main.c

SHT71数字温湿度传感器的AVR单片机驱动程序

#include <iom128.h>
#include <macros.h>
#include "sensor.h"

#pragma interrupt_handler USART_RX_interrupt:19		//串口0接收中断

unsigned char MCU_receive_byte(void);
void Sent_command(unsigned char command);
void MCU_receive_word(void);
void Port_ini(void);
void SHT_ACK();
void SHT_end(void);
void SHT_ini(void);
void SHT_reset(void);
void SHT_start();
void SHT_measurement(unsigned char measure);
void USART_RX_interrupt(void);
void USART_TX(unsigned char data);
void USART_ini(void);
void WDT_ini(void);

//
//------------------------------
//
//		主函数
//		
//------------------------------
//	
void main(void)
{    
	 unsigned int i;
	 
	 //WDT_ini();
	 CLI();
     
	 Port_ini();
	 SHT_ini();
	 USART_ini();

	 SEI();

	 //---for test----
	 USART_TX(0xaa);

	 //---------------
	 for(;;)
	 {	
	    //WDR();				//看门狗清零
      	SHT_measurement(TEMPERATURE);
		for(i=0;i<65535;i++)
		{
		}
	 }
	 
}

//
//------------------------------
//
//		串口0单字节发送
//
//------------------------------
//

void USART_TX(unsigned char data)
{
 	while(!(UCSR0A&(1<<UDRE0)))
	{
	}
   	UDR0 = data;
}

//
//------------------------------
//
//		串口初始化
//
//------------------------------
//
void USART_ini(void)
{
    UBRR0H = 0x00;
	UBRR0L = 0xCF;       //波特率2400
	UCSR0C = 0x06;      //异步模式，无奇偶校验，一个停止位，8位数据
	UCSR0B = 0x80|(1<<RXEN0)|(1<<TXEN0);       //发送、接收使能
}

//
//------------------------------
//
//		SHT71启动信号
//
//------------------------------
//
void SHT_start()
{	 
	 DDRD = DDRD|0x03; //?????
	 PORTD =  CLK_L ;
	 PORTD = DATA_H;
   	 NOP();
	 NOP();
	 PORTD =  CLK_H;
	 NOP();
	 NOP();
	 PORTD = DATA_L;
	 NOP();
	 NOP();
	 PORTD =  CLK_L;
	 NOP();
	 NOP();
	 PORTD =  CLK_H;
	 NOP();
	 NOP();
	 PORTD = DATA_H;
	 NOP();
	 NOP();
	 PORTD =  CLK_L;
}
//
//------------------------------
//
//		SHT71 控制命令发送
//		command =	0x03---温度
//					0x05---湿度
//
//------------------------------
//	
void Sent_command(unsigned char command)
{
	unsigned char model = 0x80;
	unsigned char i;   
	
	DDRD = DDRD|0x03;                    //输出
	//PORTD =  CLK_L;
	for(i=0;i<7;i++)           
	{
		PORTD =  CLK_L;
		if((command & model) == 0)
		{
			PORTD = DATA_L;
		}
		else
		{
			PORTD = DATA_H;
		}
			
		PORTD =  CLK_H;
		//NOP();
		model = model>>1;
		//PORTD =  CLK_L;
		  
	} 
	
	PORTD = CLK_L;
	
	if((command & model) == 0)
	{
		PORTD = DATA_L;
	}
	else
	{
		PORTD = DATA_H;
	}
	
	//PORTD = DATA_L;
	// NOP();
	PORTD =  CLK_H; 
	DDRD = DDRD&0xFD;
	NOP();
	PORTD = CLK_L;		 
	
	while((PIND&0x02)==0x02)
	{
	}
			//PORTD = 0x55;
	PORTD =  CLK_H;
	NOP();
	PORTD =  CLK_L;
	NOP();	
}	
//
//------------------------------
//
//		SHT71 等待应答信号
//
//------------------------------
//	
void SHT_ACK()
{	
	//PORTA = ~(0xFF);
	while((PIND&0x02)==0x02)
	{
	}
	//PORTA = 0x55;
}
//
//------------------------------
//
//		SHT71 接收一个字节
//		
//------------------------------
//	
unsigned char MCU_receive_byte(void)
{	 
	unsigned char i;
	unsigned char model = 0x00;
	unsigned char temp;
	      
	PORTD =  CLK_L;
	NOP();
	for(i=0;i<8;i++)
	{
		PORTD =  CLK_H;
		//PORTD =  CLK_L; 
		if((PIND & 0x02)==0)
		{
			temp = 0;
		}
		else
		{
			temp = 1;
		}
		
		model = model|(temp<<(7-i));
		
		PORTD =  CLK_L;
	 }

	 DDRD = DDRD|0x02;  //单片机输出ACK
	 //PORTD =  CLK_L;

	 PORTD = DATA_L;    //
	 NOP();
	 PORTD =  CLK_H; 
	 DDRD = DDRD&0xFD;  //单片机输入
	 PORTD =  CLK_L; 
	 return model;
}
//
//------------------------------
//
//		SHT71 接收结果
//		
//------------------------------
//	
void MCU_receive_word(void)
{ 
      unsigned char temp;
	  temp = MCU_receive_byte();
	  //PORTA = ~temp;
	  temp = MCU_receive_byte();
	  //PORTC = ~temp;
}
//
//------------------------------
//
//		SHT71 启动一次测量
//		
//------------------------------
//	
void SHT_measurement(unsigned char measure)
{
 	 //DDRD = DDRD|0x03; //?????
	 SHT_start();
	 Sent_command(measure); 
	 SHT_ACK();
	 MCU_receive_word();
	 SHT_end();
} 
//
//------------------------------
//
//		SHT71 结束一次测量
//		
//------------------------------
//	
void SHT_end(void)
{
 	 PORTD =  CLK_L;
	 PORTD = DATA_H;
}
//
//------------------------------
//
//		SHT71 复位
//		
//------------------------------
//	
void SHT_reset(void)
{
	unsigned char i;
	
	//DDRD = DDRD|0x03;
	
	PORTD = DATA_H;
	PORTD = CLK_L;
	
	for (i=0;i<20 ;i++ )
	{
		PORTD =  CLK_H;
		NOP();
		PORTD =  CLK_L;
	}

}
//
//------------------------------
//
//		看门狗初始化
//		
//------------------------------
//	
void WDT_ini(void)
{
	WDTCR = 0x0f;
}
//
//------------------------------
//
//		SHT71初始化
//		
//------------------------------
//	
void SHT_ini(void)
{	 
	unsigned int i;
	SHT_reset();
	for(i=0;i<65535;i++)
	{
	}
}
//
//------------------------------
//
//		端口初始化
//		
//------------------------------
//	
void Port_ini(void)
{
	DDRA = 0xFF;
	DDRC = 0xFF;
	DDRD = DDRD|0x03; //?????
}
//
//------------------------------
//
//		串口接收中断初始化
//		
//------------------------------
//	
void USART_RX_interrupt(void)
{
    unsigned char i;
    
	i= UDR0;
	//USART_TX(i);
	//PORTA = i;
	/*if (i==0x08)
	{
		USART_TX(0x99);
	}
	*/
}