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//調試總結:
//顯著的問題是,寫時序、讀時序中,PIC MCU向總線寫1是通過改方向為輸入方向由上拉電阻拉高數(shù)據(jù)線實現(xiàn)的,而非在輸出方向下輸出1,與AVR不同
//某IO口8位未全使用時,對整個IO口讀取進行位運算無效
//使用if(dat2&0xf8==0xf8)時,進錯分支導致顯示亂碼仍未找到原因,用if(dat2>=240)代替正常
- #include<pic.h>
- #define uchar unsigned char
- #define uint unsigned int
- #define rs_h (PORTC|=0x01)
- #define rs_l (PORTC&=0xfe)
- #define rs_o (TRISC&=0xfe)
- #define rw_h (PORTC|=0x02)
- #define rw_l (PORTC&=0xfd)
- #define rw_o (TRISC&=0xfd)
- #define en_h (PORTC|=0x04)
- #define en_l (PORTC&=0xfb)
- #define en_o (TRISC&=0xfb)
- #define temp_h (PORTC|=0x08)
- #define temp_l (PORTC&=0xf7)
- #define temp_o (TRISC&=0xf7)
- #define temp_i (TRISC|=0x08)
- #define led_o (TRISC&=0xef)
- #define led_l (PORTC&=0xef)
- #define led_h (PORTC|=0x10)
- #define LCD PORTB
- uchar dat1,dat2;//保存讀出的溫度z
- unsigned long int dat;
- void delayms(uint x) //4M晶振下,延時1ms
- {
- uint y,z;
- for(y=x;y>0;y--)
- for(z=110;z>0;z--);
- }
- void Ds18b20_reset(void)//DS18B20初始化
- {
- uint count;
- uchar i,flag=1;
- temp_o;
- temp_l;
- for(count=60;count>0;count--);//延時480us
- temp_i;
- while(flag)
- {
- //temp=PORTC;//此例中,C口部分引腳未使用處于高阻態(tài),對整個C口的讀取無效,所以if(RC3)不能換成if(temp&0x08==0x08)
- if(RC3)//temp&0x08==0x08)
- flag=1;
- else
- flag=0;
- }
- led_o;
- led_l;//開指示燈
- for(count=60;count>0;count--);//延時480us
- }
- void Ds18b20_write(uchar datt)//向DS18B20寫一個字節(jié)
- {
- uchar count;
- uchar i;
- temp_o;
- for(i=8;i>0;i--)
- {
- temp_o;
- temp_l;
- for(count=1;count>0;count--);
- //temp_h;//不能有此語句
- if(datt&0x01==0x01)
- temp_i;
- else
- {
- temp_o;
- temp_l;
- }
- for(count=23;count>0;count--);//延時60us
- temp_i;
- for(count=1;count>0;count--);
- datt>>=1;
- }
- }
- uchar Ds18b20_read(void) //從DS18B20讀一個字節(jié)
- {
- uchar i,datt;
- uchar count;
- for(i=8;i>0;i--)
- {
- datt>>=1;
- temp_o;
- temp_l;
- for(count=1;count>0;count--);
- temp_i;//改為輸入方向時,上拉電阻把數(shù)據(jù)線拉高,釋放總線,此語句必須有,參考datasheet的P15
- for(count=1;count>0;count--);
- if(RC3)//(PORTC&0x08==0x08)//換成(PORTC&0x08==0x08)后程序不正確
- datt|=0x80;
- for(count=23;count>0;count--);//延時60us
- }
- return datt;
- }
- void lcd_com(uchar com)//向LCD1602寫命令
- {
- rs_o;
- rw_o;
- en_o;
- TRISB=0x00;//配置RB為輸出方向
- rs_l;
- rw_l;
- LCD=com;
- delayms(1);
- en_h;
- delayms(1);
- en_l;
- delayms(1);
- }
- void lcd_dat(uchar dat)//向LCD1602寫數(shù)據(jù)
- {
- rs_o;
- rw_o;
- TRISB=0x00;//配置RB為輸出方向
- en_o;
- rs_h;
- rw_l;
- LCD=dat;
- delayms(1);
- en_h;
- delayms(1);
- en_l;
- delayms(1);
- }
- void lcd_write(uchar c,uchar r,uchar dat)//向LCD1602指定行、指定列、寫數(shù)據(jù)
- {
- lcd_com(0x80+0x40*c+r);
- lcd_dat(dat);
- delayms(1);
- }
- void lcd_init(void)//LCD1602初始化,初始化后第一行顯示temperature:,第二行顯示.C
- {
- lcd_com(0x38);
- lcd_com(0x0c);
- lcd_com(0x06);
- lcd_write(0,2,0x54);
- lcd_write(0,3,0x65);
- lcd_write(0,4,0x6d);
- lcd_write(0,5,0x70);
- lcd_write(0,6,0x65);
- lcd_write(0,7,0x72);
- lcd_write(0,8,0x61);
- lcd_write(0,9,0x74);
- lcd_write(0,10,0x75);
- lcd_write(0,11,0x72);
- lcd_write(0,12,0x65);
- lcd_write(0,13,0x3a);
- lcd_write(1,11,0xdf);
- lcd_write(1,12,0x43);
- }
- void show(void)//把溫度值送LCD1602顯示
- {
- uchar flag;
- uchar t[4];
- uint temp;
- if(dat2>=240)//遺留問題,溫度為25時讀出dat1=144,dat2=1正確,但卻進入if(dat2&0xf8==0xf8)分支導致顯示亂碼;
- {
- dat= (~(dat2*256+dat1)+1)*(0.0625*10);//取反加一,保留一位小數(shù)
- flag=1;
- }
- else
- {
- dat=(dat2*256+dat1)*(0.0625*10);
- flag=0;
- };
- temp=dat%10;
- t[0]=(0x30+temp);
- temp=dat%100;
- temp=temp/10;
- t[1]=(0x30+temp);
- temp=dat%1000;
- temp=temp/100;
- t[2]=(0x30+temp);
- temp=dat/1000;
- t[3]=(0x30+temp);
- if(flag==1)//負溫度顯示
- {
- lcd_write(1,10,t[0]);
- lcd_write(1,9,0xa5);
- lcd_write(1,8,t[1]);
- lcd_write(1,7,t[2]);
- lcd_write(1,6,t[3]);
- lcd_write(1,5,0x2d);
- }
- if(flag==0)//正溫度顯示
- {
- lcd_write(1,10,t[0]);
- lcd_write(1,9,0xa5);
- lcd_write(1,8,t[1]);
- lcd_write(1,7,t[2]);
- lcd_write(1,6,t[3]);
- lcd_write(1,5,0x20);//顯示空格,刷掉負號
- }
- }
- void main(void)
- {
- lcd_init();
- while(1)
- {
- Ds18b20_reset();
- Ds18b20_write(0xcc);
- Ds18b20_write(0x44);//發(fā)送溫度轉換命令
- delayms(1000);//延時1s,等待溫度轉換完成
- Ds18b20_reset();
- Ds18b20_write(0xcc);
- Ds18b20_write(0xbe);//發(fā)送讀溫度寄存器命令
- dat1=Ds18b20_read();
- dat2=Ds18b20_read();
- show();
- led_h;//關指示燈
- delayms(2000);
- }
- }
復制代碼
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PICds18b20(4M).zip
2019-9-24 22:16 上傳
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87.02 KB, 下載次數(shù): 36, 下載積分: 黑幣 -5
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