//DHT11初始化 
//返回0：初始化成功，1：失败
u8 DHT11_Init()
{
	GPIO_InitTypeDef GPIO_InitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOG,ENABLE);

	GPIO_InitStructure.GPIO_Pin=DHT11;
	GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;
	GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
	GPIO_Init(GPIO_DHT11,&GPIO_InitStructure);
	GPIO_SetBits(GPIO_DHT11,DHT11);	   //拉高

	DHT11_Rst();	  
	return DHT11_Check();	
}

//复位DHT11
void DHT11_Rst()	   
{                 
	DHT11_IO_OUT(); 	//SET OUTPUT
    DHT11_DQ_OUT=0; 	//拉低DQ
    delay_ms(20);    	//拉低至少18ms
    DHT11_DQ_OUT=1; 	//DQ=1 
	delay_us(30);     	//主机拉高20~40us
}
//等待DHT11的回应
//返回1:未检测到DHT11的存在
//返回0:存在
u8 DHT11_Check() 	   
{   
	u8 retry=0;
	DHT11_IO_IN();//SET INPUT	 
    while (DHT11_DQ_IN&&retry<100)//DHT11会拉低40~50us
	{
		retry++;
		delay_us(1);
	};	 
	if(retry>=100)return 1;
	else retry=0;
    while (!DHT11_DQ_IN&&retry<100)//DHT11拉低后会再次拉高40~50us
	{
		retry++;
		delay_us(1);
	};
	if(retry>=100)return 1;	    
	return 0;
}

//从DHT11读取一个位
//返回值：1/0
u8 DHT11_Read_Bit(void) 			 
{
 	u8 retry=0;
	while(DHT11_DQ_IN&&retry<100)//等待变为低电平 12-14us 开始
	{
		retry++;
		delay_us(1);
	}
	retry=0;
	while(!DHT11_DQ_IN&&retry<100)//等待变高电平	 26-28us表示0,116-118us表示1
	{
		retry++;
		delay_us(1);
	}
	delay_us(40);//等待40us
	if(DHT11_DQ_IN)return 1;
	else return 0;		   
}

//从DHT11读取一个字节
//返回值：读到的数据
u8 DHT11_Read_Byte(void)    
{        
    u8 i,dat;
    dat=0;
	for (i=0;i<8;i++) 
	{
   		dat<<=1; 
	    dat|=DHT11_Read_Bit();
    }						    
    return dat;
}

//初始化光敏传感器
void Lsens_Init(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	ADC_InitTypeDef ADC_InitStructure; 
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOF,ENABLE);//使能PORTF时钟	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE );	  //使能ADC3通道时钟
	RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC3, ENABLE);//ADC复位	
	RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC3, DISABLE);//复位结束
	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;//PF8 anolog输入
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;		//模拟输入引脚
	GPIO_Init(GPIOF, &GPIO_InitStructure);	
	
	ADC_DeInit(ADC3);  //复位ADC3,将外设 ADC3的全部寄存器重设为缺省值

	ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;	//ADC工作模式: 独立模式
	ADC_InitStructure.ADC_ScanConvMode = DISABLE;	//模数转换工作在单通道模式
	ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;	//模数转换工作在单次转换模式
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;	//转换由软件而不是外部触发启动
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;	//ADC数据右对齐
	ADC_InitStructure.ADC_NbrOfChannel = 1;	//顺序进行规则转换的ADC通道的数目
	ADC_Init(ADC3, &ADC_InitStructure);	//根据ADC_InitStruct中指定的参数初始化外设ADCx的寄存器  

	ADC_Cmd(ADC3, ENABLE);	//使能指定的ADC3
	
	ADC_ResetCalibration(ADC3);	//使能复位校准  
	 
	while(ADC_GetResetCalibrationStatus(ADC3));	//等待复位校准结束
	
	ADC_StartCalibration(ADC3);	 //开启AD校准
 
	while(ADC_GetCalibrationStatus(ADC3));	 //等待校准结束
}

//获得ADC3某个通道的值
//ch:通道值 0~16
//返回值:转换结果
u16 Get_ADC3(u8 ch)   
{
	//设置指定ADC的规则组通道，一个序列，采样时间
	ADC_RegularChannelConfig(ADC3, ch, 1, ADC_SampleTime_239Cycles5 );	//ADC3,ADC通道,采样时间为239.5周期	  			    
  
	ADC_SoftwareStartConvCmd(ADC3, ENABLE);		//使能指定的ADC3的软件转换启动功能	
	 
	while(!ADC_GetFlagStatus(ADC3, ADC_FLAG_EOC ));//等待转换结束

	return ADC_GetConversionValue(ADC3);	//返回最近一次ADC3规则组的转换结果
} 


//读取Light Sens的值
//0~100:0,最暗;100,最亮 
u8 Lsens_Get_Val(void)
{
	u32 temp_val=0;
	u8 t;
	for(t=0;t<LSENS_READ_TIMES;t++)
	{
		temp_val+=Get_ADC3(ADC_Channel_6);	//读取ADC值
		delay_ms(5);
	}
	temp_val/=LSENS_READ_TIMES;//得到平均值 
	if(temp_val>4000)temp_val=4000;
	return (u8)(100-(temp_val/40));
}

void usart2_init( void )
{	
	GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
	RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA, ENABLE ); 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
	GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE);
		 		
  	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; //PA2
  	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//复用推挽输出
  	GPIO_Init(GPIOA, &GPIO_InitStructure);
  	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;//PA3
  	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
  	GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIOA 

   	//USART2 初始化设置
	USART_InitStructure.USART_BaudRate = 115200;//串口波特率
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收发模式
  	USART_Init(USART2, &USART_InitStructure); //初始化串口2

	USART_ClearFlag(USART2, USART_FLAG_TC);
	
  	USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启串口接受和总线空闲中断
  	//USART_ITConfig(USART2, USART_IT_IDLE, ENABLE);
	
	USART_Cmd(USART2, ENABLE);                    //使能串口2 
	
	//USART2 NVIC 配置
  	NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//子优先级3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ通道使能
	NVIC_Init(&NVIC_InitStructure);	//根据指定的参数初始化VIC寄存器
}

//初始化TIM2
void TIM2_init(u16 arr, u16 psc){
	TIM_TimeBaseInitTypeDef TIM_Structure;
	NVIC_InitTypeDef NVIC_Structure;
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	
	//延时时间（单位:s）：arr/(72000000/psc)
	TIM_Structure.TIM_Period = arr - 1;  //装载值
	TIM_Structure.TIM_Prescaler = psc-1;  //分频系数
	TIM_Structure.TIM_ClockDivision = 0;
	TIM_Structure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInit(TIM2, &TIM_Structure);
	
	TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE); //开启定时器TIM2中断
	TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
	NVIC_Structure.NVIC_IRQChannel = TIM2_IRQn;
	NVIC_Structure.NVIC_IRQChannelPreemptionPriority = 6; //抢占优先级
	NVIC_Structure.NVIC_IRQChannelSubPriority = 4;  //子优先级
	NVIC_Structure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_Structure);

	TIM_ClearFlag(TIM2, TIM_FLAG_Update);
	TIM_Cmd(TIM2, ENABLE);
}