Weather Display Matrix

2022-05-24 | By Adafruit Industries

License: See Original Project

Guide by John Park

Overview

Always know the current weather without even sticking you head out ‎the window with the Weather Display Matrix.‎

display_1

Using CircuitPython, this project queries the Open Weather Maps site ‎API to find out the current weather for your location. It displays the ‎temperature and weather condition icon, while scrolling additional ‎details such as humidity and conditions.‎

Want to change between Imperial and metric units? We've got you ‎covered! Use the Matrix Portal buttons or the added jumper on the ‎Metro M4 Airlift's pin D12 to do so.‎

Parts

Adafruit Metro M4 Express AirLift (WiFi) - Lite

Optional

Using M4 Airlift

If you have a Metro M4 AirLift, you can build this project easily - you ‎just need an RGB Matrix shield to help connect!‎

You will need a Metro M4 Airlift, matrix shield and matrix.

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 Quick Start!‎

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

Download the latest version of CircuitPython for this board via ‎circuitpython.org

Further Information

For more detailed info on installing CircuitPython, check out Installing ‎CircuitPython.‎

Click the link above and download the latest UF2 file.‎

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

download_2

Plug your Metro M4 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 next to the USB connector on your ‎board, and you will see the NeoPixel RGB LED (indicated by the arrow) ‎turn green. If it turns red, check the USB cable, try another USB port, ‎etc.‎

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 METROM4BOOT.‎‎ ‎

Drag the adafruit_circuitpython_etc.uf2 file to METROM4BOOT.‎

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The LED will flash. Then, the METROM4BOOT drive will disappear, and ‎a new disk drive called CIRCUITPY will appear.‎

That's it, you're done! :)‎

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Build Metro M4 Airlift Matrix ‎Display

Assembly

Talking to an LED matrix display can be tricky! The 64 x 32 LED used ‎here has a whopping 2,048 pixels, and each can display RGB colors, ‎which makes for a whole lot of data to sling around. Thankfully, our ‎RGB Matrix shield paired with the Metro M4 Airlift does most of the ‎heavy lifting.‎

Let's assemble the boards and the display so we can get things running!‎

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Shields Up

First, add the male headers, screw terminal block, and the 8x2-pin ‎socket to the Matrix shield, by following this guide. Be careful to ‎match the socket polarity to the silkscreen image on the board.‎

Be sure to also perform the clock pin mod as shown here.‎

Then plug the shield into the Metro M4 Airlift.‎

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Power Connections

To provide power, we'll screw the wiring harness connectors to the ‎screw terminal blocks of the shield. Be sure to match the black wire ‎to GND and the red wire to +5Vout.‎

Now, simply plug the other end into the panel's power header. It can ‎only go in one way.‎

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Data Cable

Plug in the two ends of the ribbon cable, note that the connectors are ‎keyed to only fit in the correct orientation.‎

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Wall Adapter

We'll power the Metro M4 from the 5V 2.5 (or a 4A) DC wall adapter ‎plugged into the barrel jack. Even though USB can provide power to the ‎board, the current isn't adequate for lighting up hundreds and ‎thousands of LEDs!‎

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For info on adding LED diffusion acrylic, see the page LED Matrix ‎Diffuser.‎

Using MatrixPortal

You can build this project with an all-in-one Matrix Portal board, it’s ‎definitely the easiest and least-expensive way to go about it.‎

You will need a matrix portal, matrix, and USB C power/data cable.

Prep the MatrixPortal

Power Prep

The MatrixPortal supplies power to the matrix display panel via two ‎standoffs. These come with protective tape applied (part of our ‎manufacturing process) which MUST BE REMOVED!‎

Use some tweezers or a fingernail to remove the two amber circles.‎

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Power Terminals

Next, screw in the spade connectors to the corresponding standoff.‎

red wire goes to +5V
black wire goes to GND

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Panel Power

Plug either one of the four-conductor power plugs into the power ‎connector pins on the panel. The plug can only go in one way, and that ‎way is marked on the board's silkscreen.‎

