HSL Clock

This tweet on X aspired me to create one for my smart home as well as to learn some Python.

This project sends requests to Helsinki Region Transport (HSL) which uses GTFS Realtime feeds. I believe you can adapt this repo to other GTFS feeds with minor modifications, if you are not living in Finland.

Below you can also see how the HSL clock shows service alert on an earlier version (direction names couldn't scroll yet).

If you're interested in controlling this clock with Home Assistant, I include my HA configuration here as well.

Great thanks to Edd Abrahamsen-Mills @eddible for his TFGM Metrolink Clock project inspiration https://github.com/eddible/tfgm-tram-clock.

Features

• Realtime public transport (metro/bus/tram) timetables.
• Realtime service alerts.
• Scroll longer station names.
• Support up to 4 destinations.
• Animations for funsy.
• Support 60 fps.
• Utilize quad-core Raspberry Pi models.
• API handlings for realtime data.

Used hardware

• Hyperpixel 2.1 Round
• Mounting Screws - Optional
• Raspberry Pi Zero 2 WH
• Micro SD Card - Use a high endurance card, cheap ones didn't last long in my experience.
• 3D Printed Case
• Angled micro USB cable - Optional
• USB power plug.

Guide

Flash your Micro SD Card

• Download Raspberry Pi OS 32-bit Buster Lite
• Download the Raspberry Pi Imager and install it on your computer.
• Launch it with your Micro SD Card plugged into your computer.
• Click Choose OS → select the OS file you downloaded earlier.
• Click Choose Storage and select your Micro SD card.
• Click Next and set following configurations on the next page.
  • Enable SSH → Use password authentication.
  • Set username and password → Leave the username as pi (if you must change it, you'll need to update transport_time.sh) but set a password.
  • Configure wifi → Enter your Wi-Fi details.
  • Save when you're done.
• Click Write and wait for the OS to be written to your SD Card
• Insert it into your Pi Zero 2 W, connect it to power and give it a few minutes to complete the first boot.

Get your stop and route ids

• Get your stop and route ids from here https://transitfeeds.com/p/helsinki-regional-transport/735/latest/stops. You'll need them for configuration.
• The API endpoints in this repo are taken from here https://hsldevcom.github.io/gtfs_rt/

Installing the software

• SSH into your Pi.

• Disable swap to reduce the SD card wear and also speed up system response time

  sudo dphys-swapfile swapoff
  sudo dphys-swapfile uninstall
  sudo systemctl disable dphys-swapfile
  

  Check whether swap is removed completely with this command free

• Install git:

  sudo apt-get update
  sudo apt install git -y
  

• Install the display driver then reboot:

  git clone https://github.com/pimoroni/hyperpixel2r
  cd hyperpixel2r
  sudo ./install.sh
  sudo reboot
  

• Download the code and move into the folder:

  git clone https://github.com/mikenhu/hsl-clock
  cd hsl-clock
  

• Install required libraries:

  sudo apt install python3-pip -y
  sudo pip3 install -r requirements.txt
  sudo apt-get install libsdl2-mixer-2.0-0 libsdl2-image-2.0-0 libsdl2-ttf-2.0-0 -y
  

• You can now configure your config file with your own details. Run this command:

  • nano config.ini

  • Edit the file as you wish.

    • URLs: HSL API endpoints.
    • Language: HSL has three options: "en", "fi", or "sv".
    • Number of timetable rows you want to have (up to 3 rows).
    • Insert your metro/bus/tram stops (from 1 up to 4 destinations). When you have more than 2 stops, the timetable row is limited to 1.
      • stop_id: one stop id per entry.
      • direction_name: self-naming due to HSL data does not include the head sign names.
      • direction_id: supposedly 0 is inbound, 1 is outbound. Unused at the moment.
      • route_id: can contain multiple routes per entry.

