diff --git a/keyboard/hhkb/Makefile.tmk b/keyboard/hhkb/Makefile.tmk
new file mode 100644
index 00000000..d3730081
--- /dev/null
+++ b/keyboard/hhkb/Makefile.tmk
@@ -0,0 +1,129 @@
+#----------------------------------------------------------------------------
+# On command line:
+#
+# make all = Make software.
+#
+# make clean = Clean out built project files.
+#
+# make coff = Convert ELF to AVR COFF.
+#
+# make extcoff = Convert ELF to AVR Extended COFF.
+#
+# make program = Download the hex file to the device.
+#                Please customize your programmer settings(PROGRAM_CMD)
+#
+# make teensy = Download the hex file to the device, using teensy_loader_cli.
+#               (must have teensy_loader_cli installed).
+#
+# make dfu = Download the hex file to the device, using dfu-programmer (must
+#            have dfu-programmer installed).
+#
+# make flip = Download the hex file to the device, using Atmel FLIP (must
+#             have Atmel FLIP installed).
+#
+# make dfu-ee = Download the eeprom file to the device, using dfu-programmer
+#               (must have dfu-programmer installed).
+#
+# make flip-ee = Download the eeprom file to the device, using Atmel FLIP
+#                (must have Atmel FLIP installed).
+#
+# make debug = Start either simulavr or avarice as specified for debugging, 
+#              with avr-gdb or avr-insight as the front end for debugging.
+#
+# make filename.s = Just compile filename.c into the assembler code only.
+#
+# make filename.i = Create a preprocessed source file for use in submitting
+#                   bug reports to the GCC project.
+#
+# To rebuild project do "make clean" then "make all".
+#----------------------------------------------------------------------------
+
+# Target file name (without extension).
+TARGET = hhkb_tmk
+
+# Directory common source filess exist
+TOP_DIR = ../..
+
+# Directory keyboard dependent files exist
+TARGET_DIR = .
+
+
+# List C source files here. (C dependencies are automatically generated.)
+SRC +=	keymap.c \
+	matrix.c \
+	led.c
+
+CONFIG_H = config.h
+
+
+# MCU name
+#MCU = at90usb1286
+MCU = atmega32u4
+
+# Processor frequency.
+#     This will define a symbol, F_CPU, in all source code files equal to the
+#     processor frequency in Hz. You can then use this symbol in your source code to
+#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
+#     automatically to create a 32-bit value in your source code.
+#
+#     This will be an integer division of F_USB below, as it is sourced by
+#     F_USB after it has run through any CPU prescalers. Note that this value
+#     does not *change* the processor frequency - it should merely be updated to
+#     reflect the processor speed set externally so that the code can use accurate
+#     software delays.
+F_CPU = 16000000
+
+
+#
+# LUFA specific
+#
+# Target architecture (see library "Board Types" documentation).
+ARCH = AVR8
+
+# Input clock frequency.
+#     This will define a symbol, F_USB, in all source code files equal to the
+#     input clock frequency (before any prescaling is performed) in Hz. This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_USB = $(F_CPU)
+
+# Interrupt driven control endpoint task
+OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
+
+
+# Boot Section Size in *bytes*
+#   Teensy halfKay   512
+#   Teensy++ halfKay 1024
+#   Atmel DFU loader 4096
+#   LUFA bootloader  4096
+#   USBaspLoader     2048
+OPT_DEFS += -DBOOTLOADER_SIZE=4096
+
+
+# Build Options
+#   comment out to disable the options.
+#
+#BOOTMAGIC_ENABLE = yes	# Virtual DIP switch configuration
+MOUSEKEY_ENABLE = yes	# Mouse keys
+EXTRAKEY_ENABLE = yes	# Audio control and System control
+CONSOLE_ENABLE = yes	# Console for debug
+COMMAND_ENABLE = yes    # Commands for debug and configuration
+#NKRO_ENABLE = yes	# USB Nkey Rollover
+
+
+# Search Path
+VPATH += $(TARGET_DIR)
+VPATH += $(TOP_DIR)
+
+include $(TOP_DIR)/protocol/lufa.mk
+include $(TOP_DIR)/common.mk
+include $(TOP_DIR)/rules.mk
+
+debug-on: EXTRAFLAGS += -DDEBUG
+debug-on: all
diff --git a/keyboard/hhkb/README.md b/keyboard/hhkb/README.md
index f7e96126..b9e0b534 100644
--- a/keyboard/hhkb/README.md
+++ b/keyboard/hhkb/README.md
@@ -2,128 +2,144 @@ Alternative Controller for HHKB Pro
 ===================================
 I wanted to add some features like vi cursor and mouse keys to my [HHKB][HHKB] but its controller is not programmable and
 firmware source code is not open, of course. This means customizing this keyboard needs to replace original 
-controller with programmable one. For this purpose I used PJRC [Teensy++][Teensy] as alternative controller.
+controller with programmable one. This controller can work with HHKB Professional and Professional 2 model.
+
+See [this thread][AltController] in geekhack.org.
 