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Board Connection

Now, plug the board into the left side shrouded 8x2 connector as ‎shown. The orientation matters, so take a moment to confirm that ‎the white indicator arrow on the matrix panel is oriented ‎pointing up and right as seen here and the MatrixPortal overhangs ‎the edge of the panel when connected. This allows you to use the edge ‎buttons from the front side.‎‎

‎Check nothing is impeding the board from plugging in firmly. If there's ‎a plastic nub on the matrix that's keeping the Portal from sitting flat, ‎cut it off with diagonal cutters.‎

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For info on adding LED diffusion acrylic, see the page LED Matrix ‎Diffuser.‎

Install CircuitPython

Set up CircuitPython Quick Start!‎

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

Download the latest version of CircuitPython for this board via ‎circuitpython.org

Further Information

For more detailed info on installing CircuitPython, check out Installing ‎CircuitPython.‎

Click the link above and download the latest UF2 file.‎

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

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Plug your MatrixPortal M4 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 (indicated by the green arrow) on your ‎board, and you will see the NeoPixel RGB LED (indicated by the ‎magenta arrow) turn green. If it turns red, check the USB cable, try ‎another USB port, etc.‎

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

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You will see a new disk drive appear called MATRIXBOOT.‎‎ ‎

Drag the adafruit_circuitpython_etc.uf2 file to MATRIXBOOT.‎

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

That's it, you're done! :)‎

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Code the Weather Display Matrix

Libraries

We'll need to make sure we have these libraries installed. (Check out ‎this link on installing libraries if needed.)

adafruit_bitmap_font
adafruit_bus_device
adafruit_display_shapes
adafruit_display_text
adafruit_esp32spi
adafruit_io
adafruit_matrixportal
adafruit_requests.mpy
neopixel.mpy

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Connect to the Internet

Once you have CircuitPython setup and libraries installed we can get ‎your board connected to the Internet. The process for connecting can ‎be found here.‎

Text Editor

Adafruit recommends using the Mu editor for editing your ‎CircuitPython code. You can get more info in this guide.‎

Alternatively, you can use any text editor that saves simple text files.‎

Code

Click the Download: Zip File link below in the code window to get a zip ‎file with all the files needed for the project. ‎Copy weather_display_matrix.py from the zip file and place on ‎the CIRCUITPY drive, then rename it to code.py.‎

You'll also need to copy the following files to the CIRCUITPY drive. See ‎the graphic at the top of the page as to filenames and where they go):‎

fonts directory, which contains three bitmap fonts
loading.bmp
openweather_graphics.py
weather-icons.bmp
secrets.py (after you edit to put your Wi-Fi and weather ‎credentials in the file, noted below)‎

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# SPDX-FileCopyrightText: 2020 John Park for Adafruit Industries
#
# SPDX-License-Identifier: MIT

# Matrix Weather display
# For Metro M4 Airlift with RGB Matrix shield, 64 x 32 RGB LED Matrix display

"""
This example queries the Open Weather Maps site API to find out the current
weather for your location... and display it on a screen!
if you can find something that spits out JSON data, we can display it
"""
import time
import board
import microcontroller
from digitalio import DigitalInOut, Direction, Pull
from adafruit_matrixportal.network import Network
from adafruit_matrixportal.matrix import Matrix
import openweather_graphics  # pylint: disable=wrong-import-position

# 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 hasattr(board, "D12"):
    jumper = DigitalInOut(board.D12)
    jumper.direction = Direction.INPUT
    jumper.pull = Pull.UP
    is_metric = jumper.value
elif hasattr(board, "BUTTON_DOWN") and hasattr(board, "BUTTON_UP"):
    button_down = DigitalInOut(board.BUTTON_DOWN)
    button_down.switch_to_input(pull=Pull.UP)

    button_up = DigitalInOut(board.BUTTON_UP)
    button_up.switch_to_input(pull=Pull.UP)
    if not button_down.value:
        print("Down Button Pressed")
        microcontroller.nvm[0] = 1
    elif not button_up.value:
        print("Up Button Pressed")
        microcontroller.nvm[0] = 0
    print(microcontroller.nvm[0])
    is_metric = microcontroller.nvm[0]
else:
    is_metric = False

if is_metric:
    UNITS = "metric"  # can pick 'imperial' or 'metric' as part of URL query
    print("Jumper set to metric")
else:
    UNITS = "imperial"
    print("Jumper set to imperial")

