qmk_firmware/keyboards/geistmaschine/macropod/matrix.c

88 lines
No EOL
2.8 KiB
C

/* Copyright 2023 ebastler and elpekenin
*
* 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 "matrix.h"
#include "pca9555.h"
#include "timer.h"
// PCA9555 i2c address, 0x20: A0 = 0, A1 = 0, A2 = 0
#define IC1 0x20
// Define how long to wait to reach the IO expander after connection loss again
// Since this board is modular, it should not spam unnecessary i2c requests if used without a module
#define RETRY_TIMESPAN 2000
typedef enum {
PLUGGED,
DOUBTFUL,
UNPLUGGED
} expander_status_t;
void pca9555_setup(void) {
// Initialize the expander, no need to set ports to inputs as that is the default behavior
pca9555_init(IC1);
}
void matrix_init_custom(void) {
// Encoder pushbutton on the MCU is connected to PD2
setPinInputHigh(D2);
pca9555_setup();
}
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
static expander_status_t status = DOUBTFUL;
static uint32_t retry_timer = 0;
// initialize one byte filled with 1
uint8_t pin_states = 0xFF;
if (status != UNPLUGGED || timer_elapsed32(retry_timer) > RETRY_TIMESPAN) {
// If the chip was unplugged before, it needs to be re-initialized
if(status==UNPLUGGED) {
pca9555_setup();
}
// Read the entire port into this byte, 1 = not pressed, 0 = pressed
bool ret = pca9555_read_pins(IC1, PCA9555_PORT0, &pin_states);
// Update state
if (ret) {
status = PLUGGED;
} else {
switch (status) {
case PLUGGED:
status = DOUBTFUL;
break;
case DOUBTFUL:
status = UNPLUGGED;
break;
// If we've diagnosed as unplugged, update timer to not read I2C
case UNPLUGGED:
retry_timer = timer_read32();
}
}
}
// Shift pin states by 1 to make room for the switch connected to the MCU, then OR them together and invert (as QMK uses inverted logic compared to the electrical levels)
matrix_row_t data = ~(pin_states << 1 | readPin(D2));
bool changed = current_matrix[0] != data;
current_matrix[0] = data;
return changed;
}