qmk_firmware/keyboards/ydkb/grape/matrix.c
somepin 7e0dde1f00
[Keyboard] Add YDKB Grape PCB (#16661)
Co-authored-by: Drashna Jaelre <drashna@live.com>
2022-03-25 17:45:35 -07:00

97 lines
2.6 KiB
C

/*
Copyright 2022 somepin
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 col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
/* All rows use a 74HC138 3 to 8 bit demultiplexer.
*
* A2 A1 A0
* D0 D1 D2
* 0: 0 0 0
* 1: 0 0 1
* 2: 0 1 0
* 3: 0 1 1
* 4: 1 0 0
* 5: 1 0 1
* 6: 1 1 0
*/
static void select_row(uint8_t row) {
sn74x138_set_addr(row);
}
static void init_pins(void) {
for (uint8_t x = 0; x < MATRIX_COLS; x++) {
setPinInputHigh(col_pins[x]);
}
}
static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
bool matrix_changed = false;
// Store last value of row prior to reading
matrix_row_t last_row_value = current_matrix[current_row];
// Start with a clear matrix row
current_matrix[current_row] = 0;
// Select row and wait for row selection to stabilize
select_row(current_row);
matrix_io_delay();
// For each col...
matrix_row_t row_shifter = MATRIX_ROW_SHIFTER;
for (uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
// Select the col pin to read (active low)
uint8_t pin_state = readPin(col_pins[col_index]);
// Populate the matrix row with the state of the col pin
current_matrix[current_row] |= pin_state ? 0 : (row_shifter << col_index);
}
// Determine if matrix changed state
if ((last_row_value != current_matrix[current_row]) && !(matrix_changed)) {
matrix_changed = true;
}
return matrix_changed;
}
void matrix_init_custom(void) {
// initialize demultiplexer
sn74x138_init();
// initialize key pins
init_pins();
}
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
bool changed = false;
// Set row, read cols
for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
changed |= read_cols_on_row(current_matrix, current_row);
}
return changed;
}