You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
146 lines
2.7 KiB
146 lines
2.7 KiB
#include "mpuiic.h"
|
|
#include "delay.h"
|
|
|
|
//MPU IIC 延时函数
|
|
void MPU_IIC_Delay(void)
|
|
{
|
|
delay_us(2);
|
|
}
|
|
|
|
//初始化IIC
|
|
void MPU_IIC_Init(void)
|
|
{
|
|
GPIO_InitTypeDef GPIO_InitStructure;
|
|
|
|
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC,ENABLE);//先使能外设IO PORTC时钟
|
|
|
|
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12|GPIO_Pin_11; // 端口配置
|
|
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; //推挽输出
|
|
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //IO口速度为50MHz
|
|
GPIO_Init(GPIOC, &GPIO_InitStructure); //根据设定参数初始化GPIO
|
|
|
|
GPIO_SetBits(GPIOC,GPIO_Pin_12|GPIO_Pin_11); //PB10,PB11 输出高
|
|
|
|
}
|
|
//产生IIC起始信号
|
|
void MPU_IIC_Start(void)
|
|
{
|
|
MPU_SDA_OUT(); //sda线输出
|
|
MPU_IIC_SDA=1;
|
|
MPU_IIC_SCL=1;
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SDA=0;//START:when CLK is high,DATA change form high to low
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=0;//钳住I2C总线，准备发送或接收数据
|
|
}
|
|
//产生IIC停止信号
|
|
void MPU_IIC_Stop(void)
|
|
{
|
|
MPU_SDA_OUT();//sda线输出
|
|
MPU_IIC_SCL=0;
|
|
MPU_IIC_SDA=0;//STOP:when CLK is high DATA change form low to high
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=1;
|
|
MPU_IIC_SDA=1;//发送I2C总线结束信号
|
|
MPU_IIC_Delay();
|
|
}
|
|
//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
|
|
u8 MPU_IIC_Wait_Ack(void)
|
|
{
|
|
u8 ucErrTime=0;
|
|
MPU_SDA_IN(); //SDA设置为输入
|
|
MPU_IIC_SDA=1;MPU_IIC_Delay();
|
|
MPU_IIC_SCL=1;MPU_IIC_Delay();
|
|
while(MPU_READ_SDA)
|
|
{
|
|
ucErrTime++;
|
|
if(ucErrTime>250)
|
|
{
|
|
MPU_IIC_Stop();
|
|
return 1;
|
|
}
|
|
}
|
|
MPU_IIC_SCL=0;//时钟输出0
|
|
return 0;
|
|
}
|
|
//产生ACK应答
|
|
void MPU_IIC_Ack(void)
|
|
{
|
|
MPU_IIC_SCL=0;
|
|
MPU_SDA_OUT();
|
|
MPU_IIC_SDA=0;
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=1;
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=0;
|
|
}
|
|
//不产生ACK应答
|
|
void MPU_IIC_NAck(void)
|
|
{
|
|
MPU_IIC_SCL=0;
|
|
MPU_SDA_OUT();
|
|
MPU_IIC_SDA=1;
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=1;
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=0;
|
|
}
|
|
//IIC发送一个字节
|
|
//返回从机有无应答
|
|
//1，有应答
|
|
//0，无应答
|
|
void MPU_IIC_Send_Byte(u8 txd)
|
|
{
|
|
u8 t;
|
|
MPU_SDA_OUT();
|
|
MPU_IIC_SCL=0;//拉低时钟开始数据传输
|
|
for(t=0;t<8;t++)
|
|
{
|
|
MPU_IIC_SDA=(txd&0x80)>>7;
|
|
txd<<=1;
|
|
MPU_IIC_SCL=1;
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=0;
|
|
MPU_IIC_Delay();
|
|
}
|
|
}
|
|
//读1个字节，ack=1时，发送ACK，ack=0，发送nACK
|
|
u8 MPU_IIC_Read_Byte(unsigned char ack)
|
|
{
|
|
unsigned char i,receive=0;
|
|
MPU_SDA_IN();//SDA设置为输入
|
|
for(i=0;i<8;i++ )
|
|
{
|
|
MPU_IIC_SCL=0;
|
|
MPU_IIC_Delay();
|
|
MPU_IIC_SCL=1;
|
|
receive<<=1;
|
|
if(MPU_READ_SDA)receive++;
|
|
MPU_IIC_Delay();
|
|
}
|
|
if (!ack)
|
|
MPU_IIC_NAck();//发送nACK
|
|
else
|
|
MPU_IIC_Ack(); //发送ACK
|
|
return receive;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|