//-----------------------------------------------------------------------------
// T2Cal33x.c
//-----------------------------------------------------------------------------
// 版權歸新華龍電子有限公司所有
//
// 作者：Robi Ken 
// 日期: 2004.12.30
//
// 功能：使用片內溫度傳感器實驗
// 目標板: C8051F33x
// 開發(fā)工具: Silicon Laboratories  IDE 

//-----------------------------------------------------------------------------
// 頭文件
//-----------------------------------------------------------------------------

#include <c8051f330.h>                 
#include <stdio.h>

//-----------------------------------------------------------------------------
// F31x’定時器2的16位SFR
//-----------------------------------------------------------------------------

sfr16 TMR2RL   = 0xca;                 
sfr16 TMR2     = 0xcc;                 
sfr16 ADC0     = 0xbd;                

//-----------------------------------------------------------------------------
// 常量定義
//-----------------------------------------------------------------------------

#define SYSCLK      24500000           
#define BAUDRATE        9600           
#define TIMER2_RATE     1000           


sbit LED = P1^3;                       
//-----------------------------------------------------------------------------
// 溫度傳感器參數(shù)
//-----------------------------------------------------------------------------
#define AMB_TEMP           25          
                                       

#define TEMP_SENSOR_GAIN   2860        

#define VREF               2430        // ADC 基準電壓 (mV)

#define SOAK_TIME          15         


//-----------------------------------------------------------------------------
// 全局變量
//-----------------------------------------------------------------------------

unsigned int code TEMP_OFFSET = 0xFFFF;

//-----------------------------------------------------------------------------
// 功能函數(shù)
//-----------------------------------------------------------------------------

void SYSCLK_Init (void);
void ADC0_Init (void);
void UART0_Init (void);
void PORT_Init (void);
void Timer2_Init (int);

int get_temp (void);
void calibrate(void);
unsigned int measure(void);
void wait_one_second (void);

//-----------------------------------------------------------------------------
// 主程序
//-----------------------------------------------------------------------------

void main (void) {

   unsigned temperature;


   PCA0MD &= ~0x40;                    // 禁止看門狗 
                                       
   PORT_Init();                        
   SYSCLK_Init ();                     

   ADC0_Init ();                       
   Timer2_Init(SYSCLK/TIMER2_RATE);    
   UART0_Init();

   AD0EN = 1;                          // 使能 ADC0

   if (TEMP_OFFSET == 0xFFFF) {        
      printf ("Calibrating...\n");
      calibrate ();                    
   } else {
      printf ("Not calibrating.\n");
   }

   while (1) {
      
      LED = 1;
      temperature = get_temp ();
      LED = 0;
      printf ("Temperature = %+02d hundredths degrees C\n", temperature);
   }
}

//-----------------------------------------------------------------------------
// 初始化子程序
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// 端口初始化
//-----------------------------------------------------------------------------

//
// P0.4 - UART TX
// P0.5 - UART RX
// P3.3 - LED

void PORT_Init (void)
{
   P0SKIP  |= 0x01;                    
   P0MDIN  |= 0x01;                    
   P0MDOUT |= 0x10;                    
   P1MDOUT |= 0x08;                    
   XBR0    = 0x01;                                         
   XBR1    = 0x40;                     
}

//-----------------------------------------------------------------------------
// 系統(tǒng)時鐘初始化
//-----------------------------------------------------------------------------


void SYSCLK_Init (void)
{
   OSCICN |= 0x03;                     
                                       
   RSTSRC  = 0x04;                     

}

//-----------------------------------------------------------------------------
// ADC0初始化、使能、中斷
//-----------------------------------------------------------------------------
//
void ADC0_Init (void)
{
   ADC0CN = 0x40;                      
                                        
                                       
   AMX0P  = 0x10;                      
   AMX0N  = 0x11;                      
   ADC0CF = (SYSCLK/3000000) << 3;     

   ADC0CF &= ~0x04;                    
   REF0CN = 0x0e;                      
                                       

   EIE1 &= ~0x08;                      
}

//-----------------------------------------------------------------------------
// UART0_Init
//-----------------------------------------------------------------------------
//
void UART0_Init (void)
{
   SCON0 = 0x10;                       
                                       
                                       
                                       