 [HHKB]: http://www.pfu.fujitsu.com/hhkeyboard/
+[AltController]: http://geekhack.org/index.php?topic=12047.0
 [Teensy]: http://www.pjrc.com/teensy/
 
 
-My keyboard firmware source tree is here: http://github.com/tmk/tmk_keyboard
-See directory keyboard/hhkb to build firmware for HHKB.
-
-
 ##Features
 * Customizable keymap
 * More keymap layers(more Fn keys)
 * Mouse keys
 * USB NKRO
 
+See README of [tmk_keyboard] for more.
+
+[tmk_keyboard]: http://github.com/tmk/tmk_keyboard
+ 
 ###Pros
+* No risk: Everything is all reversible
 * Without PCB trace cutting, case mod or any destructives
 * Can keep original controller intact
 * Can change all HHKB behaviour as you like
 
 ###Cons
 * Void your warranty
-* Lose USB hub function in case of Pro2
+* Lose USB hub function of Pro2
 
 ##DISCLAIMER
-I'm not a professional of electronics or MCU programming. This may damage your HHKB.
+I'm not a professional of electronics nor MCU programming. This may damage your HHKB.
 And my English writing is poor, I'm not sure I can convey my notions accurately.
 
 
+##Documents
+See [doc/HHKB.txt](doc/HHKB.txt) and files under [doc/](doc/) for internal of HHKB and this controller.
 
 
+##Build Firmware & Program
+You can choose some combination of hardware and USB protocol stack([LUFA], [PJRC]).
+
+### Install Tools
+See [this document](../../doc/build.md).
+
+### TMK Alt Controller Board
+    $ make -f Makefile.tmk
+
+This programs the controller with [dfu-programmer] if the tool is intalled and configured properly.
+
+    $ make -f Makefile.tmk dfu
+
+Push reset button and program with [FLIP]. The tool should be intalled and configured properly.
+
+    $ make -f Makefile.tmk flip
+
+Or you can also program with FLIP GUI.
+
+[dfu-programmer]: http://dfu-programmer.sourceforge.net/
+[FLIP]: http://www.atmel.com/tools/FLIP.aspx
 
 
-##Build Firmware
-You can choose some combination of MCU and USB protocol stack.
+### PJRC Teensy++
+Build with [LUFA] USB stack:
 
-### Teensy++(AVR USB family) with [LUFA]
-0. Edit **matrix.c** to use your pin configuration. See doc/HHKB.txt for detail.
+    $ make -f Makefile.lufa
 
-1. Edit **keymap.c** to use your favoirte keymap.
+or with [PJRC] USB stack:
 
-2. Edit **Makefile** if you want to use other `MCU` than Teensy++ 2.0.
+    $ make -f Makefile.pjrc
 
-3. Build firmware binary file:
-    `$ make -f Makefile.lufa`
+Push reset button and program with [Teensy Loader(command line)]. The tool should be intalled and configured properly.
 
-4. Program MCU with PJRC [Teensy Loader] tool. If you install command line version of the loader just run:
-    `$  make -f Makefile.lufa teensy`
+    $  make -f Makefile.lufa teensy
+    $  make -f Makefile.pjrc teensy
+
+Or you can also program with [Teensy Loader(GUI)].
 
