MiniPad

minipad

a 3x3 macropad for shortcuts, built for hackpad. 9 keys, a rotary encoder, per key rgb, and a 0.91" oled that shows a clock and a spinning globe.

the pad

rendered from the actual case and board files in this repo, not a mockup. photo of the real thing goes here once it's printed and soldered.

schematic

pcb

96.38 x 90.90mm, 2 layers. chamfered corners, and 4x m3 mounting holes on an 88.226 x 82.748mm rectangle for a sandwich case.

the 9 sk6812mini-e leds are reverse mounted. they sit in milled slots in the board and shine up through the switches, so the lighting is per key rather than underglow.

case

open the assembly in onshape

a sandwich: 1.5mm switch plate on top, the pcb in the middle, tray bottom underneath. 102.38 x 96.90mm overall, 16.6mm tall closed.

the pcb rests on four bosses at 10mm, which leaves a 7.5mm cavity under the board for the reverse mounted leds and the xiao. m3 heatset inserts drop into the bosses from above, and four m3 screws through the plate into those inserts hold the stack together. the only overhang is the usb-c slot in the side wall, which is a 7mm bridge.

production/Top.STEP and production/Bottom.STEP are the two printable parts. cad/Assembly.STEP is the whole thing put together, with the pcb in it.

oled

the globe is generated from real natural earth coastline data. 24 frames, made by projecting the land polygons onto a tilted sphere, so those are actual continents at 32x32 pixels.

bom

everything except the encoder knob comes from the standard kit.

keymap

the encoder does volume.

the three app launchers use windows taskbar shortcuts (win+1/2/3), so pin spotify, chrome and vs code to the first three taskbar slots and the top row works with no extra software.

clock

there's no rtc on the board and usb hid can't send the time, so the clock free runs from a timer and you set it by hand:

• hold the two top corner keys together to toggle set mode
• encoder adjusts minutes
• top left / top right keys adjust hours
• top middle exits

it resets to 00:00:00 whenever you unplug it, and drifts a few seconds a day.

pins

3x3 matrix, row2col. all 11 gpio are used, which is why the encoder's push switch isn't wired.

firmware

qmk. production/firmware.uf2 is prebuilt, so to flash it just double tap reset on the xiao and drag the file onto the drive that appears.

to build it yourself, drop firmware/ into qmk_firmware/keyboards/minipad/ and run:

qmk compile -kb minipad -km default

layout

pcb/         kicad source and the board step
firmware/    qmk source
cad/         assembled case model
production/  everything you need to build one: gerbers, the two
             printable case parts, and the prebuilt uf2
assets/      images for this readme