matrix.c (3740B)
1 // Copyright 2019 Mathias Andersson <wraul@dbox.se> 2 // SPDX-License-Identifier: GPL-2.0-or-later 3 #include "matrix.h" 4 #include "pca9555.h" 5 #include "wait.h" 6 7 /* 8 * IC1 (PCA9555) IC2 (PCA9555) 9 * ,----------. ,----------. 10 * SDA --| SDA P00 |-- P1 SDA --| SDA P00 |-- P17 11 * SCL --| SCL P01 |-- P2 SCL --| SCL P01 |-- P18 12 * INT --| INT P02 |-- P3 INT --| INT P02 |-- P19 13 * | P03 |-- P4 | P03 |-- P20 14 * GND --| A0 P04 |-- P5 VCC --| A0 P04 |-- P21 15 * SJ1 --| A1 P05 |-- P6 SJ1 --| A1 P05 |-- P22 16 * GND --| A2 P06 |-- P7 GND --| A2 P06 |-- P23 17 * | P07 |-- P8 | P07 |-- P24 18 * | | | | 19 * | P10 |-- P9 | P10 |-- P25 20 * | P11 |-- P10 | P11 |-- P26 21 * | P12 |-- P11 | P12 |-- P27 22 * | P13 |-- P12 | P13 |-- P28 23 * | P14 |-- P13 | P14 |-- P29 24 * | P15 |-- P14 | P15 |-- P30 25 * | P16 |-- P15 | P16 |-- P31 26 * | P17 |-- P16 | P17 |-- P32 27 * `----------' `----------' 28 */ 29 30 /* 31 * | Row | Pin | | Col | Pin | 32 * | --- | --- | | --- | --- | 33 * | 0 | P1 | | 0 | P25 | 34 * | 1 | P2 | | 1 | P26 | 35 * | 2 | P3 | | 2 | P27 | 36 * | 3 | P4 | | 3 | P28 | 37 * | 4 | P5 | | 4 | P29 | 38 * | 5 | P6 | | 5 | P30 | 39 * | 6 | P7 | | 6 | P20 | 40 * | 7 | P8 | | 7 | P21 | 41 * | 8 | P22 | 42 * | 9 | P23 | 43 * | A | P24 | 44 */ 45 46 // PCA9555 slave addresses 47 #define IC1 0x20 48 #define IC2 0x21 49 50 // PCA9555 column pin masks 51 #define PORT0_COLS_MASK 0b11111000 52 #define PORT1_COLS_MASK 0b00111111 53 #define COLS_MASK 0b0000011111111111 54 55 static void init_pins(void) { 56 // init cols - IC2 port0 & IC2 port1 input 57 pca9555_set_config(IC2, PCA9555_PORT0, ALL_INPUT); 58 pca9555_set_config(IC2, PCA9555_PORT1, ALL_INPUT); 59 60 // init rows - IC1 port0 output 61 pca9555_set_config(IC1, PCA9555_PORT0, ALL_OUTPUT); 62 pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH); 63 } 64 65 static void select_row(uint8_t row) { 66 // All rows are on the same IC and port 67 uint8_t mask = 1 << row; 68 69 // set active row low : 0 70 // set other rows hi-Z : 1 71 pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH & (~mask)); 72 } 73 74 static uint16_t read_cols(void) { 75 uint8_t state_1 = 0; 76 uint8_t state_2 = 0; 77 pca9555_read_pins(IC2, PCA9555_PORT0, &state_1); 78 pca9555_read_pins(IC2, PCA9555_PORT1, &state_2); 79 80 uint16_t state = (((uint16_t)state_1 & PORT0_COLS_MASK) << 3) | (((uint16_t)state_2 & PORT1_COLS_MASK)); 81 82 // A low pin indicates an active column 83 return (~state) & COLS_MASK; 84 } 85 86 static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) { 87 // Store last value of row prior to reading 88 matrix_row_t last_row_value = current_matrix[current_row]; 89 90 // Clear data in matrix row 91 current_matrix[current_row] = 0; 92 93 // Select row and wait for row selection to stabilize 94 select_row(current_row); 95 wait_us(30); 96 97 current_matrix[current_row] = read_cols(); 98 99 // No need to unselect as `select_row` sets all the pins. 100 101 return (last_row_value != current_matrix[current_row]); 102 } 103 104 void matrix_init_custom(void) { 105 pca9555_init(IC1); 106 pca9555_init(IC2); 107 108 init_pins(); 109 } 110 111 bool matrix_scan_custom(matrix_row_t current_matrix[]) { 112 bool changed = false; 113 for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) { 114 changed |= read_cols_on_row(current_matrix, current_row); 115 } 116 return changed; 117 }