With the development of society, the advances in technology and the improvement of people's living standards, bicycles have become a very popular method of exercise. A cyclocomputer, which can be used to count the speed and distance, is one of must useful accessories. In the early time, cyclocomputers are mechanical equipments which are not that reliable. Today, electronic production of cyclocomputers as a low failure rate, high reliability and easy maintenance, which is widely used.
     Our cyclocomputer which can measure speed and distance.It use a Hall elements to transform the round count into pulse, which can be read by the SCM. The distance is the count number multiple by the wheel circumference, and the distance is divided by interval time to get the speed. The display switch between distance and speed is realized by a button.