# Use cityname, country code where countrycode is ISO3166 format.
# E.g. "New York, US" or "London, GB"
LOCATION = "Los Angeles, US"
print("Getting weather for {}".format(LOCATION))
# Set up from where we'll be fetching data
DATA_SOURCE = (
    "http://api.openweathermap.org/data/2.5/weather?q=" + LOCATION + "&units=" + UNITS
)
DATA_SOURCE += "&appid=" + secrets["openweather_token"]
# You'll need to get a token from openweather.org, looks like 'b6907d289e10d714a6e88b30761fae22'
# it goes in your secrets.py file on a line such as:
# 'openweather_token' : 'your_big_humongous_gigantor_token',
DATA_LOCATION = []
SCROLL_HOLD_TIME = 0  # set this to hold each line before finishing scroll

# --- Display setup ---
matrix = Matrix()
network = Network(status_neopixel=board.NEOPIXEL, debug=True)
if UNITS in ("imperial", "metric"):
    gfx = openweather_graphics.OpenWeather_Graphics(
        matrix.display, am_pm=True, units=UNITS
    )

print("gfx loaded")
localtime_refresh = None
weather_refresh = None
while True:
    # only query the online time once per hour (and on first run)
    if (not localtime_refresh) or (time.monotonic() - localtime_refresh) > 3600:
        try:
            print("Getting time from internet!")
            network.get_local_time()
            localtime_refresh = time.monotonic()
        except RuntimeError as e:
            print("Some error occured, retrying! -", e)
            continue

    # only query the weather every 10 minutes (and on first run)
    if (not weather_refresh) or (time.monotonic() - weather_refresh) > 600:
        try:
            value = network.fetch_data(DATA_SOURCE, json_path=(DATA_LOCATION,))
            print("Response is", value)
            gfx.display_weather(value)
            weather_refresh = time.monotonic()
        except RuntimeError as e:
            print("Some error occured, retrying! -", e)
            continue

    gfx.scroll_next_label()
    # Pause between labels
    time.sleep(SCROLL_HOLD_TIME)

‎View on GitHub

Open Weather Maps API Key

We'll be using OpenWeatherMaps.org to retrieve the weather info ‎through its API. In order to do so, you'll need to register for an account ‎and get your API key.‎

Go to this link and register for a free account. Once registered, you'll ‎get an email containing your API key, also known as the "openweather ‎token".‎

Copy and paste this key into your secrets.py file that is on the root ‎level of your CIRCUITPY drive, so it looks something like this:‎

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secrets = {
        'ssid' : 'your_wifi_ssid',
        'password' : 'your_wifi_password',
        'openweather_token' : 'xxxxxxxxxxxxxxxxxxxxxxxx'
    }

Adafruit IO Time Server

In order to get the precise time, our project will query the Adafruit IO ‎Internet of Things service for the time. Adafruit IO is absolutely free to ‎use, but you'll need to log in with your Adafruit account to use it. If ‎you don't already have an Adafruit login, create one here.‎

If you haven't used Adafruit IO before, check out this guide for more ‎info.‎

Once you have logged into your account, there are two pieces of ‎information you'll need to place in your secrets.py file: Adafruit IO ‎username, and Adafruit IO key. Head to io.adafruit.com and simply ‎click the View AIO Key link on the left-hand side of the Adafruit IO ‎page to get this information.‎

Then, add them to the secrets.py file like this:‎

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secrets = {
    'ssid' : 'your_wifi_ssid',
    'password' : 'your_wifi_password',
    'openweather_token' : 'xxxxxxxxxxxxxxxxxxxxxxxx',
    'aio_username' : '_your_aio_username_',
    'aio_key' : '_your_big_huge_super_long_aio_key_'
}

Problems Getting Data

If you have any problems getting the data to display correctly, check ‎that the secrets.py file has the information noted above.‎

How it Works

Libraries

First, we import libraries to help us behind the scenes. time will allow ‎us to pause between weather queries. board gives us pin definitions. ‎And we'll use the digitalio library to query a DigitalInOut pin in the ‎input Direction with Pull down resistor for mode selection.‎

