November 2, 2026Story

Making LogCase Full Colour

The final LogCase Full Colour circuit board fitted inside the case

Mass production of LogCase Full Colour is finished. Before we move on, here is a look back at how it was made. It was far from simple.

Harder than four colours

A full-colour E-Paper panel needs much more power and much more data than the four-colour panels in our earlier cases. It asks more of NFC energy harvesting than the technology was first designed to give.

What looked impossible at first became nearly a year of research and development, all done in house.

Six circuit boards

Six prototype circuit boards for LogCase Full Colour, from green test boards to the final black board — Prototype boards, from the first green test boards to the final black one.

We went through six versions of the circuit board, and refined the firmware and the app more times than we can count. Things failed in ways we did not expect. Sometimes the display refreshed wrongly. Sometimes the picture broke up halfway through. Every time we solved one problem, another appeared.

There were moments we thought about giving up.

Designing the board, soldering a prototype, and testing the panel's colours.

Enough power for every colour

The hardest part was power. Taken straight from the NFC field, a circuit gets about 20 to 70 milliwatts, and the voltage drops just when the panel needs the most. That is not enough for a full-colour refresh.

Our circuit stores spare energy in a capacitor while the picture is being sent, then uses it to keep the voltage steady through the refresh, with more than 200 milliwatts when it counts. We also made the image data a third smaller, from 120 KB to 80 KB, so the transfer is shorter. You can read more in our patent article.