STM32F103 ARM GPIO模拟I2C的程序

#include "I2C.h" void I2C_delay1(void) { u32 i; for(i=0; i<10000;i++); } void I2C_delay(void) { u8 i=100; //这里可以优化速度 ，经测试最低到5还能写入 while(i) { i--; } } bool I2C_Start(void) { SDA_H; SCL_H; I2C_delay(); if(!SDA_read)return FALSE; //SDA线为低电平则总线忙,退出 SDA_L; I2C_delay(); if(SDA_read) return FALSE; //SDA线为高电平则总线出错,退出 SDA_L; I2C_delay(); return TRUE; } void I2C_Stop(void) { SCL_L; I2C_delay(); SDA_L; I2C_delay(); SCL_H; I2C_delay(); SDA_H; I2C_delay(); } void I2C_Ack(void) { SCL_L; I2C_delay(); SDA_L; I2C_delay(); SCL_H; I2C_delay(); SCL_L; I2C_delay(); } void I2C_NoAck(void) { SCL_L; I2C_delay(); SDA_H; I2C_delay(); SCL_H; I2C_delay(); SCL_L; I2C_delay(); } bool I2C_WaitAck(void) //返回为:=1有ACK,=0无ACK { SCL_L; I2C_delay(); SDA_H; I2C_delay(); SCL_H; I2C_delay(); if(SDA_read) { SCL_L; return FALSE; } SCL_L; return TRUE; } void I2C_SendByte(u8 SendByte) //数据从高位到低位// { u8 i=8; while(i--) { SCL_L; I2C_delay(); if(SendByte&0x80) SDA_H; else SDA_L; SendByte<<=1; I2C_delay(); SCL_H; I2C_delay(); } SCL_L; } u8 I2C_ReceiveByte(void) //数据从高位到低位// { u8 i=8; u8 ReceiveByte=0; SDA_H; while(i--) { ReceiveByte<<=1; SCL_L; I2C_delay(); SCL_H; I2C_delay(); if(SDA_read) { ReceiveByte|=0x01; } } SCL_L; return ReceiveByte; } bool I2C_WriteByte(u8 addr, u8 write_byte) { if(!I2C_Start())return FALSE; I2C_SendByte(0xa0);//器件地址 if(!I2C_WaitAck()){I2C_Stop(); return FALSE;} I2C_SendByte(addr); //设置地址 I2C_WaitAck(); I2C_SendByte(write_byte); I2C_WaitAck(); I2C_Stop(); //注意：因为这里要等待EEPROM写完，可以采用查询或延时方式(10ms) I2C_delay1(); return TRUE; } u8 I2C_ReadCurrent(void) { u8 read_data; if(!I2C_Start())return FALSE; I2C_SendByte(0xa1);//器件地址 if(!I2C_WaitAck()){I2C_Stop(); return FALSE;} read_data = I2C_ReceiveByte(); I2C_Stop(); return read_data; } u8 I2C_ReadByte(u8 addr) { if(!I2C_Start())return FALSE; I2C_SendByte(0xa0);//器件地址 if(!I2C_WaitAck()){I2C_Stop(); return FALSE;} I2C_SendByte(addr); //设置地址 I2C_WaitAck(); return(I2C_ReadCurrent()); }