Custom bluetooth keyboard

Bluetooth conversion of a Kinesis contour keyboard to a bluetooth keyboard.

Brainstorming

Available approaches

Options	Pros	Cons
USB HID to bluetooth adapter	No modification of the keyboard necessary	USB HID host chips are uncommon and expensive Programming USB HID host may be complicated PS/2 version of keyboard may or may not have USB output (though there are USB related markings on the PCB)
PS/2 to bluetooth adapter	Simpler to decode than USB HID Any microcontroller can do it	USB version of keyboard may or may not have PS/2 output
Custom replacement keyboard controller with integrated bluetooth	Getting data directly from button matrix is likely simpler than decoding some other protocol Opportunity to add extra features Likely better battery life	Kinesis keyboards have some advanced programmability - reimplementing that on a custom controller could take some time Requires interfacing with the key matrix directly which either requires special connectors or soldering to the key matrix

Features

• Bluetooth module might have HID and audio capabilities
  • Use keyboard as audio extender - include a headphone port in keyboard
  • Kinesis has a key recognition click speaker built in which can be hard to hear when listening to music, but might still annoy others
    • Overlay key click sound over bluetooth audio signal
• USB interface for charging
  • disable bluetooth while charging and instead use the USB connection
• Saving, editing, and uploading custom keyboard layouts to the keyboard from the computer
  • Cross platform application

Reference

• Development example using Bluegiga WT12
• WT12 breakout boards - supposedly open hardware, but I haven't seen the layout files yet
• WT12 module
• Custom bluetooth IBM Model M using a salvaged bluetooth module from a mini keyboard - salvaged PCB
• Custom bluetooth IBM Model M using a salvaged bluetooth module from a mini keyboard - custom PCB
• Custom bluetooth HHKB using the WT12