#ifndef I2C_H
#define I2C_H

// table 22-7 : prescale sets
#define TWI_PRESCALE_SET(value)  \
										((value) == 1  ? (0<<TWPS1 | 0<<TWPS0) : \
										 (value) == 4  ? (0<<TWPS1 | 1<<TWPS0) : \
										 (value) == 16 ? (1<<TWPS1 | 0<<TWPS0) : \
										 (value) == 64 ? (1<<TWPS1 | 1<<TWPS0) : 0x00)

// 22.7.1 : TWCR, Master Transmitter Mode
#define SEND_START_CONDITION			((1<<TWINT) | (1<<TWEN)) | (1<<TWSTA)
#define SEND_CONTINUE_TRANSMISSION		((1<<TWINT) | (1<<TWEN))
#define SEND_STOP_CONDITION				((1<<TWINT) | (1<<TWEN)) | (1<<TWSTO)
#define SEND_ACKNOWLEDGE				((1<<TWINT) | (1<<TWEN)  | (1<<TWEA))
#define SEND_NACKNOWLEDGE				((1<<TWINT) | (1<<TWEN))

#endif // I2C_H