-Alternative Controller for HHKB pro
-===================================
-I want to add vi cursor and mouse keys to HHKB. Original HHKB controller is not programmable and
-firmware source code is not open. So, customizing HHKB needs to replace original controller with programmable one.
-I used Teensy++ as alternative controller. Though a Teensy has enough ports to drive HHKB,
-Teensy++ has clean pinout and it makes programing and wiring easier.
+Internal of HHKB pro
+=====================
+HHKB pro has MCU and some chips on separate two PCBs.
-This is just a proof of concept for replacing controller of HHKB, not a complete firmware.
-
-My prototype firmware source tree is here:
- github(http://github.com/tmk/tmk_keyboard)
-This firmware is a port of my previous project:
- HHKB style Mod(http://geekhack.org/showwiki.php?title=Island:11930)
-PJRC:
- Teensy++/Teensy(http://www.pjrc.com/teensy/)
-
-
-Pros:
- * without pattern cutting, case mod and soldering
- * can keep original controller intact
- * can change HHKB behaviour as you like(by C programming)
-
-Cons:
- * void your warranty
- * unavailability of Teensy++/Teensy(because of PS3 cracking boom?)
-
-Features:
- * customized keymap
- * more keymap layers
- * mouse keys for minimum mouse operation(never comfortable for normal use)
- * and more...(in the future)
-
-Any suggestions or ideas are welcome.
-
-
-NOTE:
- My HHKB is just "Professional". This means followings may not be applied to "Professional2".
-
-DISCLAIMER:
- I'm not a professional for electronics and MCU programming. This may damage your HHKB.
- And my English writing is poor, I'm not sure I can convey my notions accurately.
-
-
-Teensy++ installation
----------------------
-Angled USB mini B adapter is used to install Teensy++ laterally.
-(teensy_install.jpg)
-
-Bread baord wires are used to connect Teensy++.
-(teensy_wiring.jpg)
-(connector_contact.jpg)
-
-
-HHKB internal
--------------
-HHKB pro has some chips on separate two PCBs.
-
-Controller PCB:
+Controller PCB
+--------------
M38K07M4 Renesas MCU with USB function
http://documentation.renesas.com/eng/products/mpumcu/rej03b0192_38k0ds.pdf
(HHKB_controller.jpg)
-Keyswitch PCB:
+Keyswitch PCB
+-------------
HC4051 Analog Multiplexer: select a row line.
http://www.alldatasheet.com/datasheet-pdf/pdf/203989/KODENSHI/KK74HC4051A.html
LS145 BCD Decoder: select a column line.
(HHKB_TP1684.jpg)
-Two PCBs are connected by 15 lines. Vcc and GND use 3 lines each, other 9 lines are for keyboard signaling.
-
- Keyswitch PCB connector Teensy++ pins
- -------------------------------------------------------------------------------
- 1 Vcc(5V) 5V
- 2 Vcc(5V)
- 3 Vcc(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
- 14 GND
- 15 GND GND
+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 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)
----------------
60 keyswitches in 8*8 matrix. It is ghost-free and bounce-free.
- COL 0 1 2 3 4 5 6 7
-ROW ---------------------------------------------------------------
- 0| 2 q w s a z x c
- 1| 3 4 r e d f v b
- 2| 5 6 y t g h n _NONE_
- 3| 1 Esc Tab Control LShift LAlt LMeta Space
- 4| 7 8 u i k j m _NONE_
- 5| \ ` Delete Return Fn RShift RAlt RMeta
- 6| 9 0 o p ; l , _NONE_
- 7| - + ] [ ' / . _NONE_
+ COL 0 1 2 3 4 5 6 7
+ ROW ---------------------------------------------------------------
+ 0| 2 q w s a z x c
+ 1| 3 4 r e d f v b
+ 2| 5 6 y t g h n _NONE_
+ 3| 1 Esc Tab Control LShift LAlt LMeta Space
+ 4| 7 8 u i k j m _NONE_
+ 5| \ ` Delete Return Fn RShift RAlt RMeta
+ 6| 9 0 o p ; l , _NONE_
+ 7| - + ] [ ' / . _NONE_
Matrix diagram:
+
+-------------------------+-+-+-+-+-+-+-+ Vcc
|bias control? - - - - - - - - ---
| 3.9K*8 R R R R R R R R |
to controller
-Signals charts:
+Signals charts
+--------------
While pressing space bar, watched HHKB original controller signals by logic analyzer.
Row and column is looping between 0-7 each for selecting a key.
A key is scaned every about 15ms, so scan rate is 66Hz.
(HHKB_chart2.jpg)
-Matrix scan pseudo code:
+Matrix scan pseudo code
+-----------------------
for (row: 0-7) {
SELECT_ROW(row); // set HC4051(A,B,C)
}
-Keymap layers
--------------
-Followings are added layers with additional Fn keys.
-
-see keymap.c
EOF
projects / max / tmk_keyboard.git / blobdiff