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^7。 sbit LOW=P3^6。sbit RELAY=P3^5。 //此表為 LED 的字模, 共陰數(shù)碼管 09 unsigned char code Disp_Tab[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x40}。 unsigned char code Disp2_Tab[] = {0xbf,0x86,0xdb,0xcf,0xe6,0xed,0xfd,0x87,0xff,0xef,0xc0}。 unsigned char code dotcode[4]={0,25,50,75}。unsigned long LedOut[5],LedNum1=0,LedNum2=0。void system_Ini(){ TMOD|= 0x11。 TH1 = 0xD8。 //10 TL1 = 0xF0。 IE = 0x8A。 TR1 = 1。}main(){ unsigned char i,temper,Decimalstemper。 system_Ini()。 while(1) { /********以下將讀18b20的數(shù)據(jù)送到LED數(shù)碼管顯示*************/ //從溫度傳感器得到溫度的整數(shù)部分 temper=ReadTemInteger(10,100,0x3f)。 LedNum1=temper。 //從溫度傳感器得到溫度的小數(shù)部分 Decimalstemper=ReadTemDecimals(10,100,0x3f)。 LedNum2=dotcode[Decimalstemper]。 //對小數(shù)部分進(jìn)行判斷。(~~,~~,~~,整數(shù)部分進(jìn)位) if(LedNum2==25){ LedNum2=50。 } else if(LedNum2==75){ LedNum2=0。 LedNum1++。 } //掃描鍵盤,得到報(bào)警溫度值 keydown()。//獲得鍵盤情況,判斷是否有鍵按下 if(LedNum1=dis_buf) { HIGH=0。LOW=1。RELAY=0。}//dis_buf為用戶預(yù)先設(shè)定的報(bào)警值。超過報(bào)警值則指示燈亮,否則的話,燈滅。 else {HIGH=1。LOW=0。RELAY=1。} //對數(shù)碼管段選進(jìn)行賦值。 LedOut[0]=Disp_Tab[LedNum1%1000/100]。 //百位 LedOut[1]=Disp_Tab[LedNum1%100/10]。 //十位 LedOut[2]=Disp2_Tab[LedNum1%10]。 //個(gè)位 LedOut[3]=Disp_Tab[LedNum2/10]。 //小數(shù)位 LedOut[4]=Disp_Tab[dis_buf/10]。 //個(gè)位 LedOut[5]=Disp_Tab[dis_buf%10]。 //小數(shù)位 for(i=0。 i6。 i++) { switch(i) { //138譯碼 case 0:LS138A=0。 LS138B=0。 LS138C=0。 break。 case 1:LS138A=1。 LS138B=0。 LS138C=0。 break。 case 2:LS138A=0。 LS138B=1。 LS138C=0。 break。 case 3:LS138A=1。 LS138B=1。 LS138C=0。 break。 case 4:LS138A=0。 LS138B=0。 LS138C=1。 break。 case 5:LS138A=1。 LS138B=0。 LS138C=1。 break。 } P0 = LedOut[i] 。 delay(70)。 } }} //延時(shí)程序void delay(unsigned int i){ char j。 for(i。 i 0。 i) for(j = 200。 j 0。 j)。}附錄二 外文資料翻譯資料原文DS18B20Programmable Resolution1 Wire Digital ThermometerDESCRIPTIONThe DS18B20 Digital Thermometer provides 9 to 12–bit centigrade temperature measurements and has an alarm function with nonvolatile userprogrammable upper and lower trigger points. The DS18B20 municates over a 1Wire bus that by definition requires only one data line (and ground) for munication with a central microprocessor. It has an operating temperature range of –55℃ to +125176。C and is accurate to 177?!?over the range of –10℃ to +85℃. In addition, the DS18B20 can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply.Each DS18B20 has a unique 64bit serial code, which allows multiple DS18B20s to function on the same 1–wire bus。 thus, it is simple to use one microprocessor to control many DS18B20s distributed over a large area. Applications that can benefit from this feature include HVAC environmental controls,temperature monitoring systems inside buildings, equipment ormachinery, and process monitoring and control systems.OVERVIEWFigure 1 shows a block diagram of the DS18B20, and pin descriptions are given in Table 1. The 64bit ROM stores the device’s unique serial code. The scratchpad memory contains the 2byte temperature register that stores the digital output from the temperature sensor. In addition, the scratchpad provides access to the 1byte upper and lower alarm trigger registers (TH and TL), and the 1byte configuration register. The configuration register allows the user to set the resolution of the temperaturetodigital conversion to 9, 10, 11, or 12 bits. The TH, TL and configuration registers are nonvolatile (EEPROM), so they will retain data when the device is powered down.The DS18B20 uses Dallas’ exclusive 1Wire bus protocol that implements bus munication using one control signal. The control line requires a weak pullup resistor since all devices are linked to the bus via a 3state or opendrain port (the DQ pin in the case of the DS18B20). In this bus system, the microprocessor (the master device) identifies and addresses devices on the bus using each device’s unique 64bit code. Because each device has a unique code, the number of devices that can be addressed on one bus is virtually unlimited. The 1Wire bus protocol, including detailed explanations of the mands and“time slots,” is covered in the 1WIRE BUS SYSTEM section of this datasheet.Another feature of the DS18B20 is the ability to operate without an external power supply. Power is instead supplied through the 1Wire pullup resistor via the DQ pin when the bus is high. The high bus signal also charges an internal capacitor (Cpp), which then supplies power to the device when the bus is low. This method of deriving power from the 1Wire bus is referred to as “parasite power.” As an alternative, the DS18B20 may also be powered by an external supply on VDD.OPERATION — MEASURING TEMPERATUREThe core functionality of the DS18B20 is its directtodigital temperature sensor. The resolution of the temperature sensor is userconfigurable to 9, 10, 11, or 12 bits, corresponding to increments of ℃, ℃, ℃, and ℃, respectively. The default resolution at powerup is 12bit. The DS18B20 powersup in a lowpower idle state。 to initiate a temperature measurement and AtoD conversion, the master must issue a Convert T [44h] mand. Following the conversion, the resulting thermal data is stored in the 2byte temperature register in the scratchpad memory and the DS18B20 returns to its idle state. If the DS18B20 is powered by an external supply, the master can issue “read time slots” (see the 1 WIRE BUS SYSTEM section) after the Convert T mand and the DS18B20 will respond by transmitting 0 while the temperature conversion is in progress and 1 when the conversion is done. If the DS18B20 is powered with parasite power, t