164 lines
4.4 KiB
C
164 lines
4.4 KiB
C
/*
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Copyright 2017 Luiz Ribeiro <luizribeiro@gmail.com>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "matrix.h"
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#include "i2c_master.h"
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#define RIGHT_HALF
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void matrix_set_row_status(uint8_t row);
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#if defined(RIGHT_HALF)
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#define I2C_TIMEOUT 10
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#define MCP23018_TWI_ADDRESS 0b0100000
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#define TW_READ 1
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#define TW_WRITE 0
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#define TWI_ADDR_WRITE ( (MCP23018_TWI_ADDRESS<<1) | TW_WRITE )
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#define TWI_ADDR_READ ( (MCP23018_TWI_ADDRESS<<1) | TW_READ )
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#define IODIRA 0x00 // i/o direction register
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#define IODIRB 0x01
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#define IODIRA 0x00 // i/o direction register
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#define IODIRB 0x01
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#define GPPUA 0x0C // GPIO pull-up resistor register
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#define GPPUB 0x0D
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#define GPIOA 0x12 // general purpose i/o port register (write modifies OLAT)
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#define GPIOB 0x13
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#define OLATA 0x14 // output latch register
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#define OLATB 0x15
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#define MCP_ROWS_START 8
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static uint8_t mcp23018_init(void) {
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uint8_t ret;
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uint8_t data[3];
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// set pin direction
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// - unused : input : 1
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// - input : input : 1
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// - driving : output : 0
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data[0] = IODIRA;
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data[1] = 0b00000000; // IODIRA
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data[2] = (0b11111111); // IODIRB
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ret = i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)data, 3, I2C_TIMEOUT);
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if (ret) goto out; // make sure we got an ACK
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// set pull-up
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// - unused : on : 1
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// - input : on : 1
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// - driving : off : 0
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data[0] = GPPUA;
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data[1] = 0b00000000; // IODIRA
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data[2] = (0b11111111); // IODIRB
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ret = i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)data, 3, I2C_TIMEOUT);
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if (ret) goto out; // make sure we got an ACK
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// set logical value (doesn't matter on inputs)
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// - unused : hi-Z : 1
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// - input : hi-Z : 1
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// - driving : hi-Z : 1
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data[0] = OLATA;
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data[1] = 0b11111111; // IODIRA
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data[2] = (0b11111111); // IODIRB
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ret = i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)data, 3, I2C_TIMEOUT);
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out:
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return ret;
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}
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#endif
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void matrix_init_custom(void) {
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// Set rows as output starting high
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DDRB = 0xFF;
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PORTB = 0xFF;
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// Set columns as inputs with pull-up enabled
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DDRA = 0x00;
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PORTA = 0xFF;
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// Initialize i2c communication
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i2c_init();
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#if defined(RIGHT_HALF)
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// Initialize the chip on the other half
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mcp23018_init();
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#endif
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}
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static i2c_status_t mcp23018_status = I2C_STATUS_SUCCESS;
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bool matrix_scan_custom(matrix_row_t current_matrix[]) {
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bool matrix_has_changed = false;
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#if defined(RIGHT_HALF)
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if (mcp23018_status != I2C_STATUS_SUCCESS) {
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mcp23018_status = mcp23018_init();
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}
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#endif
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for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
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// Store last value of row prior to reading
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matrix_row_t last_row_value = current_matrix[row];
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matrix_row_t cols = 0;
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// Select the row to scan
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matrix_set_row_status(row);
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matrix_io_delay();
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//Set the local row
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#if defined(RIGHT_HALF)
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// Initialize to 0x7F in case I2C read fails,
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// as 0x75 would be no keys pressed
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uint8_t data = 0x7F;
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// Receive the columns from right half
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if (mcp23018_status == I2C_STATUS_SUCCESS) {
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mcp23018_status = i2c_receive(TWI_ADDR_WRITE, &data, 1, I2C_TIMEOUT);
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}
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#endif
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cols |= ((~(PINA | 0x80)) & 0x7F);
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#if defined(RIGHT_HALF)
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cols |= (((~(data | 0x80)) & 0x7F) << 7);
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#endif
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current_matrix[row] = cols;
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matrix_has_changed |= (last_row_value != current_matrix[row]);
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}
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return matrix_has_changed;
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}
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void matrix_set_row_status(uint8_t row) {
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#if defined(RIGHT_HALF)
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uint8_t txdata[3];
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//Set the remote row on port A
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txdata[0] = (GPIOA);
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txdata[1] = ( 0xFF & ~(1<<row) );
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if (mcp23018_status == I2C_STATUS_SUCCESS) {
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mcp23018_status = i2c_transmit(TWI_ADDR_WRITE, (uint8_t *)txdata, 2, I2C_TIMEOUT);
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}
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#endif
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//Set the local row on port B
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DDRB = (1 << row);
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PORTB = ~(1 << row);
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}
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