Tair Keyboard

The Tair Keyboard is a fully wireless, split mechanical keyboard project designed around an nRF52840 controller (nice!nano v2) and the ZMK firmware stack. It is intended as a practical open-hardware replacement for expensive, closed-source products with documentation and design files published for reuse and modification.

Project source (design files, firmware, and BOM) can be found here.

• Split layout with a column-staggered main cluster and dedicated thumb keys.
• Total key count and exact geometry are defined in the PCB + switch footprint placement files in the repo.

• Controller: nice!nano v2 (nRF52840)
• Firmware: ZMK (Zephyr-based)^[1]

ZMK is used to support wireless operation and split keyboard configurations, with customization handled through the ZMK configuration/build process.

• ZMK split keyboard feature reference

• Soldering iron + solder + flux
• Tweezers, side cutters
• Multimeter (continuity / shorts check)
• USB cable for flashing
• (Optional) hot air / rework tools depending on assembly choices

• Use the design files in the repo: PCB folder
• Export Gerbers and order from a PCB fab of your choice.

• Solder the switch footprints and required electronics per the schematic / PCB silkscreen.
• Before powering: do a continuity/short check on power rails and around the controller header pins.

Before flashing, modify the firmware configuration for the key layout of your choice and build new firmware.

• Edit your keymap: ZMK keymaps are defined in a .keymap file (layers + bindings/behaviors). Update the layout/layers to match your preferences.
• Build the firmware (recommended: GitHub Actions):
  • Use the standard ZMK workflow: create/update a ZMK user config repository, set the appropriate build targets in build.yaml, and commit your .keymap / .conf changes.
  • Push changes to trigger a build and download the resulting .uf2 artifacts.
• OR build locally: Use the ZMK CLI / local build tooling if you prefer building on your machine.

The nice!nano v2 uses the Adafruit nRF52 UF2 bootloader workflow.

• Enter bootloader mode (UF2 drive).
• Drag-and-drop (or copy) the compiled .uf2 firmware file to the NICENANO drive.

• Pair the keyboard over Bluetooth LE to your host device.
• Verify each half is communicating correctly (split behavior depends on your ZMK configuration).
• Validate matrix scanning (no stuck keys, no ghosting, correct keymap behavior).

• V2 mechanical iteration focused on improved ergonomics and a more compact footprint.
• Optional build variants (e.g., alternate thumb clusters, switch/socket options) depending on design direction.

• If using LiPo batteries, follow safe charging/handling practices and avoid short circuits.
• Verify polarity and continuity before first power-on.