Tiny 40%
A 4x12 matrix the same size as the Gherkin Express TH and using the same 6x6mm tactile switches.
The switches are rotated so that the through hole pins are staggered allowing the switches to be placed closer together.
The power and activity LEDs from the Gherkin Express TH are removed. Instead the blue LEDs for V-USB voltage regulation are used as a power indicator, and a flickering activity indicator.
The miniature 16MHz crystal is also used as on the second version of the Gherkin Express TH.
There is only one decoupling capacitor instead of the usual 2.
The 1mm thick top PCB has legends in the copper layer.
The two blue LEDs on the corner, D- on the left and D+ to the right. D+ is always on while connected to USB. D- flickers when data is being transmitted.
The two red switches are the RESET and USBASP switches for entering the V-USB bootloader.
Everything fits with 4mm M2 spacers. Construction is the same as with the Gherkin Express TH.
Same credit card size as the Gherkin Express TH. It shares the same bottom PCB. Screw holes are in the same positions.