diff options
Diffstat (limited to 'hhkb/doc')
| -rw-r--r-- | hhkb/doc/HHKB.txt | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/hhkb/doc/HHKB.txt b/hhkb/doc/HHKB.txt index 3ca272c80..e9f41adab 100644 --- a/hhkb/doc/HHKB.txt +++ b/hhkb/doc/HHKB.txt @@ -84,7 +84,7 @@ Two PCBs are connected by 15 lines. Vcc and GND use 3 lines each, other 9 lines 2 Vcc(5V) 3 Vcc(5V) 4 TP1684 KEY: Low(0) when key pressed PE6 input(with pullup) - 5 TP1684 unknown:how to use PE7 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 @@ -148,9 +148,11 @@ Signals charts: (HHKB_chart1.jpg) - Space bar locate at ROW:3 COL:7. Key are selected by HC4051(C,B,A) and LS145(C,B,A). + 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 unknown. Key state can be read without using this signal. + + 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) @@ -162,7 +164,13 @@ Matrix scan pseudo code: for (col: 0-7) { SELECT_COL(col); // set LS145(A,B,C) - _delay_us(50); + _delay_us(40); + + if (prev_key_state(row, col)) { + KEY_PREV_ON; + } + + _delay_us(7); ENALBLE_COL(); // set LS145(D) to low @@ -174,6 +182,7 @@ Matrix scan pseudo code: // not pressed } + KEY_PREV_OFF; UNALBLE_COL(); // set LS145(D) to high _delay_us(150); |