  • The content should be formatted like this:

    [HSL-CONFIG]
    trip_update_url = https://realtime.hsl.fi/realtime/trip-updates/v2/hsl
    service_alerts_url = https://realtime.hsl.fi/realtime/service-alerts/v2/hsl
    language = "en"
    time_row_num = 2
    stops = [
              {
                "stop_id": "1541602",
                "direction_name": "Kivenlahti",
                "direction_id": 1,
                "route_id": ["31M1"]
              }, {
                "stop_id": "1541601",
                "direction_name": "Vuosaari",
                "direction_id": 0,
                "route_id": ["31M1", "31M1B"]
              }
            ]

  • Once done, press CTRL+X → Y → Enter

• Next we'll set the script to launch at start up. Run these commands:

  sudo cp transport_startup.sh /usr/bin
  sudo chmod +x /usr/bin/transport_startup.sh
  sudo nano /etc/rc.local
  

• A text editor will open in your terminal window. Use your arrow keys to move to the bottom of the file and create a space above exit 0 and enter this:

  bash transport_time.sh &>/dev/null
  # Disable the LED when you boot your Pi Zero 2 W to prevent light leak
  echo none | sudo tee /sys/class/leds/led0/trigger
  echo 0 | sudo tee /sys/class/leds/led0/brightness

• To save your changes, press CTRL+X → Y → Enter

• That's it for the software. You can run it as is. Or...

Add Pi controls in Home Assistant

• Having the LCD always on is bad, I decided to integrate this HSL clock into my home assistant setup.

• In HA, you can execute CLI commands to control your Pi with command line and shell command integrations.

Access your Pi from Home Assistant

• Use the Advanced SSH & Web Terminal community add-on on HA. Make sure Protection mode is off.

• Create folder to store the public key

  mkdir /config/.ssh
  

• Create a public key.

  ssh-keygen -t rsa
  

• Tell it to store it in /config/.ssh/id_rsa. Do not set a password for the key!

• Copy the created key to your Pi.

  ssh-copy-id -i /config/.ssh/id_rsa pi@[Host]
  

• Copy known_hosts from /root/.ssh to /config/.ssh/ folder.

  cp /root/.ssh/known_hosts /config/.ssh/
  

• Try to ssh into your Pi from your HA and see if it works without a login.

  ssh -i /config/.ssh/id_rsa pi@[Host]
  

• Make sure the correct permissions are set on the ~/.ssh directory and the ~/.ssh/authorized_keys file on the Pi.

  ssh -i /config/.ssh/id_rsa pi@[Host] "chmod 700 ~/.ssh && chmod 600 ~/.ssh/authorized_keys"
  

Create the switches and buttons in Home Assistant

Copy my config below into your configuration.yaml file and make it match your network setup.

• Command line

command_line:
  - switch:
      name: Transport Dashboard Screen
      unique_id: transport_dashboard_screen
      command_off: 'ssh -o HostKeyAlgorithms=+ssh-rsa -o PubkeyAcceptedKeyTypes=+ssh-rsa -o UserKnownHostsFile=/config/.ssh/known_hosts -i /config/.ssh/id_rsa -q pi@[Host] "sudo -E sh -c ''echo 1 > /sys/class/backlight/rpi_backlight/bl_power''"'
      command_on: 'ssh -o HostKeyAlgorithms=+ssh-rsa -o PubkeyAcceptedKeyTypes=+ssh-rsa -o UserKnownHostsFile=/config/.ssh/known_hosts -i /config/.ssh/id_rsa -q pi@[Host] "sudo -E sh -c ''echo 0 > /sys/class/backlight/rpi_backlight/bl_power''"'
      command_state: 'ssh -o HostKeyAlgorithms=+ssh-rsa -o PubkeyAcceptedKeyTypes=+ssh-rsa -o UserKnownHostsFile=/config/.ssh/known_hosts -i /config/.ssh/id_rsa -q pi@[Host] "cat /sys/class/backlight/rpi_backlight/bl_power"'
      value_template: '{{ value == "0" }}'

• Shell command

shell_command:
  restart_pi: 'ssh -o HostKeyAlgorithms=+ssh-rsa -o PubkeyAcceptedKeyTypes=+ssh-rsa -o UserKnownHostsFile=/config/.ssh/known_hosts -i /config/.ssh/id_rsa -q pi@[Host] "sudo reboot"'
  shutdown_pi: 'ssh -o HostKeyAlgorithms=+ssh-rsa -o PubkeyAcceptedKeyTypes=+ssh-rsa -o UserKnownHostsFile=/config/.ssh/known_hosts -i /config/.ssh/id_rsa -q pi@[Host] "sudo shutdown -h now"'