Still on the same mission: make this wallet last. Two more parts got upgraded for the first build — the brain went industrial-grade, and the display connector is gold.
An industrial-grade brain
For the first build we're moving the microcontroller to the industrial temperature grade: the STM32F205RET7, rated from -40 °C to +105 °C — up from the +85 °C part we started with. A wallet might sit in a hot car, a safe, or a drawer in a tropical country; industrial-grade silicon keeps working where consumer parts start to drift. And it's still the same open, general-purpose STM32 — no secret chip, just the tougher temperature bin.
Gold where it counts
The screen connects through a thin flex cable, and its connector is exactly the kind of small part that quietly corrodes over the years. We chose a Hirose FH34 connector with gold-plated contacts. Gold doesn't oxidise, so the connection stays clean and reliable for the whole life of the device — not just the first year.
Small parts, long life
Nobody puts the temperature grade of a microcontroller or the plating on a connector on a product page. But those unglamorous choices are exactly what decides whether a device still works in fifteen years. We'd rather spend our attention there than on another feature nobody asked for.
More from the bench soon. If you want to see the industrial build in person, we'll have the prototype at Bitcoin Thailand Conference 2026.