STM32 AT24C256驱动IO模拟

#include"AT24C256.h" void GPIO_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB,ENABLE); //使能GPIOB的时钟 GPIO_InitStructure.GPIO_Pin=SCL|SDA; GPIO_InitStructure.GPIO_Mode=GPIO_Mode_OUT;//输出 GPIO_InitStructure.GPIO_OType=GPIO_OType_PP; //推挽输出 // GPIO_InitStructure.GPIO_PuPd=GPIO_PuPd_NOPULL; //上拉 GPIO_InitStructure.GPIO_Speed=GPIO_Speed_100MHz; //高速GPIO GPIO_Init(GPIOB,&GPIO_InitStructure); SCL_H(); SDA_H(); } void delay2us(u32 nus) { u32 i; while (nus--) for (i = 11; i > 0; 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--; } } u8 I2C_Start(void) { SDA_OUT(); 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 SCL_L(); return TRUE; } void I2C_Stop(void) { SDA_OUT(); SCL_L(); SDA_L(); I2C_delay(); SCL_H(); I2C_delay(); SDA_H(); I2C_delay(); } void I2C_Ack(void) { SDA_OUT(); SCL_L(); SDA_L(); I2C_delay(); SCL_H(); I2C_delay(); SCL_L(); } void I2C_NoAck(void) { SDA_OUT(); SCL_L(); SDA_H(); I2C_delay(); SCL_H(); I2C_delay(); SCL_L(); } u8 I2C_WaitAck(void) { u8 ucErrTime=0; SDA_IN(); SCL_H();I2C_delay(); SDA_H();I2C_delay(); while(SDA_read) { ucErrTime++; if(ucErrTime>250) { I2C_Stop(); return FALSE; } } SCL_L(); return TRUE; } void I2C_SendByte(u8 SendByte) //数据从高位到低位// { u8 i; SDA_OUT(); SCL_L(); for(i=0;i<8;i++) { if(SendByte&0x80) SDA_H(); else SDA_L(); SendByte<<=1; I2C_delay(); SCL_H(); I2C_delay(); SCL_L(); I2C_delay(); } } u8 I2C_ReceiveByte(void) //数据从高位到低位// { u8 i; u8 ReceiveByte=0; SDA_IN(); for(i=0;i<8;i++) { SCL_L(); I2C_delay(); SCL_H(); ReceiveByte<<=1; I2C_delay(); if(SDA_read) { // ReceiveByte|=0x01; ReceiveByte++; } } return ReceiveByte; } u8 AT24CXX_ReadOneByte(u16 ReadAddr) { u8 temp=0; I2C_Start(); I2C_SendByte(0XA0); //发送写命令 I2C_WaitAck(); I2C_SendByte(ReadAddr>>8);//发送高地址 I2C_WaitAck(); I2C_SendByte(ReadAddr%256); //发送低地址 I2C_WaitAck(); I2C_Start(); I2C_SendByte(0XA1); //进入接收模式 I2C_WaitAck(); temp=I2C_ReceiveByte(); I2C_Stop();//产生一个停止条件 return temp; } void AT24CXX_WriteOneByte(u16 WriteAddr,u8 DataToWrite) { I2C_Start(); I2C_SendByte(0XA0); //发送写命令 I2C_WaitAck(); I2C_SendByte(WriteAddr>>8);//发送高地址 I2C_WaitAck(); I2C_SendByte(WriteAddr%256); //发送低地址 I2C_WaitAck(); I2C_SendByte(DataToWrite); //发送字节 I2C_WaitAck(); I2C_Stop();//产生一个停止条件 delay2us(100000); } void AT24CXX_Read(u16 ReadAddr,u8 *pBuffer,u16 NumToRead) { while(NumToRead) { *pBuffer++=AT24CXX_ReadOneByte(ReadAddr++); NumToRead--; } } void AT24CXX_Write(u16 WriteAddr,u8 *pBuffer,u16 NumToWrite) { while(NumToWrite--) { AT24CXX_WriteOneByte(WriteAddr,*pBuffer); WriteAddr++; pBuffer++; } } void AT24CXX_BufferWriter(u16 WriteAddr, u8 *pBuffer,u32 NumToWrite) { u32 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0; delay2us(50); Addr=WriteAddr % I2C_PageSize; count = I2C_PageSize-Addr; if(count>=NumToWrite){ AT24CXX_Write( WriteAddr,pBuffer,NumToWrite); Delay10us(10); } else { NumOfPage=(NumToWrite-count)/I2C_PageSize; NumOfSingle=(NumToWrite-count)%I2C_PageSize; AT24CXX_Write( WriteAddr,pBuffer,count); WriteAddr+=count; pBuffer+=count; while(NumOfPage--) { AT24CXX_Write( WriteAddr,pBuffer,I2C_PageSize); Delay10us(10); WriteAddr += I2C_PageSize; pBuffer += I2C_PageSize; } if(NumOfSingle !=0) { AT24CXX_Write( WriteAddr,pBuffer,NumOfSingle); Delay10us(10); } } Delay10us(10); }