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Diffstat (limited to 'keyboard/hhkb/doc/HHKB.txt')
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diff --git a/keyboard/hhkb/doc/HHKB.txt b/keyboard/hhkb/doc/HHKB.txt new file mode 100644 index 0000000000..ace931de38 --- /dev/null +++ b/keyboard/hhkb/doc/HHKB.txt @@ -0,0 +1,199 @@ +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: + 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: + 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 + TP1683/4 Capacitive Sensing controller: no datasheet available. + + (HHKB_keyswitch.jpg) + + Topre original chip? + (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 + + (HHKB_connector.jpg) + + +Keyswitch matrix +---------------- +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_ + + +Matrix diagram: + +-------------------------+-+-+-+-+-+-+-+ Vcc + |bias control? - - - - - - - - --- + | 3.9K*8 R R R R R R R R | + +--------^+ +--------+ - - - - - - - - | + | 2| | HC4051 <0-------|-|-|-|-|-|-|-|--|R|-+ + | |capa. | <1-------|-|-|-|-|-|-|-|--|R|-+ + | TP1684 |sense | <2-------|-|-|-|-|-|-|-|--|R|-+ + | 11<------| <3-------|-|-|-|-|-|-|-|--|R|-+ + | | | <4-------|-|-|-|-|-|-|-|--|R|-+ + | | | <5-------|-|-|-|-|-|-|-|--|R|-+ + | <-+ | <6-------|-|-|-|-|-|-|-|--|R|-+ + | 1 4 | | | <7-------|-|-|-|-|-|-|-|--|R|-+ + +---V---^-+ | +-^-^-^--+ 0 1 2 3 4 5 6 7 33K*8 + KEY PREV | 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. A key is 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 not clear. Controller seemed to output previous key state on this line. + However 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(40); + + if (prev_key_state(row, col)) { + KEY_PREV_ON; + } + + _delay_us(7); + + ENALBLE_COL(); // set LS145(D) to low + + _delay_us(10); + + if (KEY == 0) { // read TP1684(KEY) + // key pressed + } else { + // not pressed + } + + KEY_PREV_OFF; + UNALBLE_COL(); // set LS145(D) to high + + _delay_us(150); + } + } + + +Keymap layers +------------- +Followings are added layers with additional Fn keys. + +see keymap.c + +EOF |