Infomation on ps2avrU and ps2avrGB

  1. ps2avrU  

        1) What is ps2avrU?

a. Firmware supporting both USB and PS/2

b. Combination of 2 firmwares, “ps2avr”(for ps/2) and “dulcimer”(for USB)

c. Link for projects


        2) Difference between USB and PS/2 interfaces

a. USB

  • Supporting 6+1 simulataneous key input
  • Supporting normal speed for key repeat

b. PS/2

  • Supporting unlimited simultaneous key input
  • Supporting fast speed for key repeat



       3) How to change interface

a. Basically it changes automatically

b. If you want to change it manually

  • to USB : While pressing “U” key, connect the keyboard to USB port.
  • to PS/2 : While pressing “P” key, connect the keyboard to PS/2 port.

c. If you want to reset : While pressing “U”+ “P”, connect the keyboard to port



       4) Interface Signal

a. You can tell by flashing count of CapsLock/NumLock LED

  • 1 time : recognizing PS/2
  • No flashing : recognizing USB
  • Continuous flashing : in the process of recognizing



      5) Basic functions

a. Supporting Full LED

b. Providing interface to change LED mode : While pressing “ESC”, press “Caps Lock”  for specific times

  • 1 time : LED off
  • 2 times : Fading
  • 3 times : LED on
  • 4 times and then any key down :  Getting brighter
  • 5 times and then any key down : Getting darker

c. Setting full LED brightness using macro

  • KEY_LED_UP : getting brighter
  • KEY_LED_DOWN : getting darker

c. Mapping keys for brightness

  • A.87 and MX-mini series : FN + – / FN + =
  • Thumb series : FN + R Alt/ FN + R Ctrl

d. 4-Layer Key Map

  • 1 : Normal
  • 2 :  FN
  • 3 :  FN2/FN3

e. Scroll Lock LED signal

  • There is no special signal for Scroll Lock LED. But you can tell by seeing Caps Lock LED flashing when it turns on or off(1 tiem for off, 2 times for on).
  • One of Firmware files named “SL_apart” shows Scroll Lock LED in MCU PD6 pin.
  • Sleep Mode : When system ends, keyboard enter sleep mode turning LED off when connected through USB.


          6) Key Mapping

– Link :



        7) Hardware and Quick Macro

– Link :



        8) Quick Swap

a. “Swap” means altering between “alt” and “GUI”

b. Press “alt” + “GUI” together for 5 seconds.



        9) Special Keys

<Lock Key/Win Key>

  • Lock Key : prevents input form all the keys.(toggle)
  • Lock Win : block left/right window key press.(toggle)


<Lazy FN/FN2>

  • If you set lazy FN  option  on, you can’t change layer.
  • This option can be set in the hardware key mapper menu.


<Shift + Esc = ~>

  • In mini keyboard, entering “~” is difficult. So you can do that with “Shift + ESC” key.
  • In Key Mapper menu, change “esc to ~” option to “on”


10)  Dual action key

  • This action is triggered by combining a several key functions.
  • If you don’t combine other keys, it is act as a normal function key like Lang key.
  • You can add this functions to the keys like FN, FN2, Ctrl, alt, shift.
  • For exmaple, if you press other key while pressing the key “KEY_FN_HANGLE” , then it is act as “FN” key.
    But solely this key act as Lang(hangle<->eng) key.
  • Dual Action key list


   11) how dual action key acts

  • You have to wait 0.5 second after pressing it to make it act as Dual Key.
  • If you combine other keys, it act as Dual key without 0.5 second waiting.
  • If you want to change the language with only one key(Lang key), you have to press down and up in  0.5 second.


  1. ps2avrGB

        1) What is ps2avrGB

a. Supporting ps2avrU + RGB LED control

b. Supporting all functions BootMapper client provides.


        2) RGB LED

a. Provides the interface to change RGB LED color by using bootMapper client.

b. Mode Change : ESC + SHIFT + CapsLock or  LED MODE2

c. Changing of RGB key event mode : ESC + Ctrl + CapsLock or Ctrl + LED_MODE2

d. Setting brightness : SHIFT+KEY_LED_UP, SHIFT+KEY_LED_DOWN (The brighter RGB LED, the darker full LED)

Basic Key Mapping on the keyboard with F keys

  • LED MODE : FN+Caps lock
  • KEY_LED_UP : FN + =
  • KEY_LED_DOWN : FN + –

e. Basic Key Mapping on the keyboard without F keys

  • KEY_LED_UP : FN + H


You can see more about “bootMapper Client” at

For the B.pad keymap, visit “”