split_time[-1]) + time_x - QUOTE_X
if after:
after = smart_split(after, arial, width)
split_after = after.split("\n")
if after[0] != "\n":
after_label.x = QUOTE_X + width
after_label.y = time_y
after_label.text = split_after[0]
if "\n" in after:
after_label_2.x = QUOTE_X
after_label_2.y = time_y + int(HEIGHT * LINE_SPACING)
wrapped = adafruit_display_text.wrap_text_to_pixels(
split_after[1], 276, font=arial
)
after_label_2.text = "\n".join(wrapped)
author = f"{quotes[hour_min][2]} - {quotes[hour_min][1]}"
author_label.text = adafruit_display_text.wrap_text_to_pixels(
author, 276, font=arial
)[0]
time.sleep(display.time_to_refresh + 0.1)
display.refresh()
LAST = None
def message(client, feed_id, payload): # pylint: disable=unused-argument
global LAST # pylint: disable=global-statement
timezone = adafruit_datetime.timezone.utc
timezone._offset = adafruit_datetime.timedelta( # pylint: disable=protected-access
seconds=UTC_OFFSET * 3600
)
datetime = adafruit_datetime.datetime.fromisoformat(payload[:-1]).replace(
tzinfo=timezone
)
local_datetime = datetime.tzinfo.fromutc(datetime)
print(local_datetime)
hour_min = f"{local_datetime.hour:02}:{local_datetime.minute:02}"
if local_datetime.minute != LAST:
if hour_min in quotes:
update_text(hour_min)
LAST = local_datetime.minute
gc.collect()
# Create a socket pool
pool = socketpool.SocketPool(wifi.radio)
# Initialize a new MQTT Client object
mqtt_client = MQTT.MQTT(
broker="io.adafruit.com",
port=1883,
username=aio_username,
password=aio_key,
socket_pool=pool,
ssl_context=ssl.create_default_context(),
)
# Initialize an Adafruit IO MQTT Client
io = IO_MQTT(mqtt_client)
# Connect the callback methods defined above to Adafruit IO
io.on_connect = connected
io.on_disconnect = disconnected
io.on_message = message
# Connect to Adafruit IO
print("Connecting to Adafruit IO...")
io.connect()
while True:
try:
io.loop()
except (ValueError, RuntimeError) as e:
print("Failed to get data, retrying\n", e)
wifi.reset()
io.reconnect()
continue
time.sleep(1)
The code starts out by importing all the libraries it needs - quite a lot in this case.
import time import ssl import gc import socketpool import wifi import adafruit_minimqtt.adafruit_minimqtt as MQTT from adafruit_io.adafruit_io import IO_MQTT import adafruit_datetime import adafruit_display_text from adafruit_display_text import label import board from adafruit_bitmap_font import bitmap_font import displayio from adafruit_display_shapes.rect import Rect
Then, it sets the UTC offset - you should modify this to your current local UTC offset (you can find that here: https://www.timeanddate.com/time/zone/timezone/utc).
It then imports the quotes file and starts to set up the display and fonts.
UTC_OFFSET = -4
quotes = {}
with open("quotes.csv", "r", encoding="UTF-8") as F:
for quote_line in F:
split = quote_line.split("|")
quotes[split[0]] = split[1:]
display = board.DISPLAY
splash = displayio.Group()
display.root_group = splash
arial = bitmap_font.load_font("fonts/Arial-12.pcf")
bold = bitmap_font.load_font("fonts/Arial-Bold-12.pcf")
LINE_SPACING = 0.8
HEIGHT = arial.get_bounding_box()[1]
QUOTE_X = 10
QUOTE_Y = 7
Now, the display background and text labels are set up and added to the display group.
rect = Rect(0, 0, 296, 128, fill=0xFFFFFF, outline=0xFFFFFF)
splash.append(rect)
quote = label.Label(
font=arial,
x=QUOTE_X,
y=QUOTE_Y,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(quote)
time_label = label.Label(
font=bold,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(time_label)
time_label_2 = label.Label(
font=bold,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(time_label_2)
after_label = label.Label(
font=arial,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(after_label)
after_label_2 = label.Label(
font=arial,
color=0x000000,
line_spacing=LINE_SPACING,
)
splash.append(after_label_2)
author_label = label.Label(
font=arial, x=QUOTE_X, y=115, color=0x000000, line_spacing=LINE_SPACING
)
splash.append(author_label)
After that, the MagTag attempts to connect to the internet.
# Get WiFi details and Adafruit IO keys, ensure these are setup in settings.toml
# (visit io.adafruit.com if you need to create an account, or if you need your Adafruit IO key.)
ssid = getenv("CIRCUITPY_WIFI_SSID")
password = getenv("CIRCUITPY_WIFI_PASSWORD")
aio_username = getenv("ADAFRUIT_AIO_USERNAME")
aio_key = getenv("ADAFRUIT_AIO_KEY")
if None in [ssid, password, aio_username, aio_key]:
raise RuntimeError(
"WiFi and Adafruit IO settings are kept in settings.toml, "
"please add them there. The settings file must contain "
"'CIRCUITPY_WIFI_SSID', 'CIRCUITPY_WIFI_PASSWORD', "
"'ADAFRUIT_AIO_USERNAME' and 'ADAFRUIT_AIO_KEY' at a minimum."
)
# ...
print(f"Connecting to {ssid}")
wifi.radio.connect(ssid, password)
print(f"Connected to {ssid}!")
At this point, we start defining a few helper functions.
The first one, get_width, is used to get the width of a string, in pixels, when passed the string and the font the string will be displayed in.
