ds18b20测温电路的设计,包括主程序、读出温度子程序、复位应答子程序、写入子程序、以及有关DS18B20的程序（初始化子程序、写程序和读程序）-ds18b20 temperature circuit design, including the main program, subroutine temperature readout, the reset response subroutine, write subroutine, and the DS18B20 program (initia