/* Includes ------------------------------------------------------------------*/
#include <includes.h>
#define IIC_SCL_SET() (GPIOB->BSRRL = GPIO_Pin_10)
#define IIC_SCL_CLR() (GPIOB->BSRRH = GPIO_Pin_10)
#define IIC_SDA_SET() (GPIOB->BSRRL = GPIO_Pin_11)
#define IIC_SDA_CLR() (GPIOB->BSRRH = GPIO_Pin_11)
#define IIC_SDA_READ() (GPIOB->IDR & GPIO_Pin_11)
#define IIC_SDA_IN() {GPIOB->MODER &= ~(GPIO_MODER_MODER0 << (11 * 2)); GPIOB->MODER |= (((uint32_t)GPIO_Mode_IN) << (11 * 2));}
#define IIC_SDA_OUT() {GPIOB->MODER &= ~(GPIO_MODER_MODER0 << (11 * 2)); GPIOB->MODER |= (((uint32_t)GPIO_Mode_OUT) << (11 * 2));}
//#define IIC_SDA_DIR(dir) ( GPIOB->MODER &= ~(GPIO_MODER_MODER0 << (GPIO_Pin_11 * 2)); GPIOB->MODER |= (((uint32_t)1) << (GPIO_Pin_11 * 2)); )
void delay_us(u32 nus)
{
u32 ticks;
u32 told,tnow,tcnt=0;
u32 reload=SysTick->LOAD; //LOAD的值
ticks=nus*21; //需要的节拍数
tcnt=0;
told=SysTick->VAL; //刚进入时的计数器值
while(1)
{
tnow=SysTick->VAL;
if(tnow!=told)
{
if(tnow<told)tcnt+=told-tnow;//这里注意一下SYSTICK是一个递减的计数器就可以了.
else tcnt+=reload-tnow+told;
told=tnow;
if(tcnt>=ticks)break;//时间超过/等于要延迟的时间,则退出.
}
};
}
uint8_t I2C_ReadKey(void)
{
return Key_Get();
}
//初始化IIC
void IIC_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10|GPIO_Pin_11;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_SetBits(GPIOB,GPIO_Pin_10|GPIO_Pin_11); //PB10,PB11 输出高
}
//产生IIC起始信号
void IIC_Start(void)
{
IIC_SDA_OUT();
IIC_SDA_SET();
IIC_SCL_SET();
delay_us(4);
IIC_SDA_CLR();//START:when CLK is high,DATA change form high to low
delay_us(4);
IIC_SCL_CLR();;//钳住I2C总线，准备发送或接收数据
}
//产生IIC停止信号
void IIC_Stop(void)
{
IIC_SDA_OUT();//sda线输出
IIC_SCL_CLR();
IIC_SDA_CLR();//STOP:when CLK is high DATA change form low to high
delay_us(4);
IIC_SCL_SET();
IIC_SDA_SET();//发送I2C总线结束信号
delay_us(4);
}
//等待应答信号到来
//返回值：1，接收应答失败
// 0，接收应答成功
uint8_t IIC_Wait_Ack(void)
{
u8 ucErrTime=0;
IIC_SDA_IN();
IIC_SDA_SET();delay_us(1);
IIC_SCL_SET();delay_us(1);
while(IIC_SDA_READ())
{
ucErrTime++;
if(ucErrTime>250)
{
IIC_Stop();
return 1;
}
}
IIC_SCL_CLR();//时钟输出0
return 0;
}
//产生ACK应答
void IIC_Ack(void)
{
IIC_SCL_CLR();
IIC_SDA_OUT();
IIC_SDA_CLR();
delay_us(2);
IIC_SCL_SET();
delay_us(2);
IIC_SCL_CLR();
}
//不产生ACK应答
void IIC_NAck(void)
{
IIC_SCL_CLR();
IIC_SDA_OUT();
IIC_SDA_SET();
delay_us(2);
IIC_SCL_SET();
delay_us(2);
IIC_SCL_CLR();
}
//IIC发送一个字节
//返回从机有无应答
//1，有应答
//0，无应答
void IIC_Send_Byte(uint8_t txd)
{
uint8_t t;
