"基于单片机抢答器设计：简单稳定可靠，提高竞争公平性和参与性"

Based on the design of the single chip microcomputer buzzer, the digital buzzer is composed of expansion circuit and main circuit. The input signal of the participating team displayed on the screen is generated by priority encoding circuit, latch circuit, and decoding circuit etc.; the expansion circuit realizes the timing function displayed on the screen, and the signal generated by the second pulse is composed of the timing circuit and decoding circuit. The main circuit is composed of control circuit, host switch and start alarm circuit. The formation of the digital buzzer is through wiring, debugging, and welding work. In order to make the peripheral circuit simpler, the single chip microcomputer simplifies the peripheral hardware circuit and delegates many tasks to software programming. The single chip microcomputer is not only convenient to apply, but also has small size, low price, stability, and reliability. If the application program gives the single chip microcomputer a new "life", then the buzzer system "body" is given by the hardware structure of the single chip microcomputer system, which makes it have the advantages of low cost, simple circuit, and reliable operation in front of general buzzers. The buzzer is designed to facilitate contestants to participate in the buzzer quiz, and the contestant who buzzes in first must answer the question. The buzzer not only tests the contestants' knowledge but also their reaction speed as well as requiring a certain amount of courage and skill. The buzzer system is fair and just for all contestants, because they all start from the same line. Keywords: timing circuit, buzzer circuit, alarm circuit.