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Black rectangular numpad kit PCB with per-key RGB LEDs and Type-C port

Corn Electronics

Corn Electronics GK21S 32-bit Gaming Keyboard Numpad Kit Bluetooth 5.1 750mAh

SKU CH-Y9NA-GPZDV

A 21-key numpad kit with a 32-bit MCU, 8 MB flash, hot-swappable Kailh sockets and per-key RGB driven by a 16.8 M-colour chip, offering Bluetooth 5.1 or wired Type-C use from a 750 mAh battery

  • Key SwitchNo
  • Keyboard ColorBlack

Key Switch Type No

Keyboard Color Black

  • 32-bit MCU delivers responsive keystroke processing
  • 8 million colour RGB lighting with per-key control
  • Bluetooth 5.1 and Type-C USB dual-mode connectivity
  • Hot-swappable Kailh sockets accept Cherry, BOX or Gateron MX switches
  • 750 mAh battery powers extended wireless sessions

Compact Numpad Kit

The Corn Electronics GK21S is a 32-bit mechanical numpad kit designed for custom keyboard builders. It ships without switches so you can choose MX-compatible three-pin or five-pin variants. A hot-pluggable Kailh socket makes swapping switches solder-free. The PCB also supports plate-mount stabilisers for larger keys.

DIY Enthusiasts Only

This kit suits hobbyists who enjoy assembling their own typing experience and want per-key RGB with 16.8 million colours. It is not for buyers who need a fully assembled, ready-to-use numpad. It also does not suit users who require dedicated media keys or a built-in wrist rest.

Dual-Mode Connectivity

The board connects via a Type-C USB cable or Bluetooth 5.1 for wireless freedom. A 750 mAh lithium battery powers the wireless mode. The 32-bit MCU and 8 MB flash store three programmable layers and macro recordings. Music-rhythm lighting reacts to audio input for visual feedback.

Highlights

  • 32-bit MCU delivers responsive keystroke processing
  • 8 million colour RGB lighting with per-key control
  • Bluetooth 5.1 and Type-C USB dual-mode connectivity
  • Hot-swappable Kailh sockets accept Cherry, BOX or Gateron MX switches
  • 750 mAh battery powers extended wireless sessions

Specifications

Key SwitchNo
Keyboard ColorBlack

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Questions about this item

How often will the 750mAh battery need recharging during daily Bluetooth 5.1 use?

The 750mAh battery charges via Type-C; actual runtime depends on LED brightness and Bluetooth activity.

What limits the 32-bit MCU and 8M Flash when running complex macros continuously?

The 32-bit MCU and 8M Flash handle three programmable layers and macro storage without a stated throughput ceiling.

How much heat or noise does the PCB produce when RGB LEDs run at full 16.8M colour all day?

The PCB uses SMD LEDs and a 256×256×256 driver chip; it has no moving parts so noise is negligible and heat stays low.

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