//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;
}
//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();
}
void MPU_I2C_stop()
{
MPU_SDA_OUT();
MPU_I2C_SDA_W = 0;
MPU_I2C_DELAY();
MPU_I2C_SCL = 1;
MPU_I2C_DELAY();
MPU_I2C_SDA_W = 1;
delayMs(10);
}
void MPU_I2C_start()
{
MPU_SDA_OUT();
MPU_I2C_SDA_W = 1;
MPU_I2C_DELAY();
MPU_I2C_SCL = 1;
MPU_I2C_DELAY();
MPU_I2C_SDA_W = 0;
MPU_I2C_DELAY();
//MPU_I2C_SCL = 0;//拉低SCL,等待发送或接收数据
}
void MPU_I2C_respond(u8 ack)//应答信号:在第9个时钟周期SCL为高时,SDA为低
{
MPU_SDA_OUT();
MPU_I2C_SCL = 0;//拉低SCL,等待发送或接收数据
MPU_I2C_DELAY();
MPU_I2C_SDA_W = 1 - ack;
MPU_I2C_DELAY();
MPU_I2C_SCL = 1;
MPU_I2C_DELAY();
MPU_I2C_SCL = 0;
MPU_I2C_DELAY();
}
//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();
}
}
void MPU_I2C_sendByte(u8 txd)
{
u8 i;
MPU_SDA_OUT();
MPU_I2C_SCL = 0;//拉低SCL,等待发送数据
MPU_I2C_DELAY();
for(i = 0;i < 8;i ++)
{
MPU_I2C_SDA_W = (txd & 0x80) >> 7;
txd <<= 1;
MPU_I2C_DELAY();
MPU_I2C_SCL = 1;
MPU_I2C_DELAY();
MPU_I2C_SCL = 0;
MPU_I2C_DELAY();
}
}
