School Bell

Python-scheduled ringing of a school bell.

A Python-wrapper to the OpenHolidays API is used to optionally disable ringing on public and school holidays. Check the Live Status of the online service.

Setup

See the guide how to configure a Raspberry Pi and Python 3.9 virtual environment from scratch.

Install the Python package using pip.

pip install git+https://github.com/psmsmets/school-bell.git

Usage

Type school-bell --help for the usage.

usage: school-bell [-h] [-b [..]] [--debug] [--demo] [--version] config

Python scheduled ringing of the school bell.

positional arguments:
  config                JSON configuration (string or file)

optional arguments:
  -h, --help            show this help message and exit
  -b [..], --buzz [..]  Buzz via RPi GPIO while the WAVE audio file plays
                        (default: False)
  -p [..], --play [..]  Play a WAVE audio file by specifying the key from the
                        JSON configuration and exit (default: False)
  --debug               Make the operation a lot more talkative
  --demo-config         Print the demo JSON configuration and exit
  --demo-service        Print the demo systemctl service for the current user and exit
  --test                Play one second samples of each WAVE audio file from
                        the JSON configuration at startup (default: False)
  --update [..]         Update school-bell from git. Optionally set the branch (default: main)
  --version             Print the version and exit

Configuration (JSON)

{
    "schedule": {
        "Mon": {"08:30": 0, "12:00": 0, "15:00": 0},
        "Tue": {"08:30": 0, "12:00": 0, "15:00": 0},
        "Wed": {"08:30": 0, "12:00": 0},
        "Thu": {"08:30": 0, "12:00": 0, "15:00": 0},
        "Fri": {"08:30": 0, "12:00": 0, "15:00": 0}
    },
    "trigger": {
        "pibell2": "${HOME}/samples"
    },
    "wav": {
        "0": "SchoolBell-SoundBible.com-449398625.wav",
        "1": "ClassBell-SoundBible.com-1426436341.wav"
    },
    "root": "${HOME}/samples",
    "device": "Headphones",
    "holidays": "NL-BE",
    "timeout": 10
}

The remote trigger requires an ssh-key to connect to the remote host!

Generate a new ssh-key named school-bell in ${HOME}/.ssh/id_school_bell and upload it to the Raspberry Pi with hostname pibell2

ssh-keygen -t rsa -b 4096 -C "school-bell" -N "" -f ${HOME}/.ssh/id_school_bell
ssh-copy-id -f -i${HOME}/.ssh/id_school_bell pi@pibell2.local

Add the following configuration for pibell2 to ~/.ssh/config:

Host pibell2
    HostName pibell2.local
    User pi
    ForwardX11 no
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/id_school_bell

Systemd service

Create a systemd service of the school-bell. An example service is given by the command school-bell --demo-service for the current user with the configuration in ${HOME}/school-bell.json. The service can be modified if needed.

school-bell --demo-service | sudo tee /etc/systemd/system/school-bell.service
sudo systemctl daemon-reload
sudo systemctl enable school-bell
sudo systemctl start school-bell

Check the status of the school-bell service

$ systemctl status school-bell
● school-bell.service - Scheduled school bell
     Loaded: loaded (/etc/systemd/system/school-bell.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2022-02-23 15:21:25 CET; 17s ago
   Main PID: 1192 (school-bell)
      Tasks: 1 (limit: 840)
        CPU: 762ms
     CGroup: /system.slice/school-bell.service
             └─1192 /home/pi/.local/bin/python3 /home/pi/.local/bin/school-bell /home/pi/school-bell.json --debug

Feb 23 15:21:28 pibell school-bell[1192]: 2022-02-23 15:21:28,933 - school bell - INFO - Schedule started

Logs are handled via syslog. Show all logs of today:

journalctl -u school-bell --since=today

Licensing

The source code for school-bell is open-source and licensed under MIT.

Pieter Smets © 2024. All rights reserved.