main.c

一个数字温度计源代码 MCU是AT89S52 温度传感器是DS18B20 温度测量范围-30 - 100 精度0.5度

//

#include "REG52.h"
#include "LedLib.h"
#include "SensorLib.h"


void main(void){
	unsigned char tempL,tempH;//the low byte and the high byte for the temperature
    char temperature;//store the final result for the convertion
	unsigned char ledTemp;
	unsigned char bitCount;
	unsigned int i;
	bit minus;

	//for debug
	//unsigned char tmp;

		
	//first we setting up the sensor
	resetSensor();
	writeSensor(SKIP_ROM);//skip search ROM, address all the ROM present on the bus
	writeSensor(WRITE_RAM);//start  to configuring the sensor
	writeSensor(0x64);//Th = 100C
	writeSensor(0x8a);//Tl = -10C
	writeSensor(0x1f);//9 bit resolution,0.5C increasment
	
	/*
	//for debug
	resetSensor();
	writeSensor(READ_ROM);
	tmp = readSensor();
	readSensor();
	readSensor();
	resetSensor();
	
	for(;1;){
		ledTemp = tmp;
			bitCount = 0;
			do{
				ledSetDigit((ledTemp % 10),bitCount,0);
				ledTemp = ledTemp / 10;
				bitCount ++;
			}while(ledTemp != 0);					
		
	}
	*/
	
	//the whole program is a infinited loop
	//we read the temperature sensor, and then send it to the led
	for(;1;){
		
		resetSensor();//reset the sensor
		writeSensor(SKIP_ROM);//skip search ROM, address all the ROM present on the bus
		writeSensor(CONVERT_T);//start temperature convert
		
		for(i = 0;i < 1000;i++){//we show up the last result while we are waiting for the convertion 
			ledTemp = temperature;                                                                                                                               
			if(minus == 1){
				ledSetDigit(5,0,0);//set digit 5		
			}else{
				ledSetDigit(0,0,0);//set digit 5
			}			
			
			bitCount = 1;
			do{
				if(bitCount == 1){
					ledSetDigit((ledTemp % 10),bitCount,1);	
				}else{
					ledSetDigit((ledTemp % 10),bitCount,0);
				}
				ledTemp = ledTemp / 10;
				bitCount ++;
			}while(ledTemp != 0);

			if(temperature < 0){
				ledSetDigit(10,bitCount,0);	
			}

				
		}
				
		resetSensor();//reset the sensor
		writeSensor(SKIP_ROM);//skip search ROM, address all the ROM present on the bus
		writeSensor(READ_RAM);//read out the result
		tempL = readSensor();//read out the higher byte for the temperature
		tempH = readSensor();//read out the lower bute for the temperature	

		if(tempL & 0x08){
			minus = 0x1;
		}else{
			minus = 0x0;
		}

		temperature = tempH << 4;
		temperature = temperature + ((tempL & 0xf0) >> 4);
		temperature = temperature - 10;
						
	}	

}