Another one of my lockdown projects...
I've always like the idea of making an always-on display. Something like the Magic Mirror project here, or a productivity dashboard using an LCD display here, but I also wanted something that is a bit more visible in bright light and uses a little bit less electricity.
Hence, I settled on the idea of making a giant e-ink display that I could use to show whatever I wanted. Until I saw how expensive the panels are, and I settled on a much smaller 7.5" e-ink 2 colour display.
What does it do?
Well, there's a few modes (in case I ever get bored).
Normally, I keep it in weather mode, whereby every 10 minutes it will update and show the following:
- Current weather conditions
- Rain chart for the next few hours
- Air quality
- Sunrise and Sunset times
- The next time the ISS will pass overhead
- Weather radar of the UK (just because it looks cool)
I won't lie, the 3 hour rainwall forecast is nowhere near as accurate as DarkSky was, and the display panel I was sent didn't display red's anywhere near as vibrantly as other panels I have seen (I think it was just a faulty panel but I couldn't be bothered to pay for shipping to China and wait another month), but overall it's worked exactly as I have envisioned!
There's also the cowsay mode, whose sole purpose is to present a random dad joke every hour, in the popular linux cli tool format.
How to build it?
It's relatively simple, really...
The instructions for putting it together are fairly self explanatory, so I'm not going to bore you. Setting up a headless Raspberry Pi (so you can just access it over SSH is explained beautifully simply over at the Raspberry Pi site) Aside from that it's just plug and play.
The software is a little bit more of a pain in the ass, Waveshare have a GitHub repo with drivers for each of their displays, but no perfect method of building a UI for these displays, so the best way to push something to the display is in the form of a bitmap (essentially png) image. The refresh rate of the display is a pathetic ~1 minute so don't worry too much about how long it takes to build that image.
I have a repository with all the code for this project on my GitHub here, that you just need to clone into the RPI's home directory, and then write your own
settings.py file from the example file provided.
It makes extensive use of various API's, including Climacell for the weather data, ISS Open Notify for the ISS times, ICanHazDadJoke for the dad joke service, and This online cowsay generator because I couldn't be bothered to generate it myself, although looking back it would probably have been easier to do it manually.
For the map images, I used the OpenStreetMap Toner style tiles for the map and the MetOffice rain radar tiles for the rain overlays. I originally used OpenWeatherMap, but whilst it was good at global coverage of rainfall, it had very low resolution.
To run the scripts all you need to do is create a cron job for it to update every x minutes.
You can enter the cron editor with
crontab -e and just input
*/10 * * * * python3 /home/pi/mappyboi.py for a 10 minute update schedule.
I practically never do hardware projects and this has been super fun!
I'm still thinking of ideas to use it for (if you have any ideas of a cool use for this format of display, contact me!)
Ideas I've currently considered: