My next goal was to get a full macro pad working and since JLCPCB sends you always 5 PCBs as a minimum, there were still a few more rows with 4x1 Atoms left.

The assembly was labor intensive as I had to bake all PCBs first, solder them to the side connector and apply the fixes with some bodge wires:

Next, I extended my QMK firmware and got all diplays working (after some debugging) - Halleluja!

There were still some minor issues, not all displays worked trouble-free, extending the FFC is not easy :(

Even though my intention with the Atom's side-connectors was to make it easily buildable and affordable for everyone, it turned out quite some work. Maybe a ready made PCB would be worth a try...

Also my used MCU, the STM32F407 became unavailable, which made me think about alternatives.

Luckily the state of the RP2040 QMK branch looked already promising so that I decided to convert the macro pad to the RP Pico!