/* 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 . */ #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; }