Precision Clock Mk IV
The mitxela Precision Clock Mk IV is the latest development in my quest to build the best wall clock.
GPS synchronised, millisecond display. Brightness adjusts automatically, and the display doesn't flicker even when filmed at high speed (tested at 25,000FPS).
The precision is tied to the accuracy: if the GPS signal is lost, and the time starts to drift, the last few digits will progressively disappear, and only come back when it re-syncs.
Auto timezone. The clock contains an on-board world map and timezone database. Using the GPS coordinates and a point-in-polygon algorithm, the clock calculates the correct local time (including daylight saving) without any configuration, and will automatically update when carried across timezone boundaries. The USB port presents a mass storage device, so when the maps or database change, updating them is as simple as drag-and-drop.
Multiple display modes are supported, including ISO-ordinal, ISO-week, Unix timestamp, Julian date, and a high-precision countdown mode. For a full list of modes, see the user manual. More display modes may be released in future firmware updates, which again, are as simple as drag-and-drop with the USB port.
Finally, the clock can fold in half, to become more compact. The top display automatically rotates, and a small magnet holds it together. Using the clock as a clapperboard is possible, but not advised.
In the unfolded position, the clock is 53cm (21 inches) wide. Folded, it's about 27cm (10.5 inches) wide and 7cm (3 inches) tall.
This is only a brief summary – for the full story, head to the project page.
The clock is available both as a kit, and fully assembled. The kit has all of the surface mount parts pre-soldered, for an overview see the instructions here.
- US orders will be subject to a 10% tariff. This will be pre-paid and collected at checkout.
- Orders from Europe will be subject to import duty when they arrive (VAT + handling fee). I am hoping to be able to pre-pay this eventually, but I'm still working on it.
(2025-09-26) The second batch of clocks is now available! The board has been revised so it's slightly easier to solder, and it now has a USB-C port and RoHS-compliant light sensor.
Precision Clock Mk IV Kit: £250 GBP
Precision Clock Mk IV fully assembled: £350 GBP
Please remember that I am just one person handling all of this so I can only make small batches.
If you want to be notified when more kits are available, you can put your email address into this form and I will message when more are available: