diff options
Diffstat (limited to 'drivers/avr/i2c_slave.c')
-rw-r--r-- | drivers/avr/i2c_slave.c | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/drivers/avr/i2c_slave.c b/drivers/avr/i2c_slave.c deleted file mode 100644 index 62a378165a..0000000000 --- a/drivers/avr/i2c_slave.c +++ /dev/null @@ -1,86 +0,0 @@ -/* Copyright (C) 2019 Elia Ritterbusch - + - * 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 3 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 <https://www.gnu.org/licenses/>. - */ -/* Library made by: g4lvanix - * GitHub repository: https://github.com/g4lvanix/I2C-slave-lib - */ - -#include <avr/io.h> -#include <util/twi.h> -#include <avr/interrupt.h> -#include <stdbool.h> - -#include "i2c_slave.h" - -volatile uint8_t i2c_slave_reg[I2C_SLAVE_REG_COUNT]; - -static volatile uint8_t buffer_address; -static volatile bool slave_has_register_set = false; - -void i2c_slave_init(uint8_t address) { - // load address into TWI address register - TWAR = address; - // set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt - TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN); -} - -void i2c_slave_stop(void) { - // clear acknowledge and enable bits - TWCR &= ~((1 << TWEA) | (1 << TWEN)); -} - -ISR(TWI_vect) { - uint8_t ack = 1; - - switch (TW_STATUS) { - case TW_SR_SLA_ACK: - // The device is now a slave receiver - slave_has_register_set = false; - break; - - case TW_SR_DATA_ACK: - // This device is a slave receiver and has received data - // First byte is the location then the bytes will be writen in buffer with auto-incriment - if (!slave_has_register_set) { - buffer_address = TWDR; - - if (buffer_address >= I2C_SLAVE_REG_COUNT) { // address out of bounds dont ack - ack = 0; - buffer_address = 0; - } - slave_has_register_set = true; // address has been receaved now fill in buffer - } else { - i2c_slave_reg[buffer_address] = TWDR; - buffer_address++; - } - break; - - case TW_ST_SLA_ACK: - case TW_ST_DATA_ACK: - // This device is a slave transmitter and master has requested data - TWDR = i2c_slave_reg[buffer_address]; - buffer_address++; - break; - - case TW_BUS_ERROR: - // We got an error, reset i2c - TWCR = 0; - default: - break; - } - - // Reset i2c state machine to be ready for next interrupt - TWCR |= (1 << TWIE) | (1 << TWINT) | (ack << TWEA) | (1 << TWEN); -} |