HHKB/HHKB.txt

   1 Alternative Controller for HHKB pro
   2 ===================================
   3 I want to add vi cursor and mouse keys to HHKB. Original HHKB controller is not programmable and
   4 firmware source code is not open. So, customizing HHKB needs to replace original controller with programmable one.
   5 I used Teensy++ as alternative controller. Though a Teensy has enough ports to drive HHKB,
   6 Teensy++ has clean pinout and it makes programing and wiring easier.
   7
   8 This is just a proof of concept for replacing controller of HHKB, not a complete firmware.
   9
  10 My prototype firmware source tree is here:
  11     branch: hhkb(http://github.com/tmk/tmk_keyboard/tree/hhkb)
  12 This firmware is a port of my previous project:
  13     HHKB style Mod(http://geekhack.org/showwiki.php?title=Island:11930)
  14 PJRC(Teensy++/Teensy)
  15     http://www.pjrc.com/teensy/
  16
  17
  18 Pros:
  19     * without pattern cuting, case mod  and soldering
  20     * can keep original controller intact
  21     * can change HHKB behaviour as you like(by C programming)
  22
  23 Cons:
  24     * void your warranty
  25     * unavailability of Teensy++/Teensy(because of PS3 cracking boom?)
  26
  27 Features:
  28     * customized keymap
  29     * more keymap layers
  30     * mouse keys for minimum mouse operation(never comfortable for normal use)
  31     * and more...(in the future)
  32
  33 Any suggestions or ideas are welcome.
  34
  35
  36 NOTE:
  37     My HHKB is just "Professional". This means followings may not be applied to "Professional2".
  38 DISCLAIMER:
  39     I'm not a professional for electronics and MCU programming. This may damage your HHKB.
  40     And my English writing is poor, I'm not sure I can convey my notions accurately.
  41
  42
  43 Teensy++ installation
  44 ---------------------
  45 Angled USB mini B adapter is used to install Teensy++ laterally.
  46 (teensy_install.jpg)
  47
  48 Bread baord cables used for connect Teensy++.
  49 (teensy_wiring.jpg)
  50 (connector_contact.jpg)
  51
  52
  53 HHKB internal
  54 -------------
  55 HHKB pro has two PCBs and some chips.
  56
  57 Controller PCB:
  58     M38K07M4    Renesas MCU with USB function
  59                 http://documentation.renesas.com/eng/products/mpumcu/rej03b0192_38k0ds.pdf
  60     (HHKB_controller.jpg)
  61
  62 Keyswitch PCB:
  63     HC4051      Analog Multiplexer: select a row line.
  64                 http://www.alldatasheet.com/datasheet-pdf/pdf/203989/KODENSHI/KK74HC4051A.html
  65     LS145       BCD Decoder: select a column line.
  66                 http://www.alldatasheet.com/datasheet-pdf/pdf/27373/TI/SN74LS145D.html
  67     BU9831      Non-volatile electronic potentiometer: for calibration?
  68                 http://www.alldatasheet.com/datasheet-pdf/pdf/36387/ROHM/BU9831.html
  69     TP1684      Capacitive Sensing controller: no datasheet available.
  70     (HHKB_keyswitch.jpg)
  71     Topre original chip?
  72     (HHKB_TP1684.jpg)