 [LUFA]: http://www.fourwalledcubicle.com/LUFA.php
-[Teensy Loader]: http://www.pjrc.com/teensy/loader.html
+[PJRC]: http://www.pjrc.com/teensy/usb_keyboard.html
+[Teensy Loader(command line)]: http://www.pjrc.com/teensy/loader_cli.html
+[Teensy Loader(GUI)]: http://www.pjrc.com/teensy/loader.html
 
 
 ###AVR Mega with [V-USB]
-Follow below if you want to use AVR with V-USB as .
+Build:
+    $ make -f Makefile.vusb
 
-0. Edit **matrix.c** to use your pin configuration. See doc/HHKB.txt for detail.
+Program [USBaspLoader] on MCU with AVR programmer like [AVRISPmkII] and tool like [avrdude].
 
-1. Edit **keymap.c** to use your favoirte keymap.
+You can programs with [avrdude] once you have programmed [USBaspLoader] on MCU.
+    $  make -f Makefile.vusb program
 
-2. Edit **usbconfig.h** to configure V-USB options. 
-
-3. Edit **Makefile.vusb** to define `MCU` and `F_CPU`.
-
-4. Build firmware binary file:
-    `$ make -f Makefile.vusb`
-
-5. Program MCU with AVR programmer like AVRISPmkII. If you already have [USBaspLoader] on MCU just run:
-    `$  make -f Makefile.vusb program`
-
-[V-USB]: http://www.obdev.at/products/vusb/index.html
-[USBaspLoader]: http://www.obdev.at/products/vusb/usbasploader.html
+[AVRISPmkII]: http://www.atmel.com/tools/AVRISPMKII.aspx
+[avrdude]: http://www.nongnu.org/avrdude/
 
 
-###How to Customize Keymap
-Later...
-See **keymap.c**.
+##How to Customize
+See [tmk_keyboard] documents.
 
 
 ##Hardware
+You have some options for hardware. Development boards with USB AVR family(ATMega32U4, AT90USB1286) like Teensy will work while MegaAVR with V-USB library is also cheapear option for DIY.
 
-###Teensy++ installation
-Angled USB mini B adapter is used to install Teensy++ laterally.
-
-![Image of Teensy install](hhkb/doc/HHKB_img/teensy_install.jpg)
-
-Bread baord wires are used to connect Teensy++.
-
-![Image of Teensy wiring](hhkb/doc/HHKB_img/teensy_wiring.jpg)
-
-![Image of Connector](hhkb/doc/HHKB_img/connector_contact.jpg)
+###1. TMK Alt Controller Board
+TMK designed [Keyboard Controller Board for HHKB Pro2(KiCad project)](https://github.com/tmk/HHKB_controller).
+See [this post](http://geekhack.org/index.php?topic=12047.msg948923#msg948923).
 
 
-###PJRC Teensy++ 2.0 connection
-                            +---------------+
-                            |   Teensy++    |
-                            |               |
-                            |               |        HHKB
-                            |               |        ~~~~
-                            |          PB0-2|------->ROW(6-8)
-                            |          PB3-5|------->COL(9-11)
-                            |            PB6|------->ENABLE(12)
-                            |            PE6|<-------KEY(4)
-                            |            PE7|------->PREV(5)
-                            |               |
-                            |               |
-                            |               |
-                            +---------------+
+###2. PJRC Teensy++ 2.0 connection
+    +---------------+
+    |   Teensy++    |
+    |               |
+    |               |               HHKB pro    HHKB pro2
+    |               |               ~~~~~~~~    ~~~~~~~~~
+    |          PB0-2|------->ROW    (6-8)       (5-7)
+    |          PB3-5|------->COL    (9-11)      (8-10)
+    |            PB6|------->ENABLE (12)        (11)
+    |            PE6|<-------KEY    (4)         (3)
+    |            PE7|------->PREV   (5)         (4)
+    |               |
+    |               |   5V---       (1-3)       (1-2)
+    |               |  GND---       (13-14)     (12-13)
+    +---------------+
 
+- NOTE: PJRC [Teensy](http://www.pjrc.com/teensy/)
+[Teensy Loader]: http://www.pjrc.com/teensy/loader.html
 
