2051 comparator analog AD source program (C language)

2051 comparator analog AD source program (C language)

/* io allocation: *
;* OUTPUT: *
;* P1.0 ...... analog input *
;* P1.1 ...... DA input comparison reference voltage     *
;* P1.2~7..... R-2R DA resistor network *
;* P3.7 ......  LED  analog brightness output *
;* CPU C LOC K EQU 6M */
//xiaoqi last edit in 2001.11
//#pragma  SRC 
＃i nclude "AT89x051.h"
＃i nclude
＃i nclude
＃i nclude

// Macro definition of variable type identifier, everyone likes to do this
#define Uchar unsigned char
#define Uint unsigned int

#define Ledlight() (P3 &= 0x7f)
#define Leddark()  (P3 |= 0x80)

sbit P36 = P3^6; // internal judgment pin of comparator
sbit LED = P3^7; // a light emitting diode to observe brightness changes

//Internal flag bit definition
bit less; //Compare if it is greater than 1. Less than, 0. Greater than

// Global variable definition
Uchar timer1, // Universal delay counter
 timer2, // Key buzzer response timer
 adcdata, // ad conversion variable
 PWM 1; // PWM output ratio

// Function list
void DelayMs(unsigned int number); // millisecond delay void timers0(); // Scan and display the digital tube
in the timer interrupt (ct0) void Initall(void); // System initialization void timers1(void); // TC1 timer interrupt is used to scan the display and keyboard Uchar adcread(void); // adc conversion program

void main(void)  using 0
{
 DelayMs(120);
 Initall();
 pwm1 = adcread();
 LED=1;
 while(1) 
 {
  pwm1 = adcread();
  timer2=10;
  while (timer2);
 }
}

// millisecond delay
void DelayMs(unsigned int number) 
{
 unsigned char temp;

 for(;number!=0;number--) 
  for(temp=112;temp!=0;temp--);
}

/****************************************
  Do PWM output of LED in timer interrupt
****************************************/
void timers0() interrupt 1 using 1 
{
 TH0 = 0xff;
 TL0 = 0xd0;
 timer1--;
 if (timer1==pwm1)LED=0;
 if (timer1==0){
  LED=1;
  timer1=0x40;
  timer2--;
  };
}

/****************

;* 6-bit ADC conversion
;****************/
Uchar adcread(void)
{
 Uchar i=0x3f,temp=0;
 P36 =1;
 P1 = 3; _nop_();_nop_(); // Start from zero
 while ((i--)&& (P36))
  {
  temp += 4;
  P1 = temp|3;
  _nop_(); 
  }
 temp >>= 2;
 return temp;
}

/****************
;* System initialization
;********************/
void Initall(void)
{
 TMOD = 0x11; // 0001 0001 hexadecimal counter
 IP = 0x8; // 0000 1000 t1 priority
        IE = 0x8A; // 1000 1010 t0,t1 interrupt enable
 TCON = 5; // 0000 0101 external interrupt low level trigger
        TR0 = 1; // Turn on the timer interrupt, which is already turned on in IE, and indicate it again
 TR1 = 0;
        ET0 = 1;
 ET1 = 0;
        P1 = 0xff;
}
 
/*************************************
  TC1 timer interrupt is used to scan the display and keyboard (ct1)
*************************************/
void timers1(void) interrupt 3 using 2 
{
_nop_(); //Not enabled in the experiment
}