#include "delay.h"
#include "GY30/BH1750FVI.h"
typedef unsigned char BYTE;
//BYTE BUF[8]; //接收数据缓存区
//iic接口初始化
/**
** 设置SDA为输出
**/
void BH1750_SDA_OUT(void)
{
GPIO_InitTypeDef GPIO_InitStructer;
GPIO_InitStructer.GPIO_Pin= BH1750_SDA_GPIO_PIN;
GPIO_InitStructer.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_InitStructer.GPIO_Mode=GPIO_Mode_Out_PP;
GPIO_Init(BH1750_GPIO_PORT, &GPIO_InitStructer);
}
/**
** 设置SDA为输入
**/
void BH1750_SDA_IN(void)
{
GPIO_InitTypeDef GPIO_InitStructer;
GPIO_InitStructer.GPIO_Pin= BH1750_SDA_GPIO_PIN;
GPIO_InitStructer.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_InitStructer.GPIO_Mode=GPIO_Mode_IPU;
GPIO_Init(BH1750_GPIO_PORT, &GPIO_InitStructer);
}
void Single_Write_BH1750(uchar REG_BH1750_ADDRess)
{
BH1750_IIC_Start(); //起始信号
BH1750_IIC_Send_Byte(BHAddWrite); //发送设备地址+写信号
BH1750_IIC_Send_Byte(REG_BH1750_ADDRess); //内部寄存器地址，
// BH1750_SendByte(REG_data); //内部寄存器数据，
BH1750_IIC_Stop(); //发送停止信号
}
void BH1750_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(BH1750_GPIO_CLK, ENABLE); //使能A端口时钟
GPIO_InitStructure.GPIO_Pin = BH1750_SCL_GPIO_PIN|BH1750_SDA_GPIO_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; //推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;//速度50MHz
GPIO_Init(BH1750_GPIO_PORT, &GPIO_InitStructure); //初始化GPIOD3,6
GPIO_SetBits(BH1750_GPIO_PORT,BH1750_SCL_GPIO_PIN|BH1750_SDA_GPIO_PIN);
Single_Write_BH1750(0x01);
bh_data_send(BHPowOn);
bh_data_send(BHReset);
bh_data_send(BHModeH2); //选择的是分辨率是4lx，测量时间是16ms的
}
//产生IIC起始信号
void BH1750_IIC_Start(void)
{
BH1750_SDA_OUT(); //sda线输出
BH1750_IIC_SDA=1;
BH1750_IIC_SCL=1;
delay_us(4);
BH1750_IIC_SDA=0;//START:when CLK is high,DATA change form high to low
delay_us(4);
BH1750_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 BH1750_IIC_Stop(void)
{
BH1750_SDA_OUT();//sda线输出
BH1750_IIC_SCL=0;
BH1750_IIC_SDA=0;//STOP:when CLK is high DATA change form low to high
delay_us(4);
BH1750_IIC_SCL=1;
BH1750_IIC_SDA=1;//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
u8 BH1750_IIC_Wait_Ack(void)
{
u8 ucErrTime=0;
BH1750_SDA_IN(); //SDA设置为输入
BH1750_IIC_SDA=1;delay_us(1);
BH1750_IIC_SCL=1;delay_us(1);
while(BH1750_READ_SDA)
{
ucErrTime++;
if(ucErrTime>250)
{
BH1750_IIC_Stop();
return 1;
}
}
BH1750_IIC_SCL=0;//时钟输出0
return 0;
}
//产生ACK应答
void BH1750_IIC_Ack(void)
{
BH1750_IIC_SCL=0;
BH1750_SDA_OUT();
BH1750_IIC_SDA=0;
delay_us(2);
BH1750_IIC_SCL=1;
delay_us(2);
BH1750_IIC_SCL=0;
}
//不产生ACK应答
void BH1750_IIC_NAck(void)
{
BH1750_IIC_SCL=0;
BH1750_SDA_OUT();
BH1750_IIC_SDA=1;
delay_us(2);
BH1750_IIC_SCL=1;
delay_us(2);
BH1750_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 BH1750_IIC_Send_Byte(u8 txd)
{
u8 t;
BH1750_SDA_OUT();
BH1750_IIC_SCL=0;//拉低时钟开始数据传输
for(t=0;t<8;t++)
{
//BH1750_IIC_SDA=(txd&0x80)>>7;
if((txd&0x80)>>7)
BH1750_IIC_SDA=1;
else
BH1750_IIC_SDA=0;
txd<<=1;
delay_us(2); //对TEA5767这三个延时都是必须的
BH1750_IIC_SCL=1;
delay_us(2);
BH1750_IIC_SCL=0;
delay_us(2);
}
}
//读1个字节，ack=1时，发送ACK，ack=0，发送nACK
u8 BH1750_IIC_Read_Byte(unsigned char ack)
{
unsigned char i,receive=0;
BH1750_SDA_IN();//SDA设置为输入
for(i=0;i<8;i++ )
{
BH1750_IIC_SCL=0;
delay_us(2);
BH1750_IIC_SCL=1;
receive<<=1;
if(BH1750_READ_SDA)receive++;
delay_us(1);
}
if (!ack)
BH1750_IIC_NAck();//发送nACK
else
BH1750_IIC_Ack(); //发送ACK
return receive;
}
/*************************************************************************************/
void bh_data_send(u8 command)
{
do{
BH1750_IIC_Start(); //iic起始信号
BH1750_IIC_Send_Byte(BHAddWrite); //发送器件地址
}while(BH1750_IIC_Wait_Ack()); //等待从机应答
BH1750_IIC_Send_Byte(command); //发送指令
BH1750_IIC_Wait_Ack(); //等待从机应答
BH1750_IIC_Stop(); //iic停止信号
}
u16 bh_data_read(void)
{
u16 buf;
BH1750_IIC_Start(); //iic起始信号
BH1750_IIC_Send_Byte(BHAddRead); //发送器件地址+读标志位
BH1750_IIC_Wait_Ack(); //等待从机应答
buf=BH1750_IIC_Read_Byte(1); //读取数据
buf=buf<<8; //读取并保存高八位数据
buf+=0x00ff&BH1750_IIC_Read_Byte(0); //读取并保存第八位数据
BH1750_IIC_Stop(); //发送停止信号
return buf;
}
