METARMap

Raspberry Pi project to visualize flight conditions on a map using WS8211 LEDs addressed via NeoPixel

Detailed instructions

I've created detailed instructions about the setup and parts used here: https://slingtsi.rueker.com/making-a-led-powered-metar-map-for-your-wall/

Software Setup

• Install Raspberry Pi OS Lite on SD card
• Enable Wi-Fi and SSH
• Install SD card and power up Raspberry Pi
• SSH (using Putty or some other SSH tool) into the Raspberry and configure password and timezones
  • passwd
  • sudo raspi-config
• Update packages
  • sudo apt-get update
  • sudo apt-get upgrade
• Copy the metar.py, pixelsoff.py, airports, refresh.sh and lightsoff.sh scripts into the pi home directory (/home/pi)
• Install python3 and pip3 if not already installed
  • sudo apt-get install python3
  • sudo apt-get install python3-pip
• Install required python libraries for the project
  • Neopixel: sudo pip3 install rpi_ws281x adafruit-circuitpython-neopixel
• Attach WS8211 LEDs to Raspberry Pi, if you are using just a few, you can connect the directly, otherwise you may need to also attach external power to the LEDs. For my purpose with 22 powered LEDs it was fine to just connect it directly. You can find more details about wiring here.
• Test the script by running it directly (it needs to run with root permissions to access the GPIO pins):
  • sudo python3 metar.py
• Make appropriate changes to the airports file for the airports you want to use and change the metar.py and pixelsoff.py script to the correct LED_COUNT (including NULLs if you have LEDS in between airports that will stay off) and LED_BRIGHTNESS if you want to change it
• To run the script automatically when you power the Raspberry Pi, you will need to grant permissions to execute the refresh.sh and lightsoff.sh script and read permissions to the airports, metar.py and pixelsoff.py script using chmod:
  • chmod +x filename will grant execute permissions
  • chmod +r filename will grant write permissions
• To have the script start up automatically and refresh in regular intervals, use crontab and set the appropriate interval. For an example you can refer to the crontab file in the GitHub repo (make sure you grant the file execute permissions beforehand to the refresh.sh and lightsoff.sh file). To edit your crontab type: crontab -e, after you are done with the edits, exit out by pressing ctrl+x and confirm the write operation
  • The sample crontab will run the script every 5 minutes (the */5) between the hours of 7 to 21, which includes the 21 hour, so it means it will run until 21:55
  • Then at 22:05 it will run the lightsoff.sh script, which will turn all the lights off

Additional Wind condition blinking/fading functionality

I recently expanded the script to also take wind condition into account and if the wind exceeds a certain threshold, or if it is gusting, make the LED for that airport either blink on/off or to fade between two shades of the current flight category color.

If you want to use this extra functionality, then inside the metar.py file set the ACTIVATE_WINDCONDITION_ANIMATION parameter to True.

• There are a few additional parameters in the script you can configure to your liking:
  • FADE_INSTEAD_OF_BLINK - set this to either True or False to switch between fading or blinking for the LEDs when conditions are windy
  • WIND_BLINK_THRESHOLD - in Knots for normal wind speeds currently at the airport
  • ALWAYS_BLINK_FOR_GUSTS - If you always want the blinking/fading to happen for gusts, regardless of the wind speed
  • BLINKS_SPEED - How fast the blinking happens, I found 1 second to be a happy medium so it's not too busy, but you can also make it faster, for example every half a second by using 0.5
  • BLINK_TOTALTIME_SECONDS = How long do you want the script to run. I have this set to 300 seconds as I have my crontab setup to re-run the script every 5 minutes to get the latest weather information
  • HIGH_WINDS_THRESHOLD - If you want LEDs to flash to Yellow for particularly high winds beyond the normal WIND_BLINK_THRESHOLD then set this variable in knots. If you only want normal blinking/fading based on WIND_BLINK_THRESHOLD then set the value for HIGH_WINDS_THRESHOLD to -1

Additional Lightning in the vicinity blinking functionality

After the recent addition for wind condition animation, I got another request from someone if I could add a white blinking animation to represent lightning in the area. Please note that due to the nature of the METAR system, this means that the METAR for this airport reports that there is Lightning somewhere in the vicinity of the airport, but not necessarily right at the airport.

