matrix.c (4140B)
1 /* 2 Copyright 2017 Luiz Ribeiro <luizribeiro@gmail.com> 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation, either version 2 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 #include "matrix.h" 19 #include "i2c_master.h" 20 21 #define RIGHT_HALF 22 23 24 void matrix_set_row_status(uint8_t row); 25 26 27 #if defined(RIGHT_HALF) 28 #define I2C_TIMEOUT 10 29 #define MCP23018_TWI_ADDRESS 0b0100000 30 #define TW_READ 1 31 #define TW_WRITE 0 32 #define TWI_ADDR_WRITE ( (MCP23018_TWI_ADDRESS<<1) | TW_WRITE ) 33 #define TWI_ADDR_READ ( (MCP23018_TWI_ADDRESS<<1) | TW_READ ) 34 #define IODIRA 0x00 // i/o direction register 35 #define IODIRB 0x01 36 #define IODIRA 0x00 // i/o direction register 37 #define IODIRB 0x01 38 #define GPPUA 0x0C // GPIO pull-up resistor register 39 #define GPPUB 0x0D 40 #define GPIOA 0x12 // general purpose i/o port register (write modifies OLAT) 41 #define GPIOB 0x13 42 #define OLATA 0x14 // output latch register 43 #define OLATB 0x15 44 #define MCP_ROWS_START 8 45 46 static uint8_t mcp23018_init(void) { 47 uint8_t ret; 48 uint8_t data[3]; 49 // set pin direction 50 // - unused : input : 1 51 // - input : input : 1 52 // - driving : output : 0 53 data[0] = IODIRA; 54 data[1] = 0b00000000; // IODIRA 55 data[2] = (0b11111111); // IODIRB 56 57 ret = i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)data, 3, I2C_TIMEOUT); 58 if (ret) goto out; // make sure we got an ACK 59 60 // set pull-up 61 // - unused : on : 1 62 // - input : on : 1 63 // - driving : off : 0 64 data[0] = GPPUA; 65 data[1] = 0b00000000; // IODIRA 66 data[2] = (0b11111111); // IODIRB 67 68 ret = i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)data, 3, I2C_TIMEOUT); 69 if (ret) goto out; // make sure we got an ACK 70 71 // set logical value (doesn't matter on inputs) 72 // - unused : hi-Z : 1 73 // - input : hi-Z : 1 74 // - driving : hi-Z : 1 75 data[0] = OLATA; 76 data[1] = 0b11111111; // IODIRA 77 data[2] = (0b11111111); // IODIRB 78 79 ret = i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)data, 3, I2C_TIMEOUT); 80 81 out: 82 return ret; 83 } 84 #endif 85 86 void matrix_init_custom(void) { 87 // Set rows as output starting high 88 DDRB = 0xFF; 89 PORTB = 0xFF; 90 91 // Set columns as inputs with pull-up enabled 92 DDRA = 0x00; 93 PORTA = 0xFF; 94 95 // Initialize i2c communication 96 i2c_init(); 97 98 #if defined(RIGHT_HALF) 99 // Initialize the chip on the other half 100 mcp23018_init(); 101 #endif 102 103 } 104 105 bool matrix_scan_custom(matrix_row_t current_matrix[]) { 106 bool matrix_has_changed = false; 107 108 for (uint8_t row = 0; row < MATRIX_ROWS; row++) { 109 // Store last value of row prior to reading 110 matrix_row_t last_row_value = current_matrix[row]; 111 112 matrix_row_t cols = 0; 113 // Select the row to scan 114 matrix_set_row_status(row); 115 116 matrix_io_delay(); 117 //Set the local row 118 119 #if defined(RIGHT_HALF) 120 // Initialize to 0x7F in case I2C read fails, 121 // as 0x75 would be no keys pressed 122 uint8_t data = 0x7F; 123 // Receive the columns from right half 124 i2c_receive(TWI_ADDR_WRITE, &data, 1, I2C_TIMEOUT); 125 #endif 126 127 cols |= ((~(PINA | 0x80)) & 0x7F); 128 #if defined(RIGHT_HALF) 129 cols |= (((~(data | 0x80)) & 0x7F) << 7); 130 #endif 131 132 current_matrix[row] = cols; 133 matrix_has_changed |= (last_row_value != current_matrix[row]); 134 } 135 136 return matrix_has_changed; 137 } 138 139 void matrix_set_row_status(uint8_t row) { 140 #if defined(RIGHT_HALF) 141 uint8_t txdata[3]; 142 143 //Set the remote row on port A 144 txdata[0] = (GPIOA); 145 txdata[1] = ( 0xFF & ~(1<<row) ); 146 i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)txdata, 2, I2C_TIMEOUT); 147 #endif 148 149 //Set the local row on port B 150 DDRB = (1 << row); 151 PORTB = ~(1 << row); 152 }