Project: HomeTemp v0.5

The original idea of HomeTemp was to automatically measure the temperature and humidity of a room and create plots visualizing the data. Currently supported temperature and humidity sensors are AM2302. DHT11 and DHT22 sensor, connected to a Raspberry Pi 4 Model B or Raspberry Pi 5. The fork BaseTemp was created to periodically measure and save the temperature and humidity of my basement. It also takes pictures using a 5MP Raspberry Pi camera module with an OV5647 sensor and is able to take and send a live picture via commanding.

Requirements

• screen
• Docker
• libpq-dev
• xvfb
• Python >= 3.9
• Everything in requirements.txt for pip

Current Features

• Initializing Docker container for Postgres database or reuse existing
• Connecting to postgres database
• CRUD operations for tables and columns
• Creating data visualizations using seaborn and matplot
• Sending emails containing statistic data as text and visualizations as pdf
• Data fetching from various API endpoints/websites
• Commanding via email
• Taking pictures (timed or commanded) via camera module (only tested on Raspberry Pi 4 Model B)
• Create timelapse video of a set of pictures

Installation Instructions

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

Install Dependencies

Use this code snippet to install the required dependencies. Either use pip install with module name or use the requirements file.

Install System Dependencies

Install docker, e.g., as described here for raspberry-pi.

sudo apt update
sudo apt install screen libpq-dev xvfb

In case data fetching from endpoints is a desired feature, chromedriver has to be installed as well (see below).

Setup Virtual Environment

For venv setup, use --system-site-package parameter. The following snippets creates the environment in the folder .venv.

python -m venv --system-site-packages .venv

Install Python Dependencies

It is recommended to install the dependencies via requirements.txt. Using the latest dependencies via modules names might cause problems.

# Recommended
pip install -r requirements.txt
# or at own risk Module names
pip install opencv-python pillow rpi-lgpio RPI.GPIO lgpio psycopg2 gpiozero docker seaborn SQLAlchemy requests selenium schedule pyvirtualdisplay bs4 jupyter_client jupyter_core

Create config.ini

At first, rename default_config.ini to config.ini and assign values to all variables. The field instance defines to start HomeTemp (hometemp) or BaseTemp (basetemp).

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
# or if not existing
sudo chmod -R 755 /usr/bin/chromedriver

Start Instructions

When everything is set up as intended, it should be enough to run ./start.sh [basetemp|hometemp]. In case it didn't work, the following sections provide information and tips for starting the related services and dependencies.

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

Afterward, 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'))

It is also possible to start the container via the following command. HomeTemp will use this container if the name of the container matches the name specified in config.ini.

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.

Update/Restore Instructions

Use the following commands to import and export database:

# Just open pqsql console (leave \q)
docker exec -it postgres-db bash -c "PGPASSWORD='<DB_PASSWORD>' psql -U <DB_USER> -d <DB_NAME>"
# Export
docker exec -t postgres-db sh -c 'PGPASSWORD=<DB_PASSWORD> pg_dump -U <DB_USER> <DB_NAME>' > backup.sql

# Import
# start container
docker cp backup.sql postgres-db:/backup.sql
docker exec -i postgres-db sh -c 'PGPASSWORD=<DB_PASSWORD> psql -U <DB_USER> -d <DB_NAME>' < backup.sql