@@ 162,7 162,7 @@ Matrix diagram:
Signals charts
--------------
- While pressing space bar, watched HHKB original controller signals by logic analyzer.
+ While pressing space bar, watched HHKB Pro 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.
@@ 171,71 171,32 @@ Signals charts
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)
-5us after setting colA-C
-colA _~~~~~~~~~~~~~~~~~~
-prev _~~~~_____ 20us if previous key state is low
-colD ~~~__~~~~~ 10us column enabled
-key ~~~____~~~ 22us hold state of the key
-
-prev ____~~~~__________ 20us(JP)/17us(Pro2)
-key ~~~~~~_____~~~~~~~ 22us
-colD ~~~~~~__~~~~~~~~~~ 10us(LS175)
-
-colC ____~~~~____~~~~ 550/410us(JP)
-colB __~~__~~__~~__~~ 200/210us(JP)
-colA _~_~_~_~_~_~_~_~ 100/110us(JP) 200/210us(Pro2)
- 0123456701234567 selected column
-
-rowC ____~~~~____~~~~ 3.8/3.8ms(JP) S2 of HC4051
-rowB __~~__~~__~~__~~ 1.9/1.9ms(JP) S1 of HC4051
-rowA _~_~_~_~_~_~_~_~ 1.0/1.0ms(JP) S0 of HC4051
- 0123456701234567 selected row(Pro/Pro2)
- 0123456789ABCDEF selected row(JP)
-rowEn0 ________~~~~~~~~ 7.7/7.7ms ~Enable of Z2 HC4051(JP only)
-rowEn1 ~~~~~~~~________ 7.7/7.7ms ~Enable of Z3 HC4051(JP only)
-
-NOTE: JP scans twice fast as Pro2 does. So Pro2 scan 8x8 matrix in 15.4ms while JP can 16x8 in that time.
-
-
-
-
-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
+ Signal of JP:
- _delay_us(10);
+ 1) Select row
+ rowC ____~~~~____~~~~ 3.8/3.8ms(JP) 7.7/7.7ms(Pro) S2 of HC4051
+ rowB __~~__~~__~~__~~ 1.9/1.9ms(JP) 3.8/3.8ms(Pro) S1 of HC4051
+ rowA _~_~_~_~_~_~_~_~ 1.0/1.0ms(JP) 1.9/1.9ms(Pro) S0 of HC4051
+ 0123456701234567 selected row(Pro)
+ 0123456789ABCDEF selected row(JP)
+ rowEn0 ________~~~~~~~~ 7.7/7.7ms(JP only) ~Enable of Z2 HC4051(JP only)
+ rowEn1 ~~~~~~~~________ 7.7/7.7ms(JP only) ~Enable of Z3 HC4051(JP only)
- if (KEY == 0) { // read TP1684(KEY)
- // key pressed
- } else {
- // not pressed
- }
+ 2) Select column
+ colC ____~~~~____~~~~ 550/410us(JP) / us(Pro)
+ colB __~~__~~__~~__~~ 200/210us(JP) 450/460us(Pro)
+ colA _~_~_~_~_~_~_~_~ 100/110us(JP) 220/230us(Pro)
+ 0123456701234567 selected column
- KEY_PREV_OFF;
- UNALBLE_COL(); // set LS145(D) to high
+ 3) Wait 5us after column select, then set prev, strobe colD to spit out key status and read it.
+ prev _~~~~_____ 20us if previous key state is low
+ colD ~~~__~~~~~ 10us strobe
+ key ~~~____~~~ 22us indicates current state of the key
- _delay_us(150);
- }
- }
+ NOTE: JP scans twice fast as Pro/Pro2 does. So Pro/Pro2 scans 8x8 matrix in 15.4ms while JP scans 16x8 in that time.