The adafruit_matrixportal library will be used both for Network queries ‎and for controlling the Matrix display.‎

We'll also import the openweather_graphics class to take care of the ‎graphics, text display, scrolling and more.‎

Secrets

Next, we import the secrets needed for Wi-Fi access point connection, ‎Open Weather Maps key, and more.‎

Units

Want to change between Imperial and metric units? We've got you ‎covered! Use the Matrix Portal buttons or the added jumper on the ‎Metro M4 Airlift's pin D12 to do so.‎

Jumper

For the Metro M4 Airlift version, next we set up a digital input pin and ‎a variable called jumper in order to switch the device from imperial to ‎metric units.‎

Buttons

For the Matrix Portal version, we can use the on-board buttons instead. ‎By holding down one of the buttons while you power on the Matrix ‎Portal, you can set unit mode of the display. The value is stored in ‎non-volatile memory and is automatically used the next time the ‎Matrix Portal is powered on.‎

Hold Down for metric mode
Hold Up for imperial mode

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if hasattr(board, "D12"):
    jumper = DigitalInOut(board.D12)
    jumper.direction = Direction.INPUT
    jumper.pull = Pull.UP
    is_metric = jumper.value
elif hasattr(board, "BUTTON_DOWN") and hasattr(board, "BUTTON_UP"):
    button_down = DigitalInOut(board.BUTTON_DOWN)
    button_down.switch_to_input(pull=Pull.UP)

    button_up = DigitalInOut(board.BUTTON_UP)
    button_up.switch_to_input(pull=Pull.UP)
    if not button_down.value:
        print("Down Button Pressed")
        microcontroller.nvm[0] = 1
    elif not button_up.value:
        print("Up Button Pressed")
        microcontroller.nvm[0] = 0
    print(microcontroller.nvm[0])
    is_metric = microcontroller.nvm[0]
else:
    is_metric = False

if is_metric:
    UNITS = "metric"  # can pick 'imperial' or 'metric' as part of URL query
    print("Jumper set to metric")
else:
    UNITS = "imperial"
    print("Jumper set to imperial")

Data

We'll set a variable for the DATA_SOURCE which will be used to query ‎Open Weather Maps API next. This query will use ‎the LOCATION and UNITS variables to form the request.‎

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LOCATION = "Los Angeles, US"
print("Getting weather for {}".format(LOCATION))
DATA_SOURCE = (
    "http://api.openweathermap.org/data/2.5/weather?q=" + LOCATION + "&units=" + UNITS
)
DATA_SOURCE += "&appid=" + secrets["openweather_token"]

API Query and JSON

Using this information, the code can then send a query to Open ‎Weather Maps's API that looks something like this:‎

http://api.openweathermap.org/data/2.5/weather?q=Los Angeles, ‎US&appid=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

‎(where all of those 'x's are your token).‎

When this query is complete, it returns a JSON file that looks like this:‎

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{
  "coord": {
    "lon": -118.24,
    "lat": 34.05
  },
  "weather": [
    {
      "id": 501,
      "main": "Rain",
      "description": "moderate rain",
      "icon": "10d"
    }
  ],
  "base": "stations",
  "main": {
    "temp": 287.42,
    "pressure": 1016,
    "humidity": 50,
    "temp_min": 285.15,
    "temp_max": 289.15
  },
  "visibility": 16093,
  "wind": {
    "speed": 3.6,
    "deg": 300
  },
  "rain": {
    "1h": 1.52
  },
  "clouds": {
    "all": 75
  },
  "dt": 1552073935,
  "sys": {
    "type": 1,
    "id": 3514,
    "message": 0.0087,
    "country": "US",
    "sunrise": 1552054308,
    "sunset": 1552096542
  },
  "id": 5368361,
  "name": "Los Angeles",
  "cod": 200
}

JSON Traversal

The JSON file is formatted in a way that makes it easy to traverse the ‎hierarchy and parse the data. In it, you'll see keys, such ‎as main, description, icon, and temp, and their respective values. So, ‎here are some key: value pairs we care about for the weather station:‎