IIC_SDA_OUT();
IIC_SCL_CLR();//拉低时钟开始数据传输
for(t=0;t<8;t++)
{
//IIC_SDA=(txd&0x80)>>7;
if(txd&0x80)
IIC_SDA_SET();
else
IIC_SDA_CLR();
txd<<=1;
delay_us(2); //对TEA5767这三个延时都是必须的
IIC_SCL_SET();
delay_us(2);
IIC_SCL_CLR();
delay_us(2);
}
}
//读1个字节，ack=1时，发送ACK，ack=0，发送nACK
uint8_t IIC_Read_Byte(uint8_t ack)
{
uint8_t i,receive=0;
IIC_SDA_IN();//SDA设置为输入
for(i=0;i<8;i++ )
{
IIC_SCL_CLR();
delay_us(2);
IIC_SCL_SET();
receive<<=1;
if(IIC_SDA_READ())receive++;
delay_us(1);
}
if(ack)
IIC_Ack();//发送nACK
else
IIC_NAck();
return receive;
}
//在AT24CXX指定地址读出一个数据
//ReadAddr:开始读数的地址
//返回值 :读到的数据
uint8_t IIC_ReadOneByte(uint16_t ReadAddr)
{
uint8_t temp=0;
IIC_Start();
IIC_Send_Byte(0XA0); //发送写命令
IIC_Wait_Ack();
IIC_Send_Byte(ReadAddr>>8);//发送高地址
IIC_Wait_Ack();
IIC_Send_Byte(ReadAddr&0xff); //发送低地址
IIC_Wait_Ack();
IIC_Start();
IIC_Send_Byte(0XA1); //进入接收模式
IIC_Wait_Ack();
temp=IIC_Read_Byte(0);
IIC_Stop();//产生一个停止条件
return temp;
}
//在AT24CXX指定地址写入一个数据
//WriteAddr :写入数据的目的地址
//DataToWrite:要写入的数据
void IIC_WriteOneByte(uint16_t WriteAddr,uint8_t DataToWrite)
{
IIC_Start();
IIC_Send_Byte(0XA0); //发送写命令
IIC_Wait_Ack();
IIC_Send_Byte(WriteAddr>>8);//发送高地址
IIC_Wait_Ack();
IIC_Send_Byte(WriteAddr&0xff); //发送低地址
IIC_Wait_Ack();
IIC_Send_Byte(DataToWrite); //发送字节
IIC_Wait_Ack();
IIC_Stop();//产生一个停止条件
//OSTimeDly(5);
}
void IIC_WriteBuffer(uint8_t* pBuffer, uint16_t WriteAddr, uint16_t NumByteToWrite)
{
IIC_Start();
IIC_Send_Byte(0XA0); //发送写命令
IIC_Wait_Ack();
IIC_Send_Byte(WriteAddr>>8);//发送高地址
IIC_Wait_Ack();
IIC_Send_Byte(WriteAddr&0xff); //发送低地址
IIC_Wait_Ack();
while(NumByteToWrite--)
{
IIC_Send_Byte(*pBuffer++); //发送字节
IIC_Wait_Ack();
}
IIC_Stop();//产生一个停止条件
}
void IIC_ReadBuffer(uint8_t* pBuffer, uint16_t ReadAddr, uint16_t NumByteToRead)
{
IIC_Start();
IIC_Send_Byte(0XA0); //发送写命令
IIC_Wait_Ack();
IIC_Send_Byte(ReadAddr>>8);//发送高地址
IIC_Wait_Ack();
IIC_Send_Byte(ReadAddr&0xff); //发送低地址
IIC_Wait_Ack();
IIC_Start();
IIC_Send_Byte(0XA1); //进入接收模式
while(NumByteToRead--)
{
IIC_Wait_Ack();
if(NumByteToRead == 1)
*pBuffer++ =IIC_Read_Byte(0);
else
*pBuffer++ =IIC_Read_Byte(1);
}
IIC_NAck();//发送nACK
IIC_Stop();//产生一个停止条件
}
/*********************************************************************************************************
END FILE
*********************************************************************************************************/ |
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