  73
  74
  75 Two PCBs are connected by 15 lines. Vcc/GND uses 3 lines each, 9lines for keyboard signaling.
  76
  77     Keyswitch PCB connector                                 Teensy++ pins
  78     -------------------------------------------------------------------------------
  79      1  Vcc(5V)                                             5V
  80      2  Vcc(5V)
  81      3  Vcc(5V)
  82      4  TP1684    KEY: Low(0) when key pressed              PE6 input w/o pullup
  83      5  TP1684    unknown:how to use                        PE7 input w/o pullup
  84      6  HC4051    A(bit0) select 8 rows(0 to 7)             PB0 output
  85      7  HC4051    B(bit1)                                   PB1 output
  86      8  HC4051    C(bit2)                                   PB2 output
  87      9  LS145     A(bit0) select 8 columns(0 to 7)          PB3 output
  88     10  LS145     B(bit1)                                   PB4 output
  89     11  LS145     C(bit2)                                   PB5 output
  90     12  LS145     D(enable) Low(0) enable selected column   PB6 output
  91     13  GND
  92     14  GND
  93     15  GND                                                 GND
  94     (HHKB_connector.jpg)
  95
  96
  97 Keyswitch matrix
  98 ----------------
  99 60 keyswitches in 8*8 matrix. ghost free. bounce free.
 100
 101   COL 0     1       2       3       4       5       6       7
 102 ROW ---------------------------------------------------------------
 103   0|  2     q       w       s       a       z       x       c
 104   1|  3     4       r       e       d       f       v       b
 105   2|  5     6       y       t       g       h       n       _NONE_
 106   3|  1     Esc     Tab     Control LShift  LAlt    LMeta   Space
 107   4|  7     8       u       i       k       j       m       _NONE_
 108   5|  \     `       Delete  Return  Fn      RShift  RAlt    RMeta
 109   6|  9     0       o       p       ;       l       ,       _NONE_
 110   7|  -     +       ]       [       '       /       .       _NONE_
 111
 112
 113 Matrix diagram:
 114              +-------------------------+-+-+-+-+-+-+-+     Vcc
 115              |bias control?            - - - - - - - -     ---
 116              |                  3.9K*8 R R R R R R R R      |
 117     +--------^+      +--------+        - - - - - - - -      |
 118     | TP 1684 |      | HC4051 <0-------|-|-|-|-|-|-|-|--|R|-+
 119     |         |capa. |        <1-------|-|-|-|-|-|-|-|--|R|-+
 120     |         |sense |        <2-------|-|-|-|-|-|-|-|--|R|-+
 121     |         <------|        <3-------|-|-|-|-|-|-|-|--|R|-+
 122     |         |      |        <4-------|-|-|-|-|-|-|-|--|R|-+
 123     |         |      |        <5-------|-|-|-|-|-|-|-|--|R|-+
 124     |         |calib.|        <6-------|-|-|-|-|-|-|-|--|R|-+
 125     |         <-+?   |        <7-------|-|-|-|-|-|-|-|--|R|-+
 126     +---V-----+ |    +-^-^-^--+        0 1 2 3 4 5 6 7  33K*8
 127        KEY ???  |      A B C         +-----------------+
 128         |   | +-^----+ | | |         |      LS145      |
 129     Vcc |   | |BU9831| | | |         +-^--^--^--^------+
 130     --- |   | +------+ | | |           A  B  C  D   +------+
 131      |  |   |          | | |           |  |  |  |   |      |
 132     1-3 4   5          6 7 8           9 10 11 12 13-15    |
 133     +--------------------------------------------------+   |
 134     |                connector                         |  ---
 135     +--------------------------------------------------+  GND
 136                     to controller
 137
 138
 139 Signals charts:
 140     While pressing space bar, watched HHKB original controller signals by logic analyzer.
 141     Row and column is looping between 0-7 each for selecting a key.
 142     A key is scaned every about 15ms, so scan rate is 66Hz.
 143     (HHKB_chart1.jpg)
