README.md

zabiny-temp

Summary

Check current temperature in Brno-Žabovřesky taken from CHMI/ČHMU

The only data that CHMI provides from the meteorological station in Brno-Žabovřesky is a graph here: http://portal.chmi.cz/files/portal/docs/poboc/PR/grafy/br/grafy-ams-lnk.html

The goal of this project is to read the graphical representation of that image and return the current temperature as a number. A json file with the temperature and timestamp is then exposed via nginx running in an addon in my installation of Home Assistant.

There are two pieces that make up this project:

1. Python script

   This parses the image and returns the current temperature and the corresponding time read from the image.

2. Home Assistant addon

   This is a container that runs the python script periodically and exposes the resulting json via nginx web server.

How to run the standalone python app

Clone the repo

git clone https://github.com/mmalina/zabiny-temp.git
cd zabiny-temp

Install virtual environment, install deps and run the script

python3 -m venv venv
source venv/bin/activate
pip3 install -r requirements.txt
python3 zabinytemp.py

How to install addon

This addon is meant to be consumed in Home Assistant as a local addon via cloning the repo.

Clone this repo in the addons/ volume (e.g. mounted via the samba HA add-on), then refresh the add-ons and install the local addon. Once the add-on is running, the resulting json will be available on the internal network inside HA containers. You can get the temperature via the restfull sensor in HA using the local address http://local-zabiny-temp/temp.json .

Legacy Setup

In the past, the app would be deployed in a public cloud and I would be able to consume and display the data using a Connect IQ app running on my Garmin fenix 5s watch.

Connect IQ app

This is a simple app based on the WebRequest sample app included in the Connect IQ SDK. It loads the json from my webhosting and displays the temperature and delay in minutes between the time read from the image and current time.

Contents

The files and directories included in this repo.

ZabinyTemp

This is the Eclipse project for the Connect IQ app. You can easily import it into Eclipse. See here for for more information about Connect IQ app development: https://developer.garmin.com/connect-iq/programmers-guide/getting-started/

config.json

Home Assistant addon config.

Dockerfile

Definition of the Home Assistant addon container.

requirements.txt

Python modules required for zabinytemp.py.

run.sh

The main script that is started in the container. It periodically runs zabinytemp.py to check the current temperature and saves the json in /data (this is the persistent volume available to each Home Assistant addon and the nginx web server is configured to use it as document root).

zabinytemp.py

Python app that returns the current temperature read from the image on CHMI web.