MagTag Daily Christmas Countdown

2021-12-21 | By Adafruit Industries

License: See Original Project 3D Printing

Courtesy of Adafruit

Guide by Ruiz Brothers

Overview

IoT Holiday Countdown

In this project, make a Christmas countdown using Adafruit’s MagTag. This grabs the date from the internet and updates each day, so you know how many days until Christmas. The little bobbles on the tree are filled in as the days go by so you can quickly see how many days are left.

3D Printed Stand

The stand is designed to be festive and comes in two version: Portrait and Landscape.

You may use two M3 screws to secure the MagTag to the stand, it's easy peasy!

Parts

• Adafruit MagTag - 2.9" Grayscale E-Ink WiFi Display

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

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.

Set Up CircuitPython

Follow the steps to get CircuitPython installed on your MagTag.

Download the latest CircuitPython for your board from circuitpython.org

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

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

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

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

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

Option 1 - Load with UF2 Bootloader

This is by far the easiest way to load CircuitPython. However, it requires your board has the UF2 bootloader installed. Some early boards do not (we hadn't written UF2 yet!) - in which case you can load using the built in ROM bootloader.

Still, try this first!

Try Launching UF2 Bootloader

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

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

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

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

If you're using Windows and you get an error at the end of the file copy that says Error from the file copy, Error 0x800701B1: A device which does not exist was specified. You can ignore this error, the bootloader sometimes disconnects without telling Windows, the install completed just fine and you can continue. If its really annoying, you can also upgrade the bootloader (the latest version of the UF2 bootloader fixes this warning.)

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.

CircuitPython Internet Libraries

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

Adafruit CircuitPython Library Bundle

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

Download latest CircuitPython Library Bundle

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

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

• adafruit_requests.mpy - A requests-like library for HTTP commands

• neopixel.mpy - Helper library to use NeoPixel LEDs, often built into the boards so they're great for quick feedback

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

CircuitPython Internet Test

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

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

Secrets File

We expect people to share tons of projects as they build CircuitPython Wi-Fi 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:

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

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

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

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

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

As you make projects you may need more tokens and keys, just add them one line at a time. See for example other tokens such as one for accessing github or the hackaday API. Other non-secret data like your timezone can also go here, just cause 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.

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

Connect to Wi-Fi

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

First make sure you are running the latest version of Adafruit CircuitPython for your board.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle. Our introduction guide has a great page on how to install the library bundle.

• adafruit_requests

• neopixel

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

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

Download Project Bundle

import ipaddress
import ssl
import wifi
import socketpool
import adafruit_requests

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

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

print("ESP32-S2 WebClient Test")

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

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

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

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

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

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

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

print()

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

print("done")

View on GitHub

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

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

In order, the example code...

Checks the ESP32-S2's MAC address.

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

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

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

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

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

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

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

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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.

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

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

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

Finally, you can fetch and parse a JSON URL using requests.get. This code snippet obtains the stargazers_count field from a call to the GitHub API.

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

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

Getting the Date & Time

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

Determining the correct local time is really really hard. There are various time zones, Daylight Savings dates, leap seconds, etc. Trying to get NTP time and then back-calculating what the local time is, is extraordinarily hard on a microcontroller just isn't worth the effort and it will get out of sync as laws change anyways.

For that reason, we have the free adafruit.io time service. Free for anyone, with a free adafruit.io account. You do need an account because we have to keep accidentally mis-programmed-board from overwhelming adafruit.io and lock them out temporarily. Again, it's free!

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

Step 1) Make an Adafruit account

It's free! Visit https://accounts.adafruit.com/ 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.

Step 3) Get your Adafruit IO Key

Click on My Key in the top bar.

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

Go to your secrets.py file on your CIRCUITPY drive and add three lines for aio_username, aio_key, and timezone so you get something like the following:

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

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

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

Step 4) Upload Test Python Code

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

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


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

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

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

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

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

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

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

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

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

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

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

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

MagTag-Specific CircuitPython Libraries

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

Get Latest Adafruit CircuitPython Bundle

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

Download the latest Library Bundle from circuitpython.org

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

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

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

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

• adafruit_portalbase - This library is the base library that adafruit_magtag is built on top of

• adafruit_bitmap_font - There is fancy font support, and it's easy to make new fonts. This library reads and parses font files

• adafruit_display_text - This library displays text on the screen

• adafruit_io - This library helps connect the MagTag to our free data logging and viewing service

Library files:

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

• adafruit_fakerequests.mpy - This library allows you to create fake HTTP requests by using local files

• adafruit_miniqr.mpy - QR creation library lets us add easy-to-scan 2D barcodes to the E-Ink display

• neopixel.mpy - This library is used to control the onboard NeoPixels

• simpleio.mpy - This library is used for tone generation

Secrets

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

Coding the MagTag Christmas Countdown

Once you've finished setting up your MagTag with CircuitPython, you can add the libraries to the lib folder of the MagTag's CIRCUITPY drive which should appear when the board is plugged into your computer via USB. Copy these folders:

• adafruit_bitmap_font

• adafruit_display_shapes

• adafruit_display_text

• adafruit_io

• adafruit_magtag

• adafruit_portalbase

And these files:

• adafruit_fakerequests.mpy

• adafruit_miniqr.mpy

• adafruit_requests.mpy

• neopixel.mpy

• simpleio.mpy

To the CIRCUITPY flash drive /lib directory (create the directory if it doesn't exist).

