Skip to content

Warning

This project is incomplete. I've hit a major roadblock and haven't had the time to return to it! I do plan on completing this project sometime...

Progress

I've brought this project back and started working on it again! See below for details.


Alarm Clock

Overview

A DIY alarm clock using a huge custom LED display salvaged 7" LCD displays from old intercom devices, ESP32, wireless snooze button, and a plethora of misc. sensors. It also displays the day & month, indoor/outdoor temperature, weather, and humidity, alongside custom audio output.


Hardware

  • ESP32 microcontroller, directly soldered to mainboard
  • DS3231 high-precision timekeeping
  • PCM5102A stereo output for alarms (no preamp)
  • AHT20 temperature and humidity sensor
  • BH1750 ambient light sensor for auto-dimming
  • well-documented LMR36520ADDAR buck IC for a stable logic rail
  • Custom PCBs throughout
  • 7" LCD (salvaged from intercom)

Undecided

Encountered severe issues with the intercom OS that would take too long to reverse-engineer. I'm considering moving towards a small projector rather than an LCD...

  • Radio transmitter/receiver for snooze button

Features

  • NTP time sync over WIFI, with DS3231 as backup for wifi blackouts
    • Adjusts for daylight savings time
  • 200mmx400mm digits so I can see the time without my glasses in bed
  • 15 16-segment displays showing the date, driven off 5 chainable custom PCBs
  • 2x touchscreen TFT LCDs displaying the indoor/outdoor climate
    • custom UI for changing user preferences
    • AHT20 for indoor temperature and humidity
  • Auto-dimming based off ambient brightness with BH1750
    • positioned to minimize photonic feedback
  • RF receiver for wireless snooze feature/remote
  • Low-power mode with solid state relay
  • Custom alarm sounds with pcm5102a
  • 12v trigger feature for external alarms

Build Notes

TODO

Add wiring diagrams, code snippets, images, and format this page properly


Changelog

September 9, 2026 Latest
Added

Updated this page with the current state of things. Full documentation formatting deferred until project completion. A private progress log is being kept.

Added

Laser-cut the plexiglass front panels, spray-painted their backs to make them completely opaque

Added

Obtained and cut lumber for frame

Added

Several firmware demos for a breadboarded mainboard

Added

Continue designing the mainboard. Progress will be slow due to classes possessing a higher priority!

March 13, 2026
Added

Ordered addressable LED strips.

Changed

The power requirements for this project. Obtained a 12V 10A (120W!) PSU.

Added

Obtained a 12V to 5V automotive buck since most of the components run off 5V.

Added

Plans to use small buck for ESP32 and other controllers.

Added

Full inkscape draw-up of laser cuts needed in said plexiglass.

Added

Ordered plexiglass (some opaque, and some translucent) for front face & shine-thru cutouts.

Added

Started 3d printing light tubes & led backing holders.

March 11, 2026
Changed

Brought this project back from the dead!

Removed

Intercom LCD integration attempt.

Added

Plans for a custom giant LED wall.

Added

Plans for a segmented display showing the date.

Added

Started sourcing 16 segment displays for date display.

Added

Plans for a small LCD displaying the outdoor temperature.

Added

Plans for a small touchscreen for editing user configuration.

Added

Plans for RF receiving capabilities.

Added

Plans for self-power on/off with solid state relay.

December 5, 2025
Deprecated

Ran head-first into a brick wall with the intercom display.

Removed

Shelved this project indefinitely.

November 3, 2025
Added

Initial idea for this project.

Added

Started poking Claude for help hacking the Intercom display.