‎"main" : "Rain"
‎"description" : "moderate rain"‎
‎"icon" : "10d"‎
‎"temp" : "287.42"‎

In order to fetch this data from the file, we need to be able to describe ‎their locations in the file hierarchically. This is helpful, for example, in ‎differentiating between the 'main' weather condition and ‎the 'main' section containing temperature and other data. To avoid ‎name clashing we rely on JSON traversal.‎

In the openweather_graphics.py file, you'll see how this is done. For ‎example, the main key is found in this hierarchy of the JSON ‎file: ['weather'], [0], ['main']‎

This means there is a key at the top level of the JSON file ‎called 'weather', which has a sub-tree indexed [0], and then below ‎that is the 'main' key.‎

This process is used to cast the values of the temperature, weather, ‎description, and which icon to display from the directory of bitmap ‎icons.‎

Scroll Time

You can customize your scroll hold time here:‎

SCROLL_HOLD_TIME = 0 # set this to hold each line before finishing ‎scroll

Setting this value to 0 means there will not be a hold when a line of ‎text reaches the edge of the display.‎

Display and Network Setup

The display and network setup are next, along with setting the call to ‎the openweather_graphics class:‎

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matrix = Matrix()
network = Network(status_neopixel=board.NEOPIXEL, debug=True)
if UNITS == "imperial" or UNITS == "metric":
    gfx = openweather_graphics.OpenWeather_Graphics(
        matrix.display, am_pm=True, units=UNITS
    )

Main Loop

In the main loop we check the online time server once an hour to stay ‎in sync with internet time, and we check the weather data every ten ‎minutes, using the gfx call to the openweather_graphics class.‎

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if (not localtime_refresh) or (time.monotonic() - localtime_refresh) > 3600:
        try:
            print("Getting time from internet!")
            network.get_local_time()
            localtime_refresh = time.monotonic()
        except RuntimeError as e:
            print("Some error occured, retrying! -", e)
            continue

    # only query the weather every 10 minutes (and on first run)
    if (not weather_refresh) or (time.monotonic() - weather_refresh) > 600:
        try:
            value = network.fetch_data(DATA_SOURCE, json_path=(DATA_LOCATION,))
            print("Response is", value)
            gfx.display_weather(value)
            weather_refresh = time.monotonic()
        except RuntimeError as e:
            print("Some error occured, retrying! -", e)
            continue

With the json data from Open Weather Maps parsed, we can then scroll ‎through the text labels for weather description, humidity, wind ‎speed, and location.‎

LED Matrix Diffuser

LED Diffusion Acrylic

You can add an LED diffusion acrylic faceplate to your LED matrix ‎display. (Pictured here with the ON AIR project)‎

This can help protect the LEDs as well as enhance the look of the sign ‎both indoors and out by reducing glare and specular highlights of the ‎plastic matrix grid.‎

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Measure and Cut the Plastic

You can use the sign to measure, and mark cut lines on the paper ‎backing of the acrylic sheet.‎

Then, use a tablesaw or bandsaw with a fine-toothed blade and a ‎guide or sled to make the cuts.‎

Note: It is possible to score and snap acrylic, but it can be very tricky to ‎get an even snap without proper clamping.‎

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Peel away the paper backing from both sides and set the acrylic onto ‎your matrix display.‎

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Uglu Dashes

The best method we've found for adhering acrylic to the matrix display ‎is to use Uglu Dashes clear adhesive rectangles from Pro Tapes. They ‎are incredibly strong (although can be removed if necessary), easy to ‎apply, and are invisible once attached.‎

Use one at each corner and one each at the halfway point of the long ‎edges, then press the acrylic and matrix panel together for about 20 ‎seconds.‎

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Here you can see the impact of using the diffusion acrylic. (Pictured ‎here with the ON AIR sign project)‎

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Stand

A very simple and attractive way to display your matrix is with the ‎adjustable bent-wire stand.‎

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Alternately, you can use a frame, 3D printed brackets, tape, glue, or ‎even large binder clips to secure the acrylic to the sign and then mount ‎it on a wall, shelf, or display cabinet.‎

These mini-magnet feet can be used to stick the sign to a ferrous ‎surface.