本程序是在1602液晶上实现了时钟、测温、按键、定时等各种功能，程序规整，易于学习。-This program is realized in 1602 on the various functions of the LCD clock, temperature, buttons, timing, etc., structured program, easy to learn.

本程序是在1602液晶上实现了时钟及温度检测，程序十分简单，易于理解。-This program is realized in 1602 on the LCD clock and temperature detector, the program is very simple and easy to understand.

89C51通过ID模块读取ID卡号显示在1602液晶上，读取的卡号保存eeprom中，下次刷卡比对卡号后验证通过开门LED模拟的门。-89C51 through the ID module to read the ID card number displayed on the 1602 LCD, read the card number to save EEPROM, the next card to verify the card number after the door through t

超声波测距，1602液晶显示，51单片机(Ultrasonic ranging, 1602 LCD display, 51 SCM)