fm.c

单片机C51驱动FM调频收音机模块程序,很不错,值得下载.

#include <reg52.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "uart.h"
#include "I2C.h"

sbit s1=P3^4;                    //手动减小键
sbit s2=P3^5;                    //手动增加键
sbit s3=P3^6;                    //自动减小键
sbit s4=P3^7;                    //自动增加键

#define max_freq 108000
#define min_freq 87500

unsigned int max_pll=0x339b;           //108MHz时的pll,
unsigned int min_pll=0x299d;           //87.5MHz时的pll.

unsigned char radio_write_data[5]={0x2a,0xb6,0x40,0x11,0x40};        //要写入TEA5767的数据
unsigned char radio_read_data[5];        //TEA5767读出的状态

unsigned long frequency;
unsigned int pll;

void delay_ms(unsigned int i)           //us延时函数
{
  unsigned int j,k;
  for(j=i;j>0;j--)
    for(k=125;k>0;k--);
}	

void radio_write(void)
{
    unsigned char i;
    iic_start();
    iic_write8bit(0xc0);        //TEA5767写地址
    if(!iic_testack())
    {
        for(i=0;i<5;i++)
        {
            iic_write8bit(radio_write_data[i]);
            iic_ack();
        }
    }
    iic_stop();    
}

//由频率计算PLL
void get_pll(void)
{
    unsigned char hlsi;
    unsigned int twpll=0;
    hlsi=radio_write_data[2]&0x10;
    if (hlsi)
        pll=(unsigned int)((float)((frequency+225)*4)/(float)32.768);    //频率单位:k
    else
        pll=(unsigned int)((float)((frequency-225)*4)/(float)32.768);    //频率单位:k
}


//由PLL计算频率
void get_frequency(void)
{
    unsigned char hlsi;
    unsigned int npll=0;
    npll=pll;
    hlsi=radio_write_data[2]&0x10;
    if (hlsi)
        frequency=(unsigned long)((float)(npll)*(float)8.192-225);    //频率单位:KHz
    else
        frequency=(unsigned long)((float)(npll)*(float)8.192+225);    //频率单位:KHz
}

//读TEA5767状态,并转换成频率
void radio_read(void)
{
    unsigned char i;
    unsigned char temp_l,temp_h;
    pll=0;
    iic_start();
    iic_write8bit(0xc1);        //TEA5767读地址
    if(!iic_testack())
    {
        for(i=0;i<5;i++)
        {
            radio_read_data[i]=iic_read8bit();
            iic_ack();
        }
    }
    iic_stop();
    temp_l=radio_read_data[1];
    temp_h=radio_read_data[0];
    temp_h&=0x3f;
    pll=temp_h*256+temp_l;
    get_frequency();
}



//手动设置频率,mode=1,+0.01MHz; mode=0:-0.01MHz ,不用考虑TEA5767用于搜台的相关位:SM,SUD
void search(bit mode)
{
    radio_read();        
    if(mode)
    {
        frequency+=10;
        if(frequency>max_freq)
            frequency=min_freq;
    }
    else
    {
        frequency-=10;
        if(frequency<min_freq)
            frequency=max_freq;
    }          
    get_pll();
    radio_write_data[0]=pll/256;
    radio_write_data[1]=pll%256;
    radio_write_data[2]=0x41;
    radio_write_data[3]=0x11;
    radio_write_data[4]=0x40;
    radio_write();
}

//自动搜台,mode=1,频率增加搜台; mode=0:频率减小搜台,不过这个好像不能循环搜台
void auto_search(bit mode)
{
    radio_read();        
    if(mode)
    {
        radio_write_data[2]=0xb1;
        frequency+=20;
        if(frequency>max_freq)
            frequency=min_freq;
    }
    else
    {
		radio_write_data[2]=0x41; 
        frequency-=20;
        if(frequency<min_freq)
            frequency=max_freq;
    }          
    get_pll();

    radio_write_data[0]=pll/256+0x40;      //加0x40是将SM置为1 为自动搜索模式
    radio_write_data[1]=pll%256;    
    radio_write_data[3]=0x11;              //SSL1和SSL0控制搜索停止条件             
    radio_write_data[4]=0x40;
    radio_write();
    radio_read();
    while(!(radio_read_data[0]&0x80))     //搜台成功标志
    {
        radio_read();
    }    
} 


void main()
{
 P3=0xff;
 UART_Init(); 
 comm("WWW.TXMCU.COM \r\n\0");
 comm("HELLO FM \r\n\0");

 radio_write(); 

 while(1)
 {

 
  if(s1==0) 
  {delay_ms(1);
   if(s1==0)
   {
     while(s1==0);
     search(0);  send_fre(frequency);
   }
  }

  if(s2==0) 
  {delay_ms(1);
   if(s2==0)
   { 
	 while(s2==0);
     search(1);  send_fre(frequency);
   }
  }

  if(s3==0) 
  {delay_ms(1);
   if(s3==0)
   {
     auto_search(0);  send_fre(frequency);
   }
  }

  if(s4==0) 
  {delay_ms(1);
   if(s4==0)
   {
     auto_search(1);  send_fre(frequency);
   }
  }

 } 
}