Introduction - If you have any usage issues, please Google them yourself
Contents: 1, the program purpose: to learn to use the countdown timer with countdown traffic light principle the same as two major programs, hardware requirements: digital, crystal 12M 3, P1 port is connected to the LED lights for display (p1 pick latch, eight digital bit signals and off signals are latched by p1 tube mouth up, it saves port) 4, the digital display for time