Building an eInk Info Display For My Living Room — November 3, 2019

Building an eInk Info Display For My Living Room

Like a lot of Londoners, my trip to and from work involves moving between a few different trains, any of which could be delayed and cause me to be late to work. Or worse – late home. As checked the tube status on my phone over breakfast one morning, I realised that it would be super useful to have some kind of display in my living room allowing me to see at a glance how my commute is looking before I set off, so I can go a different way if needed.

There are a few options to create a display like this – I could re-purpose a tablet or phone in the technology graveyard drawer, writing a quick and dirty app to run on it. But where would the fun in that be? Sure, it would work but I wanted to learn something along the way. I decided to use a Raspberry Pi and a display of some kind, but if its going to live in my house, it needs to be pretty.

I ordered the Primoroni Inky wHAT – an eInk display with all the headers to screw it directly onto a Raspberry PI. It even has Python library for displaying stuff. I went for the two-colour red/black model; I thought I could use the red mode to make any tube status issues stand out.

Features

As soon as I’d ordered the screen, I started thinking about what I would use it for. I came up with a few things I wanted to do:

  • Display the current tube status of the most useful tube lines
  • Display the current weather / temperature outside from DarkSky
  • Show the current indoor temperature, pulled from my Air Quality Monitor (I built this a couple of years back, I might cover it in a later post)
  • Display some kind of indication that central heating is on or off
  • Show the time

I drew this little diagram to get started:

Implementation

APIs

Ever the software engineering project, the first task was to investigate the APIs to give me the data I wanted.

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