The next one, smart_split, is used to tell the code when to wrap a line when it's not the first label being used in a block of text. This is necessary since the code uses multiple fonts (bold and normal Arial 12pt.) in the same text block.
The last two are functions that are run when Adafruit IO is initially connected to - it subscribes the user to the ISO formatted time feed - and when it is disconnected from, respectively.
def get_width(font, text):
return sum(font.get_glyph(ord(c)).shift_x for c in text)
def smart_split(text, font, width):
words = ""
spl = text.split(" ")
for i, word in enumerate(spl):
words += f" {word}"
lwidth = get_width(font, words)
if width + lwidth > 276:
spl[i] = "\n" + spl[i]
text = " ".join(spl)
break
return text
def connected(client): # pylint: disable=unused-argument
io.subscribe_to_time("iso")
def disconnected(client): # pylint: disable=unused-argument
print("Disconnected from Adafruit IO!")
This function is run whenever the quote to be displayed is updated. It's a bit complicated but a very important part of this project.
It starts by wiping all of the labels since we don't use every single label every time.
It then goes on to separate the different parts of the quote so it can set one part of that as bold and the rest as normal and sets the text of the part of the quote prior to the time.
Then the code for setting the location of the time text and the text after the time text is run, which account for the possibility that the first line of that may need to be wrapped over to the next line.
Finally, the display is refreshed with the new quote.
def update_text(hour_min):
quote.text = (
time_label.text
) = time_label_2.text = after_label.text = after_label_2.text = ""
before, time_text, after = quotes[hour_min][0].split("^")
text = adafruit_display_text.wrap_text_to_pixels(before, 276, font=arial)
quote.text = "\n".join(text)
for line in text:
width = get_width(arial, line)
time_text = smart_split(time_text, bold, width)
split_time = time_text.split("\n")
if time_text[0] != "\n":
time_label.x = time_x = QUOTE_X + width
time_label.y = time_y = QUOTE_Y + int((len(text) - 1) * HEIGHT * LINE_SPACING)
time_label.text = split_time[0]
if "\n" in time_text:
time_label_2.x = time_x = QUOTE_X
time_label_2.y = time_y = QUOTE_Y + int(len(text) * HEIGHT * LINE_SPACING)
wrapped = adafruit_display_text.wrap_text_to_pixels(
split_time[1], 276, font=arial
)
time_label_2.text = "\n".join(wrapped)
width = get_width(bold, split_time[-1]) + time_x - QUOTE_X
if after:
after = smart_split(after, arial, width)
split_after = after.split("\n")
if after[0] != "\n":
after_label.x = QUOTE_X + width
after_label.y = time_y
after_label.text = split_after[0]
if "\n" in after:
after_label_2.x = QUOTE_X
after_label_2.y = time_y + int(HEIGHT * LINE_SPACING)
wrapped = adafruit_display_text.wrap_text_to_pixels(
split_after[1], 276, font=arial
)
after_label_2.text = "\n".join(wrapped)
author = f"{quotes[hour_min][2]} - {quotes[hour_min][1]}"
author_label.text = adafruit_display_text.wrap_text_to_pixels(
author, 276, font=arial
)[0]
time.sleep(display.time_to_refresh + 0.1)
display.refresh()
This function is run whenever the IO feed gets a new value, so roughly once a second. It starts by converting the received UTC time into the local time.
Then it checks to see if the time received is the same hour and minute as the last time received and if a quote entry exists for said time. If it isn't the same time and a quote does exist, the code then sends the time to the function above to update the quote.
LAST = None
def message(client, feed_id, payload): # pylint: disable=unused-argument
global LAST # pylint: disable=global-statement
timezone = adafruit_datetime.timezone.utc
timezone._offset = adafruit_datetime.timedelta( # pylint: disable=protected-access
seconds=UTC_OFFSET * 3600
)
datetime = adafruit_datetime.datetime.fromisoformat(payload[:-1]).replace(
tzinfo=timezone
)
local_datetime = datetime.tzinfo.fromutc(datetime)
print(local_datetime)
hour_min = f"{local_datetime.hour:02}:{local_datetime.minute:02}"
if local_datetime.minute != LAST:
if hour_min in quotes:
update_text(hour_min)
LAST = local_datetime.minute
gc.collect()
However, before any of those functions can be used, the code needs to set up the Adafruit IO MQTT connection, which the following code does.
# Create a socket pool
pool = socketpool.SocketPool(wifi.radio)
# Initialize a new MQTT Client object
mqtt_client = MQTT.MQTT(
broker="io.adafruit.com",
port=1883,
username=aio_username,
password=aio_key,
socket_pool=pool,
ssl_context=ssl.create_default_context(),
)
# Initialize an Adafruit IO MQTT Client
io = IO_MQTT(mqtt_client)
# Connect the callback methods defined above to Adafruit IO
io.on_connect = connected
io.on_disconnect = disconnected
io.on_message = message
# Connect to Adafruit IO
print("Connecting to Adafruit IO...")
io.connect()
After it is connected the code runs through this loop to continually check for a new feed update from the Adafruit IO time feed.
while True:
try:
io.loop()
except (ValueError, RuntimeError) as e:
print("Failed to get data, retrying\n", e)
wifi.reset()
io.reconnect()
continue
time.sleep(1)
Page last edited March 08, 2024
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Using The MagTag Quote Clock
If you've already loaded all the code onto the board, all that's left to do is update the UTC offset on line 20 of code.py to reflect your local time. UTC is 4 hours ahead of my local time, so I set my UTC offset to -4.
After that, plug your MagTag into a power source and you should be good to go!
Page last edited March 08, 2024
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