 144
 145     Space bar locate at ROW:3 COL:7. Key are selected by HC4051(C,B,A) and LS145(C,B,A).
 146     Key state can be read on TP1684(4/KEY) while asserting low on LS145(D).
 147     Usage of TP1684(5) is unknown. Key state can be read without using this signal.
 148     (HHKB_chart2.jpg)
 149
 150
 151 Matrix scan pseudo code:
 152     for (row: 0-7) {
 153         SELECT_ROW(row);        // set HC4051(A,B,C)
 154
 155         for (col: 0-7) {
 156             SELECT_COL(col);    // set LS145(A,B,C)
 157
 158             _delay_us(50);
 159
 160             ENALBLE_COL();      // set LS145(D) to low
 161
 162             _delay_us(10);
 163
 164             if (KEY == 0) {     // read TP1684(KEY)
 165                 // key pressed
 166             } else {
 167                 // not pressed
 168             }
 169         }
 170     }
 171
 172
 173 Keymap layers
 174 -------------
 175 Followings are added layers with additional Fn keys. They are not final decision.
 176
 177 Layer0(Default Layer):
 178     ,-----------------------------------------------------------.
 179     |Esc|  1|  2|  3|  4|  5|  6|  7|  8|  9|  0|  -|  =|  \|  `|
 180     |-----------------------------------------------------------|
 181     |Tab  |  Q|  W|  E|  R|  T|  Y|  U|  I|  O|  P|  [|  ]|Backs|
 182     |-----------------------------------------------------------|
 183     |Contro|  A|  S|  D|  F|  G|  H|  J|  K|  L|  ;|  '|Return  |
 184     |-----------------------------------------------------------|
 185     |Shift   |  Z|  X|  C|  V|  B|  N|  M|  ,|  .|  /|Fn2   |Fn1|
 186     `-----------------------------------------------------------'
 187           |Gui|Alt  |Space                  |Fn3  |Gui|
 188           `-------------------------------------------'
 189
 190 Layer1(Fn1) HHKB mode:
 191     ,-----------------------------------------------------------.
 192     |Pow| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Ins|Del|
 193     |-----------------------------------------------------------|
 194     |Caps |   |   |   |   |   |   |   |Psc|Slk|Pus|Up |   |Backs|
 195     |-----------------------------------------------------------|
 196     |Contro|VoD|VoU|Mut|   |   |  *|  /|Hom|PgU|Lef|Rig|Enter   |
 197     |-----------------------------------------------------------|
 198     |Shift   |   |   |   |   |   |  +|  -|End|PgD|Dow|Shift |xxx|
 199     `-----------------------------------------------------------'
 200          |Gui |Alt  |Space                  |Alt  |Gui|
 201          `--------------------------------------------'
 202
 203 Layer2(Fn2) mouse mode:
 204     ,-----------------------------------------------------------.
 205     |Esc|   |   |   |   |   |   |   |   |   |   |   |   |   |   |
 206     |-----------------------------------------------------------|
 207     |Tab  |   |   |   |   |   |   |   |   |   |   |   |   |Backs|
 208     |-----------------------------------------------------------|
 209     |Contro|   |   |   |   |   |   |   |MwL|MwD|MwU|MwR|Return  |
 210     |-----------------------------------------------------------|
 211     |Shift   |   |   |   |   |   |   |McL|McD|McU|McR|xxxxxx|   |
 212     `-----------------------------------------------------------'
 213          |Gui |Alt  |Mb1                    |Mb1  |Mb2|
 214          `--------------------------------------------'
 215
 216 Layer3(Fn3) vi mode:
 217     ,-----------------------------------------------------------.
 218     |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|   |   |
 219     |-----------------------------------------------------------|
 220     |Tab  |   |   |   |   |   |Hom|PgD|PgUlEnd|   |MwD|MwU|Backs|
 221     |-----------------------------------------------------------|
 222     |Contro|   |   |   |   |   |Lef|Dow|Up |Rig|   |   |Return  |
 223     |-----------------------------------------------------------|
 224     |Shift   |   |   |   |   |   |   |McL|McD|McU|McR|Mb1   |   |
 225     `-----------------------------------------------------------'
 226           |Gui|Alt  |Mb1                    |xxxxx|Mb2|
 227           `-------------------------------------------'
 228     Mc: Mouse Cursor / Mb: Mouse Button / Mw: Mouse Wheel
 229
 230 EOF