The Principle and Algorithm of Earthquake Alarm System Designed for Families

Combined with a 51 SCM, AT89LV55, a three-axis accelerometer, ADXL335, and a digital-to-analog conversion chip, AD7708, a seismic alarm system has been designed, which can be placed and used in residents’ homes or some public places. ADXL335 is used to measure the acceleration of three axis, X axis, Y axis and Z axis. The design, a combination of performance chip AT89LV55 and other interface functions, functioned with the relationship between seismic magnitude and acceleration, so that we can resort to the software enquiry to figure out the seismic magnitude. In addition, large variation on Z axis would trigger the alarm that earthquake is coming. The procedure has been simulated and debugged on the actual Printed Circuit Board and a summary was made. In fact, the system delivers the seismic message promptly with high accuracy and provides some additional functions such as voice prompt and calendar.