                                       
   if (SYSCLK/BAUDRATE/2/256 < 1) {
      TH1 = -(SYSCLK/BAUDRATE/2);
      CKCON &= ~0x0B;                  // T1M = 1; SCA1:0 = xx
      CKCON |=  0x08;
   } else if (SYSCLK/BAUDRATE/2/256 < 4) {
      TH1 = -(SYSCLK/BAUDRATE/2/4);
      CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 01                  
      CKCON |=  0x09;
   } else if (SYSCLK/BAUDRATE/2/256 < 12) {
      TH1 = -(SYSCLK/BAUDRATE/2/12);
      CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 00
   } else {
      TH1 = -(SYSCLK/BAUDRATE/2/48);
      CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 10
      CKCON |=  0x02;
   }

   TL1 = TH1;                         
   TMOD &= ~0xf0;                      
   TMOD |=  0x20;                       
   TR1 = 1;                            
   TI0 = 1;                            
}

//-----------------------------------------------------------------------------
// 定時器2系統(tǒng)時鐘中斷
//-----------------------------------------------------------------------------
//
void Timer2_Init (int counts)
{
   TMR2CN = 0x00;                     
                                       
                                       
   CKCON |= 0x10;                      

   TMR2RL  = -counts;                  
   TMR2    = TMR2RL;                   
   ET2 = 0;                            
   TR2 = 1;                            
}


//-----------------------------------------------------------------------------
// 等待處理結束
//-----------------------------------------------------------------------------
// 
void wait_soak_time (unsigned char soak_time)
{
   unsigned char i;

   for( i = soak_time; i != 0; i--) {
      wait_one_second();
      printf ("Soaking...%d\n", (int) i);
   }
}
  
//-----------------------------------------------------------------------------
// 延時1秒
//-----------------------------------------------------------------------------

void wait_one_second (void)
{
   unsigned int count;
   TF2H = 0;                           // 清除定時器2溢出標志
   TR2 = 1;                            // 開始定時器2
   
   for (count = TIMER2_RATE; count != 0; count--) {
      while (!TF2H);                   // 等待溢出
      TF2H = 0;                        
   }

   TR2 = 0;                            // 停止定時器2
}

//-----------------------------------------------------------------------------
// 校準
//-----------------------------------------------------------------------------
//
void calibrate (void)
{

   bit EA_state=EA;                    // 保持EA狀態(tài)
   unsigned char xdata * codePtr;      
                                       
   unsigned int code* data pread;      

   long temp_offset;                   
   pread = (unsigned int code *) TEMP_OFFSET;

   wait_soak_time(SOAK_TIME);          
   temp_offset= (long) measure ();     

   
   temp_offset = temp_offset - ((long) AMB_TEMP * 
                 TEMP_SENSOR_GAIN / VREF * 65536 / 1000);
   
   codePtr=(unsigned char xdata*) &TEMP_OFFSET;               
                                       

   EA = 0;                             // 禁止中斷


   FLKEY=0xA5;                         
                                      
 
   PSCTL |= 0x01;                      // 允許寫FLASH
   *codePtr = (temp_offset>>8);        

   PSCTL &= ~0x01;                     // 禁止寫FLASH

   codePtr++;                          
                                       
                                       
 
   FLKEY=0xA5;                         
   FLKEY=0xF1;                         
                                       
 
   PSCTL |= 0x01;                      // 允許寫FLASH

   *codePtr =temp_offset;              
     
      
   PSCTL = 0x00;                       //禁止寫FLASH
   EA = EA_state;                      // 恢復中斷狀態(tài)

}

//-----------------------------------------------------------------------------
// measure
//-----------------------------------------------------------------------------
// 
unsigned int measure (void)
{
   unsigned i;                         
   unsigned long accumulator=0L;       
                                       
   unsigned int currval;

   AD0INT = 0;
   AD0BUSY = 1;

   
   i = 0;
   do 
   {
      while (!AD0INT);                 
      AD0INT = 0;                      

      currval=ADC0;                             
      AD0BUSY = 1;                     
      accumulator += currval;          
      i++;                             
   } while (i != 16383);
   return (unsigned int) (accumulator >> 8);
   // shift to obtain a 16-bit result (14 + 10 = 24 - 8 = 16) bits
}


int get_temp (void)
{
   unsigned int ADC_code;
   long result;
   
   ADC_code = measure();
   
   result = ADC_code - TEMP_OFFSET;

   // result = result * (VREF / 65536) * (1000 / TEMP_SENSOR_GAIN) * ( 100 )
   // the equation above is re-arranged for fixed-point math.

   result = result * (long) VREF / 256 * 1000 / TEMP_SENSOR_GAIN * 100 / 256;
   
   return (int) result;
}