Then, you can click on the Download: Project Zip link in the window below to download the code file and bitmap image file.

Download Project Bundle

import time
import displayio
from adafruit_magtag.magtag import MagTag
from adafruit_display_shapes.circle import Circle

#  create MagTag and connect to network
try:
    magtag = MagTag()
    magtag.network.connect()
except (ConnectionError, ValueError, RuntimeError) as e:
    print("*** MagTag(), Some error occured, retrying! -", e)
    # Exit program and restart in 1 seconds.
    magtag.exit_and_deep_sleep(1)



#  displayio groups
group = displayio.Group()
tree_group = displayio.Group()
circle_group = displayio.Group()

#  import tree bitmap
filename = "/atree.bmp"

# CircuitPython 6 & 7 compatible
tree = displayio.OnDiskBitmap(open(filename, "rb"))
tree_grid = displayio.TileGrid(
    tree, pixel_shader=getattr(tree, 'pixel_shader', displayio.ColorConverter())
)

# # CircuitPython 7+ compatible
# tree = displayio.OnDiskBitmap(filename)
# tree_grid = displayio.TileGrid(tree, pixel_shader=tree.pixel_shader)

#  add bitmap to its group
tree_group.append(tree_grid)
#  add tree group to the main group
group.append(tree_group)

#  list of circle positions
spots = (
    (246, 53),
    (246, 75),
    (206, 42),
    (206, 64),
    (206, 86),
    (176, 31),
    (176, 53),
    (176, 75),
    (176, 97),
    (136, 42),
    (136, 64),
    (136, 86),
    (106, 31),
    (106, 53),
    (106, 75),
    (106, 97),
    (66, 31),
    (66, 53),
    (66, 75),
    (66, 97),
    (36, 20),
    (36, 42),
    (36, 64),
    (36, 86),
    (36, 108)
    )

#  circles to cover-up bitmap's number ornaments

ball_color = [0x555555, 0xaaaaaa, 0xFFFFFF] # All colors except black (0x000000)
ball_index = 0

#  creating the circles & pulling in positions from spots
for spot in spots:
    circle = Circle(x0=spot[0], y0=spot[1], r=11, fill=ball_color[ball_index]) # Each ball has a color
    ball_index += 1
    ball_index %= len(ball_color)

	#  adding circles to their display group
    circle_group.append(circle)

#  adding circles group to main display group
group.append(circle_group)

#  grabs time from network
magtag.get_local_time()
#  parses time into month, date, etc
now = time.localtime()
month = now[1]
day = now[2]
(hour, minutes, seconds) = now[3:6]
seconds_since_midnight = 60 * (hour*60 + minutes)+seconds
print( f"day is {day}, ({seconds_since_midnight} seconds since midnight)")


#  sets colors of circles to transparent to reveal dates that have passed & current date
for i in range(day):
    circle_group[i].fill = None
    time.sleep(0.1)

#  updates display with bitmap and current circle colors
magtag.display.show(group)
magtag.display.refresh()
time.sleep(5)

#  goes into deep sleep till a 'stroke' past midnight
print("entering deep sleep")
seconds_to_sleep = 24*60*60 - seconds_since_midnight + 10
print( f"sleeping for {seconds_to_sleep} seconds")
magtag.exit_and_deep_sleep(seconds_to_sleep)

#  entire code will run again after deep sleep cycle
#  similar to hitting the reset button

View on GitHub

Bitmap File

Copy atree.bmp from within the zip file downloaded in the last step to the CIRCUITPY main (root) directory.

Review

Make sure you've followed these steps:

• Created a secrets.py file with your network Wi-Fi info and Adafruit IO info and copied the file to the CIRCUITPY main (root) directory

• Loaded all the required library files and directories into the CIRCUITPY /lib directory

• Copied atree.bmp to the main (root) directory of the CIRCUITPY drive

• Copied code.py to the main (root) directory of the CIRCUITPY drive

Your MagTag CIRCUITPY drive should look like this after you load the libraries, code.py file, secrets.py file and bitmap image file:

CircuitPython Code Walkthrough

The code begins by importing the libraries.

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import time
import displayio
from adafruit_magtag.magtag import MagTag
from adafruit_display_shapes.circle import Circle

A magtag object is created to access the adafruit_magtag library. Your MagTag connects to your network with magtag.network.connect().

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#  create MagTag and connect to network
magtag = MagTag()
magtag.network.connect()

Three displayio groups are used. tree_group holds the tree bitmap image. circle_group holds the circles that will either hide or show the numbers on the tree bitmap. group is the main group that will allow for tree_group and circle_group to be shown at the same time.

