summaryrefslogtreecommitdiffstats
path: root/keyboards/evyd13/wasdat/matrix.c
blob: c97dd846944478a37de123df7c8a4a0c184685e6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/*
Copyright 2012-2018 Jun Wako, Jack Humbert, Yiancar

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdint.h>
#include <stdbool.h>
#include "matrix.h"
#include "quantum.h"
#include "sn74x138.h"

static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;

/* col 0: C7
 * col 1: B6
 * col 2: C6
 * col 3: B4
 * col 4: B5
 * col 5: D7
 *
 * These columns use a 74HC138 3 to 8 bit demultiplexer.
 *                A2   A1   A0
 * col / pin:    PD0  PD1  PD2
 * 6:              1    1    1
 * 7:              1    1    0
 * 8:              1    0    1
 * 9:              1    0    0
 * 10:             0    1    1
 * 11:             0    1    0
 * 12:             0    0    1
 *
 * col 13: D3
 * col 14: B7
 * col 15: B3
 */
static void select_col(uint8_t col) {
    if (col_pins[col] != NO_PIN) {
        writePinLow(col_pins[col]);
    } else {
        sn74x138_set_addr(13 - col);
    }
}

static void unselect_col(uint8_t col) {
    if (col_pins[col] != NO_PIN) {
        setPinOutput(col_pins[col]);
        writePinHigh(col_pins[col]);
    } else {
        sn74x138_set_addr(0);
    }
}

static void unselect_cols(void) {
    // Native
    for (uint8_t x = 0; x < MATRIX_COLS; x++) {
        if (col_pins[x] != NO_PIN) {
            setPinOutput(col_pins[x]);
            writePinHigh(col_pins[x]);
        }
    }

    // Demultiplexer
    sn74x138_set_addr(0);
}

static void init_pins(void) {
    unselect_cols();
    for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
        setPinInputHigh(row_pins[x]);
    }
}

static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
    bool matrix_changed = false;

    // Select col and wait for col selection to stabilize
    select_col(current_col);
    matrix_io_delay();

    // For each row...
    for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) {
        // Store last value of row prior to reading
        matrix_row_t last_row_value = current_matrix[row_index];

        // Check row pin state
        if (readPin(row_pins[row_index]) == 0) {
            // Pin LO, set col bit
            current_matrix[row_index] |= (MATRIX_ROW_SHIFTER << current_col);
        } else {
            // Pin HI, clear col bit
            current_matrix[row_index] &= ~(MATRIX_ROW_SHIFTER << current_col);
        }

        // Determine if the matrix changed state
        if ((last_row_value != current_matrix[row_index]) && !(matrix_changed)) {
            matrix_changed = true;
        }
    }

    // Unselect col
    unselect_col(current_col);

    return matrix_changed;
}

void matrix_init_custom(void) {
    // initialize key pins
    init_pins();
    // initialize demultiplexer
    sn74x138_init();
}

bool matrix_scan_custom(matrix_row_t current_matrix[]) {
    bool changed = false;

    // Set col, read rows
    for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
        changed |= read_rows_on_col(current_matrix, current_col);
    }

    return changed;
}