计步器功能可以根据计算人的运动情况来分析人体的健康状况。而人的运动情况可以通过很多特性来进行分析。与传统的机械式传感器不同，ADXL345是电容式三轴传感器，由它捕获人体运动时加速度信号，更加准确。信号通过低通滤波器滤波，由单片机内置A／D转换器对信号进行采样、A／D转换。软件采用自适应算法实现计步功能，减少误计数，更加精确。单片机STC89C52控制液晶显示计步状态，并且可以设置里程距离和每步的距离。  达到一定距离后发出报警提示，整机工作电流只有1-1.5mA，实现超低功耗。

关键字：计步器;加速度传感器;ADXL345;低功耗

Design and realization of pedometer-based microcontrollers

Abstract：Pedