#include "stc89c51.h"
#include "iic.h"

sbit scl0=P3^5;
sbit sda0 = P3^4;
sbit scl1= P3^3;
sbit sda1 = P3^2;


unsigned char iic_delay_time = 8;

void scl(device,value);
void sda(device,value);
bit sdasense(char device);

// delay
void iic_delay(unsigned char m)
{
    unsigned char n;
    for(n=0;n<m;n++);
}

//
void scl(device,value) 
{
    if (device==0)        //設備1
        scl1=value;
    if (device==1)        //設備2
        scl2=value;
}
void sda(device,value)
{
    if (device==0)        //設備1
        sda1=value;
    if (device==1)        //設備2
        sda2=value;
}

bit sdasense(char device)
{
switch(device)
    {
        case 1: return sda1;
            break;
        case 2: return sda2;
            break;
    }
}

//啟動I2C總線的函數，當scl為高電平時使sda產生一個負跳變 
void iic_start(device) 
{
    sda(device,1);
    scl(device,1);
    iic_delay(iic_delay_time);
    sda(device,0);
    iic_delay(iic_delay_time);
    scl(device,0);
    iic_delay(iic_delay_time/2);
}

//終止I2C總線，當scl為高電平時使sda產生一個正跳變
void iic_stop(device) 
{
    scl(device,0);
    sda(device,0);
    scl(device,1);
    iic_delay(iic_delay_time);
    sda(device,1);
    iic_delay(iic_delay_time);
}

//發送應答信號
void iic_ack(device) {
    sda(device,0);
    scl(device,1);
    scl(device,0);
    sda(device,1);
}

//發送無應答信號
void iic_noack(device) 
{
    sda(device,1);
    scl(device,1);
    scl(device,0);
} 

//檢測應答信號
bit iic_testack(device) 
{
    bit errorbit;      //真確應答,返回0
    sda(device,1);
    iic_delay(iic_delay_time);
    scl(device,1);
    iic_delay(iic_delay_time);
    errorbit=sdasense(device);
    scl(device,0);
    iic_delay(iic_delay_time);
    return(errorbit);
}

//發送一個字節
void iic_write8bit(device,unsigned char input) 
{
    unsigned char temp;
    for(temp=0;temp<8;temp++) 
    {
        if((input<<temp)&0x80)
            sda(device,1);
        else
            sda(device,0);
        scl(device,1);

        iic_delay(iic_delay_time);
        scl(device,0);
    }
}

//讀一個字節
unsigned char iic_read8bit(device) 
{
    unsigned char temp,rbyte=0;
    for(temp=0;temp<8;temp++) 
    {
        scl(device,1);
        iic_delay(iic_delay_time);
        if(sdasense(device))
            rbyte=(rbyte<<1)+1;
        else
            rbyte=rbyte<<1;
        scl(device,0);
    }
    return(rbyte);
} 



#include "iic.c"
#define max_freq 108000
#define min_freq 87500
unsigned char radio_write_data[5]={0x29,0xc2,0x20,0x11,0x00};        //要寫入TEA5767的數據
unsigned char radio_read_data[5];        //TEA5767讀出的狀態
unsigned int default_pll=0x29c2;//0x29f9;        //默認存臺的pll,87.8MHz
//unsigned int max_pll=0x339b;            //108MHz時的pll,
//unsigned int min_pll=9000;            //70MHz時的pll

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

//讀TEA5767狀態,并轉換成頻率
void radio_read(void)
{
    unsigned char i;
    unsigned char temp_l,temp_h;
    pll=0;
    iic_start();
    iic_write8bit(0xc1);        //TEA5767讀地址
    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();
}

//由頻率計算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);    //頻率單位:k
    else
        pll=(unsigned int)((float)((frequency-225)*4)/(float)32.768);    //頻率單位:k
}
//由PLL計算頻率
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);    //頻率單位:KHz
    else
        frequency=(unsigned long)((float)(npll)*(float)8.192+225);    //頻率單位:KHz
}

//手動設置頻率,mode=1,+0.1MHz; mode=0:-0.1MHz ,不用考慮TEA5767用于搜臺的相關位:SM,SUD
void search(bit mode)
{
    radio_read();        
    if(mode)
    {
        frequency+=100;
        if(frequency>max_freq)
            frequency=min_freq;
    }
    else
    {
        frequency-=100;
        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]=0x20;
    radio_write_data[3]=0x11;
    radio_write_data[4]=0x00;
    radio_write();
}

//自動搜臺,mode=1,頻率增加搜臺; mode=0:頻率減小搜臺,不過這個好像不能循環搜臺
void auto_search(bit mode)
{
    radio_read();
    get_pll();
    if(mode)
        radio_write_data[2]=0xa0;
    else
        radio_write_data[2]=0x20;    
    radio_write_data[0]=pll/256+0x40;
    radio_write_data[1]=pll%256;    
    radio_write_data[3]=0x11;
    radio_write_data[4]=0x00;
    radio_write();
    radio_read();
    while(!(radio_read_data[0]&0x80))     //搜臺成功標志
    {
        radio_read();
        disp_freq(9,1);
    }    
}