Simple hack to display a rotation of current time, current atmospheric pressure, and today's pollen forecast, on a Pimoroni ScrollpHAT HD display, attached to a Pi Zero W.
As of 2019-05-17 there's minimal handling on API update requests, so this won't necessarily be very roboust. But it mostly works in my testing – though see below for pollen count issue.
Totals about 10% CPU on a Pi Zero W, with just this script running on a no-GUI Raspbian install. Initial RAM usage is about 50Mb for the whole system.
pip3 install required for:
pyowm
pyquery
apt install required for:
sudo apt-get install libxslt-dev
(lxml install with pyquery is partly broken on Raspbian Stretch, misses this library.)
Sign up for an OpenWeatherMap API key, add to clientsecrets.py file in project root:
owmkey = '<key here>'
Also using the Benadryl Social Pollen Count(!), which builds on the Met. Office's pollen forecast with arm-waving something something. However, the API is drop-dead simple using the pypollen module.
Download to ~/DataBot (assuming using pi user).
See Raspberry Pi docs for systemctl instructions; .service file provided, needs copying into /etc/systemd/system/ and enabling (test with start first).
As of 2019-05-17 updates using the PyPollen library to query the Benadryl site is flaky. I'm seeing some API errors, some slow updates, and some silent failures. From 2019-08-11 a revised UpdatePollen method scrapes the Met Office website directly and parses it using PyQuery.
2020-06-23: Updated to allow for 'Very High' pollen reports, which somehow I'd missed last year.
- Refactor this code to be a bit less ridiculous with global variables. That is: actually return variables sensibly. This is a bit tricky with the update jobs running as background threads, though, and that seems neater than hard-coding updates into the main loop. Maybe the main loop should handle API calls and the background thread should cycle the display? Or mumble mumble classes and objects mumble?