1WOAmwkS22

Low-cost numeric keypad

Overview

Just search for "keyboard switches"; both three-pin and five-pin switches are compatible, with five-pin switches being more stable.

I bought 10 red switches using a Taobao sign-in bonus for 1.92 yuan, equivalent to 4 for 0.77 yuan each.

The keycaps were borrowed from my roommate, so they were basically free. The CH552G uses Uxin Electronics
WS2812B LEDs, which cost 1.74 yuan each. They are reverse-mounted LEDs, 20 for 7.76 yuan, equivalent to 4 for 1.5 yuan each.

Resistors and capacitors cost only a few cents each. The software code is in the attachment.

Design Files

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Update:2026-03-27 18:45:32

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