Dual Encoder Number Pad

A number pad with an extra row with 2 encoders and 2 keys. It is useful to use with a keyboard that doesn't have a number pad or along with a laptop. I used the encoders for volume or arrow keys to scrub through YouTube videos.

Parts:

• 1x RP2040 Pro Micro (link)
• 21x 1n4148 diodes (link)
• 2x ec11 encoders (link I used these from amazon but there are much cheaper ones from AliExpress)
• 2x encoder knobs (my encoders came with knobs but you can also print your own)
• 19x MX Key Switches (I used Akko Lavender Purples) (link [this has 45 switches per box])
• 19x MX Keycaps (16 1u keycaps and 3 2u keycaps) (Joe Scotto's ScottoCaps are good if you want printed ones)
• 3x 2u stabilizers (I didn't use any and it works. The 2u keys are just kind of wobley and might bind if you press on the edge.)
• Bare solid copper wire
• Heatshrink (to insulate the solid wire at intersections) (link)
• Stranded wire (to connect to the mcu. I used the wire from an ethernet cable)
• 6x m2 x 8mm standoffs (link I used these from amazon but there are much cheaper ones from AliExpress)
• 12x m2 x 6mm bolts

After printing the case and plate, you will need to cut through the sacrificial bridging in the screw holes with a knife.

Wiring:

The columns are connected to …

The rows are connected to …

I highly recommend this video for the actual wiring of the board and explanation of how things work.

Firmware:

I made my firmware in QMK. You can also just install CircuitPython and use KMK POG which will also let you set up the keyboard graphically.