If you want to use this extra functionality, then inside the metar.py file set the ACTIVATE_LIGHTNING_ANIMATION parameter to True.

• This shares two configuration parameters together with the wind animation that you can modify as you like:
  • BLINKS_SPEED - How fast the blinking happens, I found 1 second to be a happy medium so it's not too busy, but you can also make it faster, for example every half a second by using 0.5
  • BLINK_TOTALTIME_SECONDS = How long do you want the script to run. I have this set to 300 seconds as I have my crontab setup to re-run the script every 5 minutes to get the latest weather information

Additional LED dimming functionality based on time of day

This optional functionality allows you to run the LEDs at a dimmed lower level between a certain time of the day.

If you want to use this extra functionality, then inside the metar.py file set the ACTIVATE_DAYTIME_DIMMING parameter to True. Set the LED_BRIGHTNESS_DIM setting to the level you want to run when dimmed.

For time timings of the dimming there are two options:

• Fixed time of day dimming:
  • BRIGHT_TIME_START - Set this to the beginning of the day when you want to run at the normal LED_BRIGHTNESS level
  • DIM_TIME_START - Set this to the time where you want to run at a different LED_BRIGHTNESS_DIM level
• Dimming based on local sunrise/sunset:
  • For this to work, you need to install an additional library, run:
    • sudo pip3 install astral
  • USE_SUNRISE_SUNSET - Set this to True to use the dimming based on sunrise and sunset
  • LOCATION - set this to the city you want to use for sunset/sunrise timings
    • Use the closest city from the list of supported cities from https://astral.readthedocs.io/en/latest/#cities

Additional mini display to show METAR information functionality

This optional functionality allows you to connect a small mini LED display to show the METAR information of the airports.

For this functionality to work, you will need to buy a compatible LED display and enable and install a few additional things.

I've written up some details on the display I used and the wiring here: https://slingtsi.rueker.com/adding-a-mini-display-to-show-metar-information-to-the-metar-map/

To support the display you need to enable a few new libraries and settings on the raspberry pi.

• Enable I2C
• sudo raspi-config
• Interface Options
• I2C
• reboot the Reboot the Raspberry Pi sudo reboot
• Verify your wiring is working and I2C is enabled
  • sudo apt-get install i2c-tools
  • sudo i2cdetect -y 1 - this should show something connected at 3C
• install python library for the display
  • sudo pip3 install adafruit-circuitpython-ssd1306
  • sudo pip3 install pillow
• install additional libraries needed to fill the display
  • sudo apt-get install fonts-dejavu
  • sudo apt-get install libjpeg-dev -y
  • sudo apt-get install zlib1g-dev -y
  • sudo apt-get install libfreetype6-dev -y
  • sudo apt-get install liblcms1-dev -y
  • sudo apt-get install libopenjp2-7 -y
  • sudo apt-get install libtiff5 -y
• copy new file displaymetar.py into the same folder as metar.py
• Use the latest version of metar.py and pixelsoff.py for the new functionality
• Configure metar.py and set ACTIVATE_EXTERNAL_METAR_DISPLAY parameter to True.
• Configure the DISPLAY_ROTATION_SPEED to your desired timing, I'm using 5 seconds for mine.
• If you want to only show a subset of the airports on the display, create a new file in the folder called displayairports and add the airports that you want to be shown on the display to it

Legend

If you want an interactive Legend to illustrate the possible behaviors you can do so by adding an additional up to 7 LEDs after the last LED based on your number of LEDs of the airports in the airports file

• Set SHOW_LEGEND to True to use this feature
• If you want to skip some LEDs after your last airport before the legend, you can set OFFSET_LEGEND_BY to the number of LEDs to skip
• Note: The Lightning and Wind Condition LEDs will only show if you are actually using these features based on the ACTIVATE_LIGHTNING_ANIMATION, ACTIVATE_WINDCONDITION_ANIMATION and HIGH_WINDS_THRESHOLD variables.
  • If you are not using any of these, then you only need 4 LEDs for the basic flight conditions for the Legend
  • If you are only using the Wind condition feature, but not the Lightning, you will still need the total of 7 LEDs (but the 5th LED for Lightning will just stay blank) or you'd have to change the order in the code

Changelist

To see a list of changes to the metar script over time, refer to CHANGELIST.md