-###V-USB circuit
+###3. V-USB connection
                     +---+   +---------------+
-    USB            GND  |   |   ATmega168   |
+    USB            GND  |   |   ATmega328p  |
     ~~~                 C3  |               |
-    5V <-------+--------+---|Vcc,AVCC       |        HHKB
-               R1           |               |        ~~~~
-    D- <----+--+-----R2-----|INT1      PB2-4|------->ROW(6-8)
-    D+ <----|---+----R3-----|INT0      PC0-2|------->COL(9-11)
-            Z1  Z2          |            PC3|------->ENABLE(12)
-    GND<----+---+-----------|GND         PB0|<-------KEY(4)
-                            |            PB1|------->PREV(5)
+    5V <-------+--------+---|Vcc,AVCC       |               HHKB pro    pro2
+               R1           |               |               ~~~~~~~~    ~~~~
+    D- <----+--+-----R2-----|INT1      PB2-4|------->ROW    (6-8)       (5-7)
+    D+ <----|---+----R3-----|INT0      PC0-2|------->COL    (9-11)      (8-10)
+            Z1  Z2          |            PC3|------->ENABLE (12)        (11)
+    GND<----+---+-----------|GND         PB0|<-------KEY    (4)         (3)
+                            |            PB1|------->PREV   (5)         (4)
                             |               |
                 GND+-C2--+--|XTAL1       RXD|------->Debug Console
                          X1 |            TXD|<-------Debug Console
@@ -134,5 +150,11 @@ Bread baord wires are used to connect Teensy++.
     Z1,Z2:  Zener 3.6V
     C1,C2:  22pF
     C3:     0.1uF
-    X1:     Crystal 20MHz(16MHz/12MHz)
-    SW:     Push Switch(Optional for bootloader)
+    X1:     Crystal 12MHz
+    SW:     Push Switch(for bootloader)
+
+- NOTE: See [V-USB] documentation for more detail of hardware and the USB stack.
+- NOTE: [USBaspLoader] is very useful for firmware update.
+
+[V-USB]: http://www.obdev.at/products/vusb/index.html
+[USBaspLoader]: http://www.obdev.at/products/vusb/usbasploader.html
diff --git a/keyboard/hhkb/config.h b/keyboard/hhkb/config.h
index ec51852c..613e66d1 100644
--- a/keyboard/hhkb/config.h
+++ b/keyboard/hhkb/config.h
@@ -54,7 +54,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #endif
 
 /* period of tapping(ms) */
-#define TAPPING_TERM    200
+#define TAPPING_TERM    300
 /* tap count needed for toggling a feature */
 #define TAPPING_TOGGLE  5
 
diff --git a/keyboard/hhkb/doc/HHKB.txt b/keyboard/hhkb/doc/HHKB.txt
index f99a0744..422c452c 100644
--- a/keyboard/hhkb/doc/HHKB.txt
+++ b/keyboard/hhkb/doc/HHKB.txt
@@ -30,25 +30,27 @@ Connector Cable
 Two PCBs are connected by 15 lines(13 in case of Pro2).
 Vcc and GND use 3(2) lines each, other 9 lines are for keyboard signaling.
 
-    Keyswitch PCB connector                                 Teensy++ pins
-    -------------------------------------------------------------------------------
-     1  Vcc(5V)   Not exist on Pro2                         5V
-     2  Vcc(5V)                                             5V
-     3  Vcc(5V)                                             5V
-     4  TP1684    KEY: Low(0) when key pressed              PE6 input(with pullup)
-     5  TP1684    KEY_PREV: assert previous key state???    PE7 output
-     6  HC4051    A(bit0) select 8 rows(0 to 7)             PB0 output
-     7  HC4051    B(bit1)                                   PB1 output
-     8  HC4051    C(bit2)                                   PB2 output
-     9  LS145     A(bit0) select 8 columns(0 to 7)          PB3 output
-    10  LS145     B(bit1)                                   PB4 output
-    11  LS145     C(bit2)                                   PB5 output
-    12  LS145     D(enable) Low(0) enable selected column   PB6 output
-    13  GND                                                 GND
-    14  GND                                                 GND
-    15  GND       Not exist on Pro2                         GND
+    Keyswitch connector
+    pro  pro2           Description                               Teensy++ pins
+    --------------------------------------------------------------------------------------------
+     1       Vcc(5V)    Not exist on Pro2                         5V
+     2   1   Vcc(5V)                                              5V
+     3   2   Vcc(5V)                                              5V
+     4   3   TP1684     KEY: Low(0) when key pressed              PE6 input(with pullup)
+     5   4   TP1684     KEY_PREV: make threshold                  PE7 output
+     6   5   HC4051     A(bit0)\                                  PB0 output
+     7   6   HC4051     B(bit1) > select row(0 to 7)              PB1 output
+     8   7   HC4051     C(bit2)/                                  PB2 output
+     9   8   LS145      A(bit0)\                                  PB3 output
+    10   9   LS145      B(bit1) > select column(0 to 7)           PB4 output
+    11  10   LS145      C(bit2)/                                  PB5 output
+    12  11   LS145      D(enable) Low(0) enables selected column  PB6 output
+    13  12   GND                                                  GND
+    14  13   GND                                                  GND
+    15       GND        Not exist on Pro2                         GND
 
