--- /dev/null
+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.
+
+This is just a proof of concept for replacing controller of HHKB, not a complete firmware.
+
+My prototype firmware source tree is here:
+ branch: hhkb(http://github.com/tmk/tmk_keyboard/tree/hhkb)
+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 cuting, 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 cables used for connect Teensy++.
+(teensy_wiring.jpg)
+(connector_contact.jpg)
+
+
+HHKB internal
+-------------
+HHKB pro has two PCBs and some chips.
+
+Controller PCB:
+ M38K07M4 Renesas MCU with USB function
+ http://documentation.renesas.com/eng/products/mpumcu/rej03b0192_38k0ds.pdf
+ (HHKB_controller.jpg)
+
+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.
+ http://www.alldatasheet.com/datasheet-pdf/pdf/27373/TI/SN74LS145D.html
+ BU9831 Non-volatile electronic potentiometer: for calibration?
+ http://www.alldatasheet.com/datasheet-pdf/pdf/36387/ROHM/BU9831.html
+ TP1684 Capacitive Sensing controller: no datasheet available.
+ (HHKB_keyswitch.jpg)
+ Topre original chip?
+ (HHKB_TP1684.jpg)
+
+
+Two PCBs are connected by 15 lines. Vcc/GND uses 3 lines each, 9lines 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 w/o pullup
+ 5 TP1684 unknown:how to use PE7 input w/o pullup
+ 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
+ (HHKB_connector.jpg)
+
+
+Keyswitch matrix
+----------------
+60 keyswitches in 8*8 matrix. ghost free. 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_
+
+
+Matrix diagram:
+ +-------------------------+-+-+-+-+-+-+-+ Vcc
+ |bias control? - - - - - - - - ---
+ | 3.9K*8 R R R R R R R R |
+ +--------^+ +--------+ - - - - - - - - |
+ | TP 1684 | | HC4051 <0-------|-|-|-|-|-|-|-|--|R|-+
+ | |capa. | <1-------|-|-|-|-|-|-|-|--|R|-+
+ | |sense | <2-------|-|-|-|-|-|-|-|--|R|-+
+ | <------| <3-------|-|-|-|-|-|-|-|--|R|-+
+ | | | <4-------|-|-|-|-|-|-|-|--|R|-+
+ | | | <5-------|-|-|-|-|-|-|-|--|R|-+
+ | |calib.| <6-------|-|-|-|-|-|-|-|--|R|-+
+ | <-+? | <7-------|-|-|-|-|-|-|-|--|R|-+
+ +---V-----+ | +-^-^-^--+ 0 1 2 3 4 5 6 7 33K*8
+ KEY ??? | A B C +-----------------+
+ | | +-^----+ | | | | LS145 |
+ Vcc | | |BU9831| | | | +-^--^--^--^------+
+ --- | | +------+ | | | A B C D +------+
+ | | | | | | | | | | | |
+ 1-3 4 5 6 7 8 9 10 11 12 13-15 |
+ +--------------------------------------------------+ |
+ | connector | ---
+ +--------------------------------------------------+ GND
+ to controller
+
+
+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_chart1.jpg)
+
+ Space bar locate at ROW:3 COL:7. Key are selected by HC4051(C,B,A) and LS145(C,B,A).
+ Key state can be read on TP1684(4/KEY) while asserting low on LS145(D).
+ Usage of TP1684(5) is unknown. Key state can be read without using this signal.
+ (HHKB_chart2.jpg)
+
+
+Matrix scan pseudo code:
+ for (row: 0-7) {
+ SELECT_ROW(row); // set HC4051(A,B,C)
+
+ for (col: 0-7) {
+ SELECT_COL(col); // set LS145(A,B,C)
+
+ _delay_us(50);
+
+ ENALBLE_COL(); // set LS145(D) to low
+
+ _delay_us(10);
+
+ if (KEY == 0) { // read TP1684(KEY)
+ // key pressed
+ } else {
+ // not pressed
+ }
+ }
+ }
+
+
+Keymap layers
+-------------
+Followings are added layers with additional Fn keys. They are not final decision.
+
+Layer0(Default Layer):
+ ,-----------------------------------------------------------.
+ |Esc| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =| \| `|
+ |-----------------------------------------------------------|
+ |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]|Backs|
+ |-----------------------------------------------------------|
+ |Contro| A| S| D| F| G| H| J| K| L| ;| '|Return |
+ |-----------------------------------------------------------|
+ |Shift | Z| X| C| V| B| N| M| ,| .| /|Fn2 |Fn1|
+ `-----------------------------------------------------------'
+ |Gui|Alt |Space |Fn3 |Gui|
+ `-------------------------------------------'
+
+Layer1(Fn1) HHKB mode:
+ ,-----------------------------------------------------------.
+ |Pow| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Ins|Del|
+ |-----------------------------------------------------------|
+ |Caps | | | | | | | |Psc|Slk|Pus|Up | |Backs|
+ |-----------------------------------------------------------|
+ |Contro|VoD|VoU|Mut| | | *| /|Hom|PgU|Lef|Rig|Enter |
+ |-----------------------------------------------------------|
+ |Shift | | | | | | +| -|End|PgD|Dow|Shift |xxx|
+ `-----------------------------------------------------------'
+ |Gui |Alt |Space |Alt |Gui|
+ `--------------------------------------------'
+
+Layer2(Fn2) mouse mode:
+ ,-----------------------------------------------------------.
+ |Esc| | | | | | | | | | | | | | |
+ |-----------------------------------------------------------|
+ |Tab | | | | | | | | | | | | |Backs|
+ |-----------------------------------------------------------|
+ |Contro| | | | | | | |MwL|MwD|MwU|MwR|Return |
+ |-----------------------------------------------------------|
+ |Shift | | | | | | |McL|McD|McU|McR|xxxxxx| |
+ `-----------------------------------------------------------'
+ |Gui |Alt |Mb1 |Mb1 |Mb2|
+ `--------------------------------------------'
+
+Layer3(Fn3) vi mode:
+ ,-----------------------------------------------------------.
+ |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12| | |
+ |-----------------------------------------------------------|
+ |Tab | | | | | |Hom|PgD|PgUlEnd| |MwD|MwU|Backs|
+ |-----------------------------------------------------------|
+ |Contro| | | | | |Lef|Dow|Up |Rig| | |Return |
+ |-----------------------------------------------------------|
+ |Shift | | | | | | |McL|McD|McU|McR|Mb1 | |
+ `-----------------------------------------------------------'
+ |Gui|Alt |Mb1 |xxxxx|Mb2|
+ `-------------------------------------------'
+ Mc: Mouse Cursor / Mb: Mouse Button / Mw: Mouse Wheel
+
+EOF
projects / tmk_firmware.git / commitdiff
