说明：  随着居民生活水平的不断提高，自行车不再仅仅是普通的运输、代步的工具，而是成为人们娱乐、休闲、锻炼的首选。这就为自行车的速度里程表的诞生提供了条件,一款经济实惠的速度里程表能够在满足人们最基本的需求下，更好地帮助人们清楚地知道当前的速度、里程等物理量,更好的掌握当前运动状况。 本论文主要阐述一种具有警报功能的自行车的里程表的设计。以AT89C52单片机为核心，A44E霍尔传感器测转数，实现对自行车里程/速度的测量统计，采用24C02实现在系统掉电的时候保存里程信息，并能将自行车的里程数及速度用LED实时显示。
(With the continuous improvement of the living standard of the residents, the bicycle is no longer only a common transportation and step tool, but the first choice for people's entertainment, leisure and exercise. This provides the conditions for the birth of a bicycle speedometer. An economical speedometer can better help people know the current speed, mileage and other physical quantities, and better grasp the current sports conditions, to meet the basic needs of the people. This paper mainly describes the design of a bicycle odometer with alarm function. Taking the AT89C52 single chip as the core, the A44E Holzer sensor measured the rotation number, realized the measurement and statistics of the bicycle mileage / speed, and used 24C02 to save the mileage information when the system dropped the power, and could display the mileage and speed of the bicycle in real time with the LED.)