单片机入门的书，很适合 初学者，U1=89C51 U2=555 U3=MAX232 U4=24C01 U6＝X25045看门狗 X1=共阳数码管 -Singlechip book entry, it is suitable for beginners, U1 = 89C51U2 = 555U3 = MAX232U4 = 24C01U6 = X25045 watchdog X1 = total yang digital tube

555可调pwm发生器，用单片机控制，89C51-555 Adjustable pwm generator, with MCU control, 89C51

实现风速检测，通过89c51和555定时器在lcd上显示。-Wind speed detection through the 89c51 and 555 timer on the LCD display.