dac084x.c

基于ATMEL的ATMEGA8单片机对max0842--AD转换芯片的DRIVER编程。

/***********************************************
****       AVR  SPI接口使用范例   	          ***
****  	                                      ***
**** 作者：                                   ***
**** 编译器：WINAVR20050214                   ***
****外部晶振 4MHz,F_CPU=4000000               ***
***********************************************/
#include <avr/io.h>
#include "main.h"

void delay_us(uchar t)
{
  uchar time;
  for(time=0;time<t;time++);	   
}


/*-----------------------------------------------------------------------
Single_SPI    : 使用SPI接口写数据到device
 
输入参数：	command:	命令选择;
返回值		rdata:		读回的数据;	
   (SPI的收发是同时进行的)
-----------------------------------------------------------------------*/
void Single_SPI(uchar command,uchar DAC_Data)
{
    uchar i;
	uint temp;
	temp=(command<<8)|(DAC_Data<<4);
	//I/O direction must be set correct first!
	//then init I/O below:
    
	SCK_RESET;//
	
	SYNC_RESET;
    delay_us(2);
	SYNC_SET;
    delay_us(2);
	SYNC_RESET;

	for(i=0;i<16;i++){//传送命令到 DEVICE
	  if(temp&0x8000) DATA_SET;
	  else DATA_RESET;
	  
	  SCK_SET;
	  delay_us(2);
	  SCK_RESET;  //
	  delay_us(2);
	  
	  temp<<=1;
	}	
	
    SYNC_SET;
}



void DecodeBCD(unsigned int temp)
{
  uchar i,num_bit[3];

  for(i=0;i<3;i++)
  {
   num_bit[2-i]=temp%10;
   temp=temp/10;
  }
  
  /**********将转换结果发送到串行口***********/
  putchar(48+num_bit[0]);   	
  putchar(48+num_bit[1]);	
  putchar(48+num_bit[2]);	 	 

}

void Display_Voltage(uchar data)
{
  float voltage;
  uchar int_digit;  
  voltage=(3.264*data)/255;
  int_digit=(uchar)voltage;
  voltage-=int_digit;
  //
  DecodeBCD(int_digit);
  putchar('.'); 
  DecodeBCD(voltage*1000);
  
}

void Read_and_Disp(void)
{
	putchar(0x0d); putchar(0x0a);//回车换行
		  
	Single_SPI((DAC_Channel<<6)|(DAC_Cmd<<4),DAC_Result);//
	putchar(0x0d); putchar(0x0a);//回车换行
    if(DAC_Cmd==00){
		puts("The command only Write data to DAC channel:"); DecodeBCD(DAC_Channel);	
		putchar(0x0d); putchar(0x0a);//回车换行  
		puts("The Digital to Convert Is:"); DecodeBCD(DAC_Result);
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The Convert Result Is:"); Display_Voltage(DAC_Result);
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("But do not covert and update outputs!"); 
		putchar(0x0d); putchar(0x0a);//回车换行
	}
    else if(DAC_Cmd==01){
		puts("This is a single channel Convert command!");  	  
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The command to Convert Is:"); DecodeBCD(DAC_Cmd);	  
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The channel to Convert Is:"); DecodeBCD(DAC_Channel);	  
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The Digital to Convert Is:"); DecodeBCD(DAC_Result);
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The Convert Result Is:"); Display_Voltage(DAC_Result);
		putchar(0x0d); putchar(0x0a);//回车换行
	}
    else if(DAC_Cmd==02){
		puts("This is a all channel Convert command!");  	  
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The command to Convert Is:"); DecodeBCD(DAC_Cmd);	  
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The channel to Convert Is: DAC A, DAC B, DAC C, DAC D"); 	  

		puts("The Digital to Convert Is:"); DecodeBCD(DAC_Result);
		putchar(0x0d); putchar(0x0a);//回车换行
		puts("The Convert Result Is:"); Display_Voltage(DAC_Result);
		putchar(0x0d); putchar(0x0a);//回车换行
	}
	else{
		puts("This is Device Power down Command!"); 
	}
	
	puts("You Can check Right or Error!");
	putchar(0x0d); putchar(0x0a);//回车换行
}

int main(void)
{
    char cmd;
    DAC_Result=0x0; //初始转换值
	DAC_Channel=0x0;//初始通道
	DAC_Cmd=0x01;    //命令模式

    //上电默认DDRx=0x00,PORTx=0x00 输入，无上拉电阻
    //PORTA=0xFF;	//不用的管脚使能内部上拉电阻
    PORTC=0xFF;
    PORTD=0xFF;
    DDRD=(1<<PIN_TXD);	//串口的输出
    PORTB=~((1<<SPI_MOSI)|(1<<SPI_SCK)|(1<<SYNC)); //						
    DDRB = (1<<SYNC)|(1<<SPI_SCK)|(1<<SPI_MOSI);   //设定SPI接口
    									
    init_USART();


    puts("Pls Input Char!");
    puts("Input Char 'a' to Change Digital to Convert!");
	puts("Input Char 'b' to Change Channel to Convert!");
	puts("Input Char 'c' to Change Command to Convert!");
	puts("Input Any Other Char to keep Now Status!");
	
    while(1)
	{
	  cmd=getchar();
	  if(cmd=='a'){//转换值递增
        DAC_Result+=15;
		if(DAC_Result>255) DAC_Result=0;
        Read_and_Disp();
	  }
	  else if(cmd=='b'){//转换通道后，其他通道的输出维持原转换值不变！ 
	    DAC_Channel++;
		if(DAC_Channel>3) DAC_Channel=0;//DAC A ~ DAC D
	    Read_and_Disp();
	  }
	  else if(cmd=='c'){//切换转换命令方式 
	    DAC_Cmd++;
		if(DAC_Cmd>3) DAC_Cmd=0;//cmd:00 01 10 and 11 --->four mode
	    Read_and_Disp();
	  }
	  else{//接受到其他任意字符
        Read_and_Disp(); 
	  }
	  
	}
	
    return 1;
}