iic.h

MEGA48单片机模拟/硬件两种方式实现TWI通讯

#ifndef IIC_H
#define IIC_H

void I2C_Write(void);
void I2C_Read(void);

#define TWI_ADDR                0xA2

/* TWSR values (not bits) */
/* Master */
#define I2C_START               0x08
#define I2C_RESTART             0x10

/* Master Transmitter */
#define I2C_MT_SLA_ACK          0x18
#define I2C_MT_SLA_NACK         0x20
#define I2C_MT_DATA_ACK         0x28
#define I2C_MT_DATA_NACK        0x30
#define I2C_MT_ARB_LOST         0x38

/* Master Receiver */
#define I2C_MR_ARB_LOST         0x38
#define I2C_MR_SLA_ACK          0x40
#define I2C_MR_SLA_NACK         0x48
#define I2C_MR_DATA_ACK         0x50
#define I2C_MR_DATA_NACK        0x58

/* Slave Transmitter */
#define I2C_ST_SLA_ACK          0xA8
#define I2C_ST_LOST_SLA_ACK     0xB0
#define I2C_ST_DATA_ACK         0xB8
#define I2C_ST_DATA_NACK        0xC0
#define I2C_ST_LAST_DATA        0xC8

/* Slave Receiver */
#define I2C_SR_SLA_ACK          0x60
#define I2C_SR_LOST_SLA_ACK     0x68
#define I2C_SR_GCALL_ACK        0x70
#define I2C_SR_LOST_GCALL_ACK   0x78
#define I2C_SR_DATA_ACK         0x80
#define I2C_SR_DATA_NACK        0x88
#define I2C_SR_GCALL_DATA_ACK   0x90
#define I2C_SR_GCALL_DATA_NACK  0x98
#define I2C_SR_STOP             0xA0

#define I2C_Start()       (TWCR = (BIT(TWINT)|BIT(TWSTA)|BIT(TWEN)))
#define I2C_Stop()        (TWCR = (BIT(TWINT)|BIT(TWSTO)|BIT(TWEN)))
#define I2C_Wait()        while(!(TESTMSK(TWCR,TWINT)))
#define I2C_ChkAck()      (TWSR&0xf8)     //check ack
#define I2C_SendByte(x)   (TWDR = (x),TWCR = BIT(TWINT)|BIT(TWEN)) 
#define I2C_RcvAckByte()  (TWCR = (BIT(TWINT)|BIT(TWEN)|BIT(TWEA)))

#endif