基于AT89S52单片机的数字温度计设计(2)

temp_data[0]=read_byte(); //温度低8位 temp_data[1]=read_byte(); //温度高8位 ow_reset();

write_byte(0xCC); // Skip ROM write_byte(0x44); // 发转换命令

}

work_temp()//温度数据处理函数 {

uchar n=0; // if(temp_data[1]>127)

{temp_data[1]=(256-temp_data[1]);temp_data[0]=(256-temp_data[0]);n=1;}//负温度求补码 display[4]=temp_data[0]&0x0f;display[0]=ditab[display[4]];

display[4]=((temp_data[0]&0xf0)>>4)|((temp_data[1]&0x0f)<<4);// display[3]=display[4]/100; display[1]=display[4]0; display[2]=display[1]/10; display[1]=display[1];

if(!display[3]){display[3]=0x0A;if(!display[2]){display[2]=0x0A;}}//最高位为0时都不显示 if(n){display[3]=0x0B;}//负温度时最高位显示\}

main()//主函数 {

Disdata=0xff; //初始化端口 discan=0xff;

for(h=0;h<4;h++){display[h]=8;}//开机显示8888 ow_reset(); // 开机先转换一次 write_byte(0xCC); // Skip ROM write_byte(0x44); // 发转换命令 for(h=0;h<500;h++)

{scan();} //开机显示\秒 while(1) {

read_temp(); //读出18B20温度数据 work_temp(); //处理温度数据 for(h=0;h<500;h++)

{scan();} //显示温度值2秒 } }

六 系统仿真及调试

1 软件调试

R14U29.0VCCDQGND3214.7kDS18B20U1171615141312111028272625242322213233343536373839P3.7/RDP3.6/WRP3.5/T1P3.4/T0P3.3/INT1P3.2/INT0P3.1/TXDP3.0/RXDP2.7/A15P2.6/A14P2.5/A13P2.4/A12P2.3/A11P2.2/A10P2.1/A9P2.0/A8P0.7/AD7P0.6/AD6P0.5/AD5P0.4/AD4P0.3/AD3P0.2/AD2P0.1/AD1P0.0/AD0AT89S52P1.7P1.6P1.5P1.4P1.3P1.2P1.1P1.087654321R3R2R4510R5510R6510R7510R8510R9510510510EAALEPSEN313029C2510ufU3:C67407R110kRST9R106.8kXTAL218U3:B12MHZ374074R1110kXTAL119C110pC310p17407U3:A2R1210kU3:D974078R1310k 图5 仿真图1

R14U214.0VCCDQGND3214.7kDS18B20U1171615141312111028272625242322213233343536373839P3.7/RDP3.6/WRP3.5/T1P3.4/T0P3.3/INT1P3.2/INT0P3.1/TXDP3.0/RXDP2.7/A15P2.6/A14P2.5/A13P2.4/A12P2.3/A11P2.2/A10P2.1/A9P2.0/A8P0.7/AD7P0.6/AD6P0.5/AD5P0.4/AD4P0.3/AD3P0.2/AD2P0.1/AD1P0.0/AD0AT89S52P1.7P1.6P1.5P1.4P1.3P1.2P1.1P1.087654321R3R2R4510R5510R6510R7510R8510R9510510510EAALEPSEN313029C2510ufU3:C67407R110kRST9R106.8kXTAL218U3:B12MHZ374074R1110kXTAL119C110pC310p17407U3:A2R1210kU3:D974078R1310k 图6 仿真图2