Improved HACK LABS MatrixClock firmware with accurate timekeeping, flexible display settings and Home Assistant integration.
In everyday use, the clock stays very closely aligned with NTP time, maintaining excellent accuracy between synchronisations.
Check your hardware first: this firmware is for the matching ESP8266 MatrixClock board with 4 MB flash. It is not a general-purpose firmware for other ESP8266 clocks.
- Automatic clock drift calibration using NTP: learns the clock's quartz oscillator error rate and automatically adjusts its timing to stay closely aligned with NTP between synchronisations. The web page shows learning progress and the correction in use.
- More robust time synchronisation: checks NTP replies, filters uncertain measurements and retains the last good correction. The battery-backed DS3231 remains available when network time is unavailable.
- Flexible timezone and DST settings: choose from 40 regional presets, disable seasonal changes or enter a custom POSIX rule.
- More display control: orientation, brightness, separators, animations and date scrolling, with display changes applied without a reboot.
- Added stopwatch: normal and hundredths-of-a-second modes, recent results and extended timing, controlled using the clock's existing buttons—no additional hardware required.
- MFB: the multi-function button shows the date, controls the stopwatch, cancels messages and provides a warning-protected factory reset using the existing button. See button controls.
- A rebuilt web interface: separate settings and live status, a display preview, uptime, NTP diagnostics and calibration information.
- Home Assistant integration: send scrolling messages with a selectable number of passes and read the RTC's internal temperature through a local HTTP API.
- Simpler setup and maintenance: phone-based Wi-Fi setup, optional web login, factory reset, web firmware updates and configurable restart behaviour.
The calibration corrects the software clock, not the DS3231's hardware oscillator. See timekeeping and settings for how calibration and RTC backup work.
Start here: download, update and set up your clock →
No compiling or source editing is needed. Download MatrixClock_Improved_v3_1_2_OTA.bin from the release assets. The same file supports a web update or a clean USB installation.
Example MatrixClock listing on AliExpress.
Buying reference only: confirm the matching HACK LABS ESP8266 board with 4 MB flash. Listings and hardware revisions can change.
Set your Wi-Fi, timezone, NTP server and display preferences in the browser.
For automation, follow the Home Assistant and API guide. Keep the clock on a trusted local network: its web interface uses HTTP, not HTTPS. Do not expose it directly to the internet.
- Timekeeping, calibration and timezone settings
- Changes by version
- Build from source and developer checks
- Report a problem
Based on the original HACK LABS MatrixClock v2.2 package, modified and maintained by Steve Madden. Original attribution remains in the source.
Source and firmware are distributed under GNU GPL v3, without warranty. Installing firmware is at your own risk.