qmk_firmware

QMK firmware for my keyboards (Corne, Sweep Ferris) and trackball (Ploopy Adept)
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matrix.c (2871B)

      1 /* Copyright 2023 ebastler and elpekenin
      2  *
      3  * This program is free software: you can redistribute it and/or modify
      4  * it under the terms of the GNU General Public License as published by
      5  * the Free Software Foundation, either version 2 of the License, or
      6  * (at your option) any later version.
      7  *
      8  * This program is distributed in the hope that it will be useful,
      9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     11  * GNU General Public License for more details.
     12  *
     13  * You should have received a copy of the GNU General Public License
     14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
     15  */
     16 
     17 #include "matrix.h"
     18 #include "pca9555.h"
     19 #include "timer.h"
     20 
     21 // PCA9555 i2c address, 0x20: A0 = 0, A1 = 0, A2 = 0
     22 #define IC1 0x20
     23 
     24 // Define how long to wait to reach the IO expander after connection loss again
     25 // Since this board is modular, it should not spam unnecessary i2c requests if used without a module
     26 #define RETRY_TIMESPAN 2000
     27 
     28 typedef enum {
     29     PLUGGED,
     30     DOUBTFUL,
     31     UNPLUGGED
     32 } expander_status_t;
     33 
     34 void pca9555_setup(void) {
     35     // Initialize the expander, no need to set ports to inputs as that is the default behavior
     36     pca9555_init(IC1);
     37 }
     38 
     39 void matrix_init_custom(void) {
     40     // Encoder pushbutton on the MCU is connected to PD2
     41     gpio_set_pin_input_high(D2);
     42     pca9555_setup();
     43 }
     44 
     45 bool matrix_scan_custom(matrix_row_t current_matrix[]) {
     46     static expander_status_t status      = DOUBTFUL;
     47     static uint32_t          retry_timer = 0;
     48 
     49     // initialize one byte filled with 1
     50     uint8_t pin_states = 0xFF;
     51     
     52     
     53     if (status != UNPLUGGED || timer_elapsed32(retry_timer) > RETRY_TIMESPAN) {
     54         // If the chip was unplugged before, it needs to be re-initialized
     55         if(status==UNPLUGGED) {
     56             pca9555_setup();
     57         }
     58         // Read the entire port into this byte, 1 = not pressed, 0 = pressed
     59         bool ret = pca9555_read_pins(IC1, PCA9555_PORT0, &pin_states);
     60 
     61         // Update state
     62         if (ret) {
     63             status = PLUGGED;
     64         } else {
     65             switch (status) {
     66                 case PLUGGED:
     67                     status = DOUBTFUL;
     68                     break;
     69 
     70                 case DOUBTFUL:
     71                     status = UNPLUGGED;
     72                     break;
     73 
     74                 // If we've diagnosed as unplugged, update timer to not read I2C
     75                 case UNPLUGGED:
     76                     retry_timer = timer_read32();
     77             }
     78         }
     79     }
     80 
     81     // 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)
     82     matrix_row_t data = ~(pin_states << 1 | gpio_read_pin(D2));
     83 
     84     bool changed = current_matrix[0] != data;
     85     current_matrix[0] = data;
     86 
     87     return changed;
     88 }