自用模拟I2C的实现

1.头文件#define GPIO_PIN_X #define SDA_IN GPIO-PortC_OutputEN | GPIO_PIN_X;gpio_set_portpull(GPIO_C,GPIO_PIN_X,GPIO_NOPULL); #define SDA_OUT GPIO-PortC_OutputEN ~ GPIO_PIN_X; #define SDA_DATA() gpio_read_pin(GPIO_C, GPIO_PIN_X) #define SDA_H gpio_write_pin(GPIO_C, GPIO_PIN_X, GPIO_PIN_SET) #define SDA_L gpio_write_pin(GPIO_C, GPIO_PIN_X, GPIO_PIN_CLEAR) // IIC所有操作函数 void IIC_Start(void); void IIC_Stop(void); uint8_t IIC_Wait_Ack(void); void IIC_Put_Ack(uint8_t Ack); void IIC_Send_Byte(char Data); uint8_t IIC_Read_Byte(void); unsigned char I2C_WriteByte(uint8_t Master_addr, uint8_t Send_addr, uint8_t data); unsigned char I2C_ReadByte(uint8_t Master_addr, uint8_t Send_addr); unsigned char I2CWrite_Sequence(uint8_t Master_addr, uint8_t *wit_data, uint8_t sequence_length); unsigned char I2CRead_Sequence(uint8_t Master_addr, uint8_t *reg_value, uint8_t sequence_length);2.源码/************************************模拟I2C******************************************/ #define I2C_Delay_Time 5 // 10us // 产生IIC起始信号 void IIC_Start(void) { SDA_OUT; SCL_H; I2Cdelay(I2C_Delay_Time); SDA_H; I2Cdelay(I2C_Delay_Time); SDA_L; I2Cdelay(I2C_Delay_Time); SCL_L; I2Cdelay(I2C_Delay_Time); } // 产生IIC停止信号 void IIC_Stop(void) { SDA_OUT; SDA_L; I2Cdelay(I2C_Delay_Time); SCL_H; I2Cdelay(I2C_Delay_Time); SDA_H; I2Cdelay(I2C_Delay_Time); } // 等待数据接收方反馈ACK // 成功返回0 失败返回1 uint8_t IIC_Wait_Ack(void) { uint16_t wait_time 0; uint8_t ack_nack 0; SCL_L; I2Cdelay(I2C_Delay_Time); SDA_IN; // 释放总线 等待从机拉低 I2Cdelay(I2C_Delay_Time); SCL_H; I2Cdelay(I2C_Delay_Time); while (SDA_DATA()) { wait_time; if (wait_time 200) // 时间过长 退出等待 { ack_nack 1; break; } } SCL_L; SDA_OUT; I2Cdelay(I2C_Delay_Time); return ack_nack; } // 产生ACK应答 // 发送ACK就是在SDA0时 SCL由0变成1 // 发送NACK就是在SDA1时SCL由0变成1 void IIC_Put_Ack(uint8_t Ack) { SDA_OUT; I2Cdelay(I2C_Delay_Time); if (Ack 0) SDA_L; // 应答ACK else SDA_H; // 无应答NACK I2Cdelay(I2C_Delay_Time); SCL_H; I2Cdelay(I2C_Delay_Time); SCL_L; I2Cdelay(I2C_Delay_Time); } // 主设备发送一个字节 void IIC_Send_Byte(char Data) { char i; SDA_OUT; for (i 0; i 8; i) { SCL_L; if (Data 0x80) SDA_H; else SDA_L; Data Data 1; I2Cdelay(I2C_Delay_Time); SCL_H; I2Cdelay(I2C_Delay_Time); } SCL_L; I2Cdelay(I2C_Delay_Time); } // 主设备从从设备读一个字节 uint8_t IIC_Read_Byte(void) { uint8_t i, Data; SCL_L; SDA_IN; // 将SDA设置为输入 I2Cdelay(I2C_Delay_Time); for (i 0; i 8; i) { SCL_H; Data 1; if (SDA_DATA()) Data | 0x01; else Data 0xFE; I2Cdelay(I2C_Delay_Time); SCL_L; I2Cdelay(I2C_Delay_Time); } SDA_OUT; return Data; } // I2C主设备数据发送 // 有应答 0 失败 1 unsigned char I2C_WriteByte(uint8_t Master_addr, uint8_t Send_addr, uint8_t data) { IIC_Start(); IIC_Send_Byte(((Master_addr 1) 0xFE)); // I2C7位地址 if (IIC_Wait_Ack() 0) return 1; IIC_Send_Byte(Send_addr); if (IIC_Wait_Ack() 0) return 1; IIC_Send_Byte(data); if (IIC_Wait_Ack() 0) return 1; IIC_Stop(); return 0; } // I2C主设备数据读取 // 有应答data 失败 1 unsigned char I2C_ReadByte(uint8_t Master_addr, uint8_t Send_addr) // 读寄存器或读数据 { unsigned char reg_value; IIC_Start(); IIC_Send_Byte(((Master_addr 1) 0xFE)); // 主设备地址 if (IIC_Wait_Ack()) return 1; IIC_Send_Byte(Send_addr); if (IIC_Wait_Ack()) return 1; IIC_Start(); IIC_Send_Byte(((Master_addr 1) | 0x01)); // 读器件地址 if (IIC_Wait_Ack()) return 1; reg_value IIC_Read_Byte(); IIC_Stop(); return reg_value; } // I2C的连续写 unsigned char I2CWrite_Sequence(uint8_t slave_addr, uint8_t reg_addr, uint8_t *write_data, uint8_t data_len) { unsigned char i; IIC_Start(); // 发送写器件地址 IIC_Send_Byte(slave_addr 1); if (IIC_Wait_Ack()) { IIC_Stop(); return 1; } // 发送寄存器起始地址 IIC_Send_Byte(reg_addr); if (IIC_Wait_Ack()) { IIC_Stop(); return 2; } // 连续发送数据 for (i 0; i data_len; i) { IIC_Send_Byte(write_data[i]); if (IIC_Wait_Ack()) { IIC_Stop(); return 3; } } IIC_Stop(); return 0; } // I2C的连续读 unsigned char I2CRead_Sequence(uint8 slave_addr, uint8 reg_addr, uint8 *reg_value, uint8 sequence_length) { unsigned char i; IIC_Start(); // 写器件地址 IIC_Send_Byte(slave_addr 1); if (IIC_Wait_Ack()) { IIC_Stop(); return 1; } // 写寄存器地址 IIC_Send_Byte(reg_addr); if (IIC_Wait_Ack()) { IIC_Stop(); return 1; } // 重复起始条件 IIC_Start(); // 读器件地址 IIC_Send_Byte((slave_addr 1) | 0x01); if (IIC_Wait_Ack()) { IIC_Stop(); return 1; } // 读取数据 for (i 0; i sequence_length; i) { reg_value[i] IIC_Read_Byte(); if (i sequence_length - 1) IIC_Put_Ack(0); // ACK else IIC_Put_Ack(1); // NACK } IIC_Stop(); return 0; } void I2Cdelay(int time) { co_delay_10us(time); }