     NOTE: guessing pin5(KEY_PREV) may work for hysteresis of capacitive sensing.
+    NOTE: 1KOhm didn't work as pullup resistor on KEY. AVR internal pullup or 10KOhm resistor was OK.
 
     (HHKB_connector.jpg)
 
diff --git a/keyboard/hhkb/doc/Power.txt b/keyboard/hhkb/doc/Power.txt
new file mode 100644
index 00000000..1287053c
--- /dev/null
+++ b/keyboard/hhkb/doc/Power.txt
@@ -0,0 +1,48 @@
+HHKB Power consumption
+----------------------
+
+**Power consumption
+    board   clock/prescaler     keyswitch   power ctrl      current
+    --------------------------------------------------------------------------
+    tmk     16MHz               no          no              26.4mA
+    tmk     16MHz               pro1        no              45.1mA
+    tmk     16MHz/2             no          no              18.1mA
+    tmk     16MHz/2             pro1        no              37.3mA
+    tmk     8MHz                no          no              18.9mA
+    tmk     8MHz                pro2        no(w/o FET)     32.1mA
+    tmk     8MHz                pro2        no(w FET)       32.1mA withou POWER_ON/FF
+    tmk     8MHz                pro2        no(w FET)       32.6mA with POWR_ON/OFF
+    tmk     8MHz                pro2        15ms(w FET)     21.3mA with POWR_ON/OFF, enumerated but error -32
+    tmk     8MHz                pro2        60ms(w FET)     13.3mA with POWR_ON/OFF, not enumerated
+
+    gh60    16MHz                                           25.8mA
+    gh60    16MHz               USB suspend w LED breathing 17.6-29.1mA
+    gh60    16MHz               USB suspend w/o LED         0.2mA(0.231-0.276mA)
+    Poker                                                    5.6mA
+    Poker                       USB suspend                  0.3mA(0.301mA)
+    gh60    16MHz               stock firmware by komar     26.8mA
+
+
+    HHKB pro2 Over All                                     139.4mA
+    HHKB pro2 Controller                                   115.1mA
+    HHKB pro1 Controller                                    25.9mA
+
+
+keyswitch power consumption:
+pro1: 45.1-26.4=18.7mA
+      37.3-18.1=19.2mA
+pro2: 32.1-18.9=13.2mA
+
+
+
+
+
+**Low Freq Crystal or Prescaler?
+No advantage of Low Freq Crystal against Prescaled.
+
+Clock routing
+X'tal --+---->Prescaler-------> System Clock
+        |
+        +---------------------> USB PLL
+
+Design Decision: Install 16MHz crystal on board with using clock rescaler.
diff --git a/keyboard/hhkb/led.c b/keyboard/hhkb/led.c
index 669b6107..8a08fe27 100644
--- a/keyboard/hhkb/led.c
+++ b/keyboard/hhkb/led.c
@@ -15,6 +15,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <avr/io.h>
 #include "stdint.h"
 #include "led.h"
 
