单片机 18b20如何在1602显示屏上正常显示带一位小数温度

ID:753342 · 发表于 2020-5-16 16:17

void DS18B20_ReSet(void)
{
uchar i;
DQ = 0;
i = 240;
while (--i);
DQ = 1;
i = 30;
while (--i);
while (~DQ);
i = 4;
while (--i);

void DS18B20_WriteByte(uchar dat)
{
uchar j;
uchar btmp;

for (j = 0; j < 8; j++)
{
      btmp = 0x01;
      btmp = btmp << j;
      btmp = btmp & dat;

      if (btmp > 0) // D′1
      {
         DQ = 0;
         Delay15us();
         DQ = 1;
         Delay15us();
         Delay15us();
         Delay15us();
         Delay15us();
      }
      else          //
      {
         DQ = 0;
         Delay15us();
         Delay15us();
         Delay15us();
         Delay15us();
         DQ = 1;
         Delay15us();
      }

}

int DS18B20_ReadTemp(void)
{
uchar j;
int b, temp = 0;
EA = 0;

DS18B20_ReSet();
DS18B20_WriteByte(0xcc);
DS18B20_WriteByte(0x44);

DS18B20_ReSet();
DS18B20_WriteByte(0xcc);
DS18B20_WriteByte(0xbe);

for (j = 0; j < 16; j++)
{
      DQ = 0;
      _nop_();
      _nop_();
      DQ = 1;
      Delay15us();
      b = DQ;
      Delay15us();
      Delay15us();
      Delay15us();
      b = b << j;
      temp = temp | b;
}

EA = 1;
temp = temp * 0.0625+0.5;

return (temp);
}

void WaitForEnable(void)
{
P0 = 0xff;
LcdRs_P = 0;
LcdRw_P = 1;
_nop_();
LcdEn_P = 1;
_nop_();
_nop_();
while (P0 & 0x80);
LcdEn_P = 0;

}

void LcdWriteCmd(uchar cmd)
{
WaitForEnable();
LcdRs_P = 0;
LcdRw_P = 0;
LcdEn_P = 0;
P0 = cmd;
DelayMs(5);
LcdEn_P = 1;
DelayMs(5);
LcdEn_P = 0;
DelayMs(5);
}

void LcdWriteData(uchar dat)
{
WaitForEnable();
LcdRs_P = 1;
LcdRw_P = 0;
LcdEn_P = 0;
P0 = dat;
DelayMs(5);
LcdEn_P = 1;
DelayMs(5);
LcdEn_P = 0;
DelayMs(5);
}

void LcdInit()
{
LcdWriteCmd(0x38);
LcdWriteCmd(0x0C);
LcdWriteCmd(0x06);
LcdWriteCmd(0x01);
LcdWriteCmd(0x80);
}
void LcdGotoXY(uchar line, uchar column)
{

if (line == 0)
      LcdWriteCmd(0x80 + (column & 0x0F));

if (line == 1)
      LcdWriteCmd(0x80 + 0x40 + (column & 0x0F));
}
void LcdPrintStr(uchar *str)
{
while (*str != '\0')
      LcdWriteData(*str++);
}
void LcdPrintNum1(uchar num)
{
LcdWriteData(0x30 + num%1000/100);
LcdWriteData(0x30 + num%100/10);
LcdWriteData(0x30 + num%10/1);
LcdWriteData('.');
LcdWriteData(0x30 + num/1);
}
void LcdPrintNum2(uint num)
{
if (num < 0)

      LcdWriteData('-');
      num = 0 - num;
}

else
{

LcdWriteData(0x30 + num%1000/100);
}
LcdWriteData(0x30 + num%100/10);
LcdWriteData(0x30 + num%10/1);
LcdWriteData('.');
LcdWriteData(0x30 + num/1);

}

ID:584814 · 发表于 2020-5-17 19:34

temp = temp * 0.0625+0.5; 改为
temp = temp * 0.625+0.5;然后个位就是小数点后第一位,想两位小数就再放大十倍
另:你的程序里好像没有考虑温度零下的情况,类似程序可以在本坛里大把地找

ID:753342 · 发表于 2020-5-18 09:13

man1234567 发表于 2020-5-17 19:34
temp = temp * 0.0625+0.5; 改为
temp = temp * 0.625+0.5;然后个位就是小数点后第一位,想两位小数就再放 ...

这个我知道，但是上下限设置那里要怎么改呢

ID:282850 · 发表于 2020-5-18 10:14

Q605929691 发表于 2020-5-18 09:13
这个我知道，但是上下限设置那里要怎么改呢

DS18不需要考虑上下限，如果控制中要if判定上下限，原理与沙发说的一样。
上限71.5度， if(temp>715) ....
下限23.5度，if(temp<235) ....
如此简单，心中有小数点，它就有了小数点。

ID:753342 · 发表于 2020-5-18 20:50

f556 发表于 2020-5-18 10:14
DS18不需要考虑上下限，如果控制中要if判定上下限，原理与沙发说的一样。
上限71.5度， if(temp>715) .. ...

不考虑上下限温度单纯放大十倍的话，1602温度，上下限显示设置同步，读出来的上下限个位会显示在小数点后一位，百位十位为0，无法跟温度比较报警，

#include <main.h>

volatile unsigned char beep = 0;

int Tem_H = 0;
int Tem_L = 0;

ID:753342 · 发表于 2020-5-18 20:53

f556 发表于 2020-5-18 10:14
DS18不需要考虑上下限，如果控制中要if判定上下限，原理与沙发说的一样。
上限71.5度， if(temp>715) .. ...

#include <main.h>

volatile unsigned char beep = 0;

int Tem_H = 0;
int Tem_L = 0;

void ISP_Disable()
{
ISP_CONTR = 0;
ISP_ADDRH = 0;
ISP_ADDRL = 0;
}
unsigned char EEPROM_Read(unsigned int add)
{
ISP_DATA  = 0x00;
ISP_CONTR = 0x83;
ISP_CMD = 0x01;
ISP_ADDRH = (unsigned char)(add >> 8);
ISP_ADDRL = (unsigned char)(add & 0xff);
// ¶ÔSTC89C51ÏμáDà′Ëμ￡¬Ã¿′ÎòaD′èë0x46￡¬ÔùD′èë0xB9,ISP/IAP2Å»áéúD§
ISP_TRIG  = 0x46;
ISP_TRIG  = 0xB9;
_nop_();
ISP_Disable();
return (ISP_DATA);
}
void EEPROM_Write(unsigned int add, unsigned char ch)
{
ISP_CONTR = 0x83;
ISP_CMD = 0x02;
ISP_ADDRH = (unsigned char)(add >> 8);
ISP_ADDRL = (unsigned char)(add & 0xff);
ISP_DATA  = ch;
ISP_TRIG  = 0x46;
ISP_TRIG  = 0xB9;
_nop_();
ISP_Disable();
}
void Sector_Erase(unsigned int add)
{
ISP_CONTR = 0x83;
ISP_CMD = 0x03;
ISP_ADDRH = (unsigned char)(add >> 8);
ISP_ADDRL = (unsigned char)(add & 0xff);
ISP_TRIG  = 0x46;
ISP_TRIG  = 0xB9;
_nop_();
ISP_Disable();
}

帐号		自动登录	找回密码
密码			立即注册