Big Clock on a Small Budget

A cost-effective solution to display a large, readable clock in a fire station using repurposed hardware.

Juho Torkkeli

Juho Torkkeli

1/19/2025 · 2 min read

Large digital clock and date display on a monitor, showing 11:07 and 19.01.2025.

Overview & Background

Our fire station needed a large clock visible from across the hall. While commercial LED clock options were considered, they turned out to be too expensive. Fortunately, we had an extra large display and a Raspberry Pi available. I was tasked with investigating whether we could use these to build a custom clock and save money in the process.

Issue addressed: Providing a highly visible time display for the fire station while minimizing cost.


Development Process

To begin, I explored how a Raspberry Pi could be used to display the current time in a simple, user-friendly way and boot directly into that mode. I found a lightweight OS distribution called FullPageOS that allows the Pi to launch into a full-screen browser on startup.

I discovered that the displayed page could also be hosted locally, which simplified the setup and made the system more robust. I then designed a minimal interface that prominently shows the current time and date.

As the project progressed, I refined the layout slightly and added a night mode feature that activates automatically based on the time of day.


Outcome

  • A simple and clear fullscreen display showing the current time and date.
  • Automatically starts on boot with no user interaction.
  • Day/night mode changes based on time.
  • Cost 0€

Technologies & Tools

  • Raspberry Pi
  • HTML
  • CSS
  • JavaScript
  • FullPageOS