mirror of
https://github.com/mfulz/qmk_firmware.git
synced 2025-11-03 23:02:34 +01:00
37932c293c
* Update split_common to use standard i2c drivers * Eliminate RGB_DIRTY/BACKLIT_DIRTY * Fix avr i2c_master error handling * Fix i2c_slave addressing * Remove unneeded timeout on i2c_stop() * Fix RGB I2C transfers * Remove incorrect comment
71 lines
2.1 KiB
C
Executable File
71 lines
2.1 KiB
C
Executable File
/* 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);
|
|
} |