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#  displayio groups
group = displayio.Group()
tree_group = displayio.Group()
circle_group = displayio.Group()

The tree bitmap is brought in and added to the tree_group. tree_group is added to group.

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# import tree bitmap
filename = "/atree.bmp"

# CircuitPython 6 & 7 compatible
tree = displayio.OnDiskBitmap(open(filename, "rb"))
tree_grid = displayio.TileGrid(
    tree, pixel_shader=getattr(tree, 'pixel_shader', displayio.ColorConverter())
)

# # CircuitPython 7+ compatible
# tree = displayio.OnDiskBitmap(filename)
# tree_grid = displayio.TileGrid(tree, pixel_shader=tree.pixel_shader)

Each circle has a specific coordinate that corresponds with the numbers on the tree bitmap. These coordinates are brought in via a list called spots.

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#  list of circle positions
spots = (
    (246, 53),
    (246, 75),
    (206, 42),
    (206, 64),
    (206, 86),
    (176, 31),
    (176, 53),
    (176, 75),
    (176, 97),
    (136, 42),
    (136, 64),
    (136, 86),
    (106, 31),
    (106, 53),
    (106, 75),
    (106, 97),
    (66, 31),
    (66, 53),
    (66, 75),
    (66, 97),
    (36, 20),
    (36, 42),
    (36, 64),
    (36, 86),
    (36, 108)
    )

The 25 circles are created using a for statement. This allows the list of coordinates to be iterated through so that each circle will be in the correct position. All of the circles have a radius of 11 and 0xFF00FF as the default color, causing them to appear as a dark grey.

Each circle is added to the circle_group as they are created. After all 25 circles are created, the circle_group is added to group, joining tree_group.

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#  circles to cover-up bitmap's number ornaments

#  creating the circles & pulling in positions from spots
for spot in spots:
    circle = Circle(x0=spot[0], y0=spot[1],
                    r=11,
                    fill=0xFF00FF)
	#  adding circles to their display group
    circle_group.append(circle)

#  adding circles group to main display group
group.append(circle_group)

The MagTag gathers the current time with the function magtag.get_local_time(). time.localtime() is called to parse the time data, including the month and date, into an array that can be accessed.

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#  grabs time from network
magtag.get_local_time()
#  parses time into month, date, etc
now = time.localtime()
month = now[1]
day = now[2]

Additionally, the time is pulled down as well and put into an equation to figure out how many seconds it has been since midnight. This will be used to calculate how long the MagTag should go into deep sleep for.

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(hour, minutes, seconds) = now[3:6]
seconds_since_midnight = 60 * (hour*60 + minutes)+seconds
print( f"day is {day}, ({seconds_since_midnight} seconds since midnight)")

The countdown's progress is revealed on the tree with a for statement. The circle_group is iterated through with the date number acting as the range. The circles that fall in that range have their fill set to None. As a result, the numbers on the bitmap tree are shown for the dates that have passed and the current date.

Download File

#  sets colors of circles to transparent to reveal dates that have passed & current date
for i in range(day):
    circle_group[i].fill = None
    time.sleep(0.1)

The MagTag's display is updated to show group, which includes the tree bitmap and the circles. This is followed by a refresh, which is necessary when updating an E-Ink display.

Download File

#  updates display with bitmap and current circle colors
magtag.display.show(group)
magtag.display.refresh()
time.sleep(5)

Finally, the MagTag enters a deep sleep until midnight after calculating how many seconds have passed since the previous midnight. With deep sleep, you can keep this project running on a battery for a long time since the power draw is minimal. Additionally, there is no need for a loop since the entire code will run again from the beginning when the MagTag awakens.

Download File

print("entering deep sleep")
seconds_to_sleep = 24*60*60 - seconds_since_midnight + 10
print( f"sleeping for {seconds_to_sleep} seconds")
magtag.exit_and_deep_sleep(seconds_to_sleep)

#  entire code will run again after deep sleep cycle
#  similar to hitting the reset button

3D Printing

Parts List

STL files for 3D printing are oriented to print "as-is" on FDM style machines. Parts are designed to 3D print without any support material. Original design source may be downloaded using the links below.

• fancy-portrait.stl

• fancy-landscape.stl

Slicing Parts

Slice with setting for PLA material. The parts were sliced using CURA using the slice settings below.

PLA filament

215c extruder

0.2 layer height

10% gyroid infill

60mm/s print speed

60c heated bed

Design Source Files

The project assembly was designed in Fusion 360. This can be downloaded in different formats like STEP, STL and more. Electronic components like Adafruit's board, displays, connectors and more can be downloaded from the Adafruit CAD parts GitHub Repo.

Download STLs

Download CAD files

Attach the MagTag to the Stand

Use two M3 x 8mm screws to secure the MagTag to the stand.

制造商零件编号 4800

ADAFRUIT MAGTAG - 2.9" GRAYSCALE

Adafruit Industries LLC

¥301.72

查看更多内容 Details

制造商零件编号 4474

CABLE A PLUG TO C PLUG 3'

Adafruit Industries LLC

¥42.19

查看更多内容 Details

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