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 62a378165..000000000 --- a/drivers/avr/i2c_slave.c +++ /dev/null | |||
| @@ -1,86 +0,0 @@ | |||
| 1 | /* Copyright (C) 2019 Elia Ritterbusch | ||
| 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 3 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 <https://www.gnu.org/licenses/>. | ||
| 15 | */ | ||
| 16 | /* Library made by: g4lvanix | ||
| 17 | * GitHub repository: https://github.com/g4lvanix/I2C-slave-lib | ||
| 18 | */ | ||
| 19 | |||
| 20 | #include <avr/io.h> | ||
| 21 | #include <util/twi.h> | ||
| 22 | #include <avr/interrupt.h> | ||
| 23 | #include <stdbool.h> | ||
| 24 | |||
| 25 | #include "i2c_slave.h" | ||
| 26 | |||
| 27 | volatile uint8_t i2c_slave_reg[I2C_SLAVE_REG_COUNT]; | ||
| 28 | |||
| 29 | static volatile uint8_t buffer_address; | ||
| 30 | static volatile bool slave_has_register_set = false; | ||
| 31 | |||
| 32 | void i2c_slave_init(uint8_t address) { | ||
| 33 | // load address into TWI address register | ||
| 34 | TWAR = address; | ||
| 35 | // set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt | ||
| 36 | TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN); | ||
| 37 | } | ||
| 38 | |||
| 39 | void i2c_slave_stop(void) { | ||
| 40 | // clear acknowledge and enable bits | ||
| 41 | TWCR &= ~((1 << TWEA) | (1 << TWEN)); | ||
| 42 | } | ||
| 43 | |||
| 44 | ISR(TWI_vect) { | ||
| 45 | uint8_t ack = 1; | ||
| 46 | |||
| 47 | switch (TW_STATUS) { | ||
| 48 | case TW_SR_SLA_ACK: | ||
| 49 | // The device is now a slave receiver | ||
| 50 | slave_has_register_set = false; | ||
| 51 | break; | ||
| 52 | |||
| 53 | case TW_SR_DATA_ACK: | ||
| 54 | // This device is a slave receiver and has received data | ||
| 55 | // First byte is the location then the bytes will be writen in buffer with auto-incriment | ||
| 56 | if (!slave_has_register_set) { | ||
| 57 | buffer_address = TWDR; | ||
| 58 | |||
| 59 | if (buffer_address >= I2C_SLAVE_REG_COUNT) { // address out of bounds dont ack | ||
| 60 | ack = 0; | ||
| 61 | buffer_address = 0; | ||
| 62 | } | ||
| 63 | slave_has_register_set = true; // address has been receaved now fill in buffer | ||
| 64 | } else { | ||
| 65 | i2c_slave_reg[buffer_address] = TWDR; | ||
| 66 | buffer_address++; | ||
| 67 | } | ||
| 68 | break; | ||
| 69 | |||
| 70 | case TW_ST_SLA_ACK: | ||
| 71 | case TW_ST_DATA_ACK: | ||
| 72 | // This device is a slave transmitter and master has requested data | ||
| 73 | TWDR = i2c_slave_reg[buffer_address]; | ||
| 74 | buffer_address++; | ||
| 75 | break; | ||
| 76 | |||
| 77 | case TW_BUS_ERROR: | ||
| 78 | // We got an error, reset i2c | ||
| 79 | TWCR = 0; | ||
| 80 | default: | ||
| 81 | break; | ||
| 82 | } | ||
| 83 | |||
| 84 | // Reset i2c state machine to be ready for next interrupt | ||
| 85 | TWCR |= (1 << TWIE) | (1 << TWINT) | (ack << TWEA) | (1 << TWEN); | ||
| 86 | } | ||
