Picproje Elektronik Sitesi

Merhaba arkadaşlar. stm32f103c8 ile ntc termometre yapıyorum (hal kütüphanesi kullanmadan registerlar üzerinden yazarak).Kod bu haliyle çalışıyor fakat tam stabil degil son basamaktaki deger sürekli oynuyor adc yi nasıl daha stabil hale getirebilirim?
#include "stm32f10x.h"                  // Device header
#include "math.h"
float sicaklik = 0;
char analog[10];
char analog2[10];
int isi;
int a=0;
void int2char(int num, char str[])
{
  char lstr[30];
   int cnt = 0;
  int div = 10;
  int j = 0;



while( num >= div)
{
lstr[cnt] = num % div + 0x30;
num /= 10;
cnt++;
}
lstr[cnt] = num + 0x30;
for(j= cnt ; j >=0;j--)
{
str[cnt-j] = lstr[j];
}
   
   
}

void DelayUs(unsigned long t)
{
for(;t>0;t--)
{
SysTick->LOAD = 72;
   SysTick->VAL = 0;
   while((SysTick->CTRL & 0x00010000) == 0);
}
}


void lcd_cmd(unsigned char data)
{
//pin_output(0,11);
GPIOA->ODR &=~0x100;//lcd_rs(LOW);
GPIOA->ODR &=~0x200;//lcd_rw(LOW);
DelayUs(10);
GPIOA->ODR |=0x400;//lcd_e(HIGH);
DelayUs(5);
GPIOA->ODR &= 0xff0f;
GPIOA->ODR |= (data & 0x00f0);
DelayUs(10);
GPIOA->ODR &=~0x400;//lcd_e(LOW);

DelayUs(20);

GPIOA->ODR |=0x400;//lcd_e(HIGH);
DelayUs(5);
GPIOA->ODR &= 0xff0f;
GPIOA->ODR |= ((data << 4) & 0x00f0);
DelayUs(10);
GPIOA->ODR &=~0x400;//lcd_e(LOW);
}

void lcd_data(unsigned char data)
{
//pin_output(4,7);
GPIOA->ODR |=0x100;//lcd_rs(HIGH);
GPIOA->ODR &=~0x200;//lcd_rw(LOW);
DelayUs(10);
GPIOA->ODR |=0x400;//lcd_e(HIGH);
DelayUs(5);
GPIOA->ODR &= 0xff0f;
GPIOA->ODR |= (data & 0x00f0);
DelayUs(10);
GPIOA->ODR &=~0x400;//lcd_e(LOW);

DelayUs(20);

GPIOA->ODR |=0x400;//lcd_e(HIGH)
DelayUs(5);
GPIOA->ODR &= 0xff0f;
GPIOA->ODR |= ((data << 4) & 0x00f0);
DelayUs(10);
GPIOA->ODR &=~0x400;//lcd_e(LOW)
}

void lcd_send( char str[])
{
int i = 0;
while(str[i])
{
lcd_data(str[i]);
i++;
DelayUs(100);
}

}


void lcd_msg(unsigned char line_1_2, unsigned char pos_0_16, char msg[])
{
short pos = 0;
if(line_1_2==1)
{
pos = 0;
}
else if(line_1_2==2)
{
pos = 0x40;
}
lcd_cmd(0x80 +pos + pos_0_16);
DelayUs(100);
lcd_send(msg);
}



int main(void)
{
// initialize the delay function (Must initialize)
SysTick->CTRL = 0;
SysTick->LOAD = 0x00FFFFFF;
SysTick->VAL = 0;
SysTick->CTRL = 5;


//pin_output(4,11);
RCC->APB2ENR = 0x04; /// port a aktif
GPIOA->CRL   = 0x33330000; /// pin 3 ü çikis olarak ayarla
GPIOA->CRH   = 0x00003333; /// pin 3 ü çikis olarak ayarla
GPIOA->CRL &= 0xFFFFF0FF; /// A3 pini resetlendi
GPIOA->CRL |= 0x00000000; //a2 sifir
DelayUs(20000);
GPIOA->ODR |=0x100;//lcd_rs(LOW);
GPIOA->ODR |=0x200;//lcd_rw(LOW);
DelayUs(10);
GPIOA->ODR |=0x400;//lcd_e(HIGH);
DelayUs(5);
GPIOA->ODR &= 0xff0f;
GPIOA->ODR |= 0x30; // 8 bit communication mode
DelayUs(10);
GPIOA->ODR &=~0x400;//lcd_e(LOW);

DelayUs(20000);


GPIOA->ODR &=~0x100;//lcd_rs(LOW);
GPIOA->ODR &=~0x200;//lcd_rw(LOW);
DelayUs(10);
GPIOA->ODR |=0x400;//lcd_e(HIGH);
DelayUs(5);
GPIOA->ODR &= 0xff0f;
GPIOA->ODR |= 0x20; // 4 bit communication mode
DelayUs(10);
GPIOA->ODR &=~0x400;//lcd_e(LOW);


lcd_cmd(0x2C); // 4 bit communication mode / 2 lines
DelayUs(5000);
lcd_cmd(0x0C); // Display ON
DelayUs(5000);
lcd_cmd(0x01); // Clear Display
DelayUs(5000);
lcd_cmd(0x02); // Get back to initial address
DelayUs(5000);

lcd_msg(1, 0,"Sicaklik(C)");
RCC->APB2ENR |= 0x201; //ADC 1 interface clock enable
ADC1->SQR3 = 2;  //düzenli sirayla ilk dönüsüm 
ADC1->SQR1 &= ~(0xf << 20);//adc kanal dizisi uzunlugu
    ADC1->SMPR2 |= (0x1); //7.5 döngü
    //12mhz: 7.5+12.5 =20 hz ->3.3us(mikro Saniye)
    ADC1->CR2 &= ~(1 << 11); // right alignment
    ADC1->CR2 |= 2|1; //adc açik ve surekli
    ADC1->CR2 |= (1<<3);//kalibrasyon reset
    ADC1->CR2 |= (1<<2);// kalibrasyon
    ADC1->CR2 |=1; //adc açik
while(1)
{
  sicaklik = log(((40950000 / ADC1->DR) - 10000));
  sicaklik = 1 / (0.001129148 + (0.000234125 + (0.0000000876741 * sicaklik * sicaklik)) * sicaklik);
  isi = (sicaklik - 273.15)*100;
int2char(isi,analog);
lcd_msg(2, 2,analog);
if(isi<1000)
{
a=3;
}
else if(isi<10000)
{
     a=4;
}
    else
{
     a=5;
}
isi=isi%100;
int2char(isi,analog2);
lcd_msg(2, a,".");
lcd_msg(2, a+1,analog2);
lcd_msg(2, a+3,"     ");
DelayUs(250000);
}

}