tmk_keyboard/converter/usb_usb

USB to USB keyboard protocol converter

See for detail and discussion. https://geekhack.org/index.php?topic=69169.0

Hardware requirement

There are two options.

TMK USB-USB Converter

You can buy a fully assembled converter from me here.

https://geekhack.org/index.php?topic=69169.0

Arduino Leonardo + Circuit@Home USB Host Shield 2.0

Buying Arduino Leonardo and USB Host Shield 2.0(from Circuit@home) will be better, you won't need even soldering iron.

http://arduino.cc/en/Main/ArduinoBoardLeonardo 
https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino-assembled/

Other compatible boards like Arduino's Shield will also work well but I think Sparkfun's needs to be modified.

http://arduino.cc/en/Main/ArduinoUSBHostShield
https://www.sparkfun.com/products/9947

Also Pro Micro 3.3V(not Mini) or Teensy with mini host shield will work with some fixes on signal/power routing.

https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-for-arduino-pro-mini
https://www.sparkfun.com/products/12587
https://www.pjrc.com/teensy/td_libs_USBHostShield.html

Build firmware

Build.

$ git clone https://github.com/tmk/tmk_keyboard.git
$ cd tmk_keyboard
$ git submodule init
$ git submodule update
$ cd converter/usb_usb
$ make

And Program converter. Push button on TMK converter and just run this.

$ make dfu

In case of Leonardo push reset button then run command. Serial port name(COM17) depends your system. On Linux I got /dev/ttyACM0.

$ DEV=COM17 make program
or
$ avrdude -patmega32u4 -cavr109 -b57600 -Uflash:w:usb_usb.hex -PCOM17

Limitation

Only supports 'HID Boot protocol'.

Note that the converter can host only USB "boot protocol" keyboard(6KRO), not NKRO, it is possible to support NKRO keyboard but you will need to write HID report parser for that. Every NKRO keyboard can have different HID report and it is difficult to support all kind of NKRO keyboards in the market.

Keymap editor

You can editor keymap and download firmware with web brwoser.

• http://www.tmk-kbd.com/tmk_keyboard/editor/unimap/?usb_usb

Update

2014/12/11 Added Hub support(confirmed with HHKB pro2) 2016/09/10 Unimap editor support 2016/10/18 Fix LED state at startup 2017/05/xx Fix startup code for FC660C(3eae475) 2018/02/xx Add Korean and Brazilian specific keys(ab6ddac,b2fa0ffa) 2018/07/xx Fix startup issue(c2ce617) 2018/10/xx Use fixed LUFA stack and update USB_Host_Shield_2.0 2019/09/18 Add BTLD(bootlader jump) key to unimap

Resource

USB Host Sheild 2.0 https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-for-arduino-pro-mini USB Host Sheild 2.0 source https://github.com/felis/USB_Host_Shield_2.0 Arduino USB Host Shield(with bootst converter) http://arduino.cc/en/Main/ArduinoUSBHostShield Arduino source https://github.com/arduino/Arduino/hardware/arduino/{cores,variants} Initial release of TMK USB-USB converter https://geekhack.org/index.php?topic=33057.msg653549#msg653549 http://deskthority.net/workshop-f7/is-remapping-a-usb-keyboard-using-teensy-possible-t2841-30.html#p74854 Arduino-based hardware keyboard remapper - Colemak forum http://forum.colemak.com/viewtopic.php?id=1561 Teensy + Host Shield http://www.pjrc.com/teensy/td_libs_USBHostShield.html