@@ -22,5 +23,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 /* HHKB has no LEDs */
 void led_set(uint8_t usb_led)
 {
+    if (usb_led & (1<<USB_LED_CAPS_LOCK)) {
+        DDRD |= (1<<6);
+        PORTD |= (1<<6);
+    } else {
+        DDRD |= (1<<6);
+        PORTD &= ~(1<<6);
+    }
 }
-
diff --git a/keyboard/hhkb/matrix.c b/keyboard/hhkb/matrix.c
index 3d4b1f6c..d0731ef1 100644
--- a/keyboard/hhkb/matrix.c
+++ b/keyboard/hhkb/matrix.c
@@ -63,7 +63,7 @@ static matrix_row_t _matrix1[MATRIX_ROWS];
     PORTE |= (1<<6);                    \
 } while (0)
 #define KEY_SELECT(ROW, COL)    (PORTB = (PORTB & 0xC0) |       \
-                                         (((COL) & 0x07)<<3) |    \
+                                         (((COL) & 0x07)<<3) |  \
                                          ((ROW) & 0x07))
 #define KEY_ENABLE()            (PORTB &= ~(1<<6))
 #define KEY_UNABLE()            (PORTB |=  (1<<6))
@@ -73,6 +73,50 @@ static matrix_row_t _matrix1[MATRIX_ROWS];
 #define KEY_POWER_ON()
 #define KEY_POWER_OFF()
 
+#elif defined(__AVR_ATmega32U4__)
+// Ports for my designed Alt Controller PCB
+// row:     PB0-2
+// col:     PB3-5,6
+// key:     PD7(pull-uped)
+// prev:    PB7
+// power:   PD4(L:off/H:on)
+#define KEY_INIT()              do {    \
+    DDRB  = 0xFF;                       \
+    PORTB = 0x00;                       \
+    DDRD  &= ~0x80;                     \
+    PORTD |= 0x80;                      \
+    /* keyswitch board power on */      \
+    DDRD  |=  (1<<4);                   \
+    PORTD |=  (1<<4);                   \
+    KEY_UNABLE();                       \
+    KEY_PREV_OFF();                     \
+} while (0)
+#define KEY_SELECT(ROW, COL)    (PORTB = (PORTB & 0xC0) |       \
+                                         (((COL) & 0x07)<<3) |  \
+                                         ((ROW) & 0x07))
+#define KEY_ENABLE()            (PORTB &= ~(1<<6))
+#define KEY_UNABLE()            (PORTB |=  (1<<6))
+#define KEY_STATE()             (PIND & (1<<7))
+#define KEY_PREV_ON()           (PORTB |=  (1<<7))
+#define KEY_PREV_OFF()          (PORTB &= ~(1<<7))
+#define KEY_POWER_ON()
+#define KEY_POWER_OFF()
+/*
+#define KEY_POWER_ON()          do {    \
+    KEY_INIT();                         \
+    PORTD |=  (1<<4);                   \
+    _delay_ms(1);                       \
+} while (0)
+#define KEY_POWER_OFF()         do {    \
+    PORTD &= ~(1<<4);                   \
+    DDRB  &= ~0xFF;                     \
+    PORTB &= ~0xFF;                     \
+    DDRB  &= ~0x80;                     \
+    PORTB &= ~0x80;                     \
+} while (0)
+*/
+
+
 #elif defined(__AVR_ATmega328P__)
 // Ports for V-USB
 // key:     PB0(pull-uped)
@@ -130,7 +174,6 @@ uint8_t matrix_cols(void)
 void matrix_init(void)
 {
 #ifdef DEBUG
-    print_enable = true;
     debug_enable = true;
     debug_keyboard = true;
 #endif
@@ -170,9 +213,21 @@ uint8_t matrix_scan(void)
             uint8_t last = TIMER_RAW;
 
             KEY_ENABLE();
+
             // Wait for KEY_STATE outputs its value.
             // 1us was ok on one HHKB, but not worked on another.
-            _delay_us(10);
+            // no   wait doesn't work on Teensy++ with pro(1us works)
+            // no   wait does    work on tmk PCB(8MHz) with pro2
+            // 1us  wait does    work on both of above
+            // 1us  wait doesn't work on tmk(16MHz)
+            // 5us  wait does    work on tmk(16MHz)
+            // 5us  wait does    work on tmk(16MHz/2)
+            // 5us  wait does    work on tmk(8MHz)
+            // 10us wait does    work on Teensy++ with pro
+            // 10us wait does    work on 328p+iwrap with pro
+            // 10us wait doesn't work on tmk PCB(8MHz) with pro2(very lagged scan)
+            _delay_us(5);
+
             if (KEY_STATE()) {
                 matrix[row] &= ~(1<<col);
             } else {