Project: HomeTemp v0.3.2

The original idea of this project was to automate the periodically measured temperature and humidity values in my apartment. The room temperature and humidity is caputred by an AM2302 sensor, connected to a Raspberry Pi 4 Model B. This idea is still growing prosperously and currently provides the following features:

Current Features

• Connection to postgres db
• Initialize docker container for postgres db or reuse existing
• CRUD operations for tables and columns
• Create data visualizations using seaborn and matplot
• Ability to send emails with text and attached pdf file
• Recover sensor data from log file and save to database
• Ability to fetch data from API endpoints/websites (currently: Deutsche Wetterdienst (DWD) and Google Weather, Ulm.de and Wetter.com)

While hometemp.py is the entrypoint to start periodical data collection and distribution, crunch_numbers.ipynb is a playground for everything.

Installation Instructions

The following steps needs to be performed once to assure correct driver setup.

Configure Hometemp.ini

At first, rename default_hometemp.ini to hometemp.ini and assign values to all variables.

Install Chromedriver

Selenium is used to fetch data from endpoints which rely on Javascript. On a raspberry pi, install chromium driver with the following command and set permissions:

sudo apt-get install chromium-chromedriver
sudo chmod -R 755 /usr/lib/chromium-browser 

Start Instructions

The following sections provide information and tips for starting the related services and dependencies.

Start pigpio Deamon

For retrieving the temperatue values, we (indirectly) use gpiozero to communicate with GPIO pins (e.g., on the raspberry pi). This packages displays warnings when its used for the first time after start. To decrease the warning messages, we can start the deamon with: sudo pigpiod However, this does not remove all warning messages, it just decreases their amount and in terms of accuricy or reliability of data retrieval, we didn't observ any issues.

Start Docker Container

Images and containers should be pulled or created/reused automatically. However, for this to work, the user needs to be added to the docker group:

sudo usermod -aG docker $USER

Afterwards, a reboot is required otherwise the following error will occur:

docker.errors.DockerException: Error while fetching server API version: ('Connection aborted.', PermissionError(13, 'Permission denied'))

This step should be obsolete because the HomeTemp automatically does this. However, it is left for documentation.

docker run --name postgres-db -e POSTGRES_PASSWORD=<ENTER PASSWORD HERE> -d -p 5432:5432 postgres:latest

after a restart, use docker ps -a to get the container ID and then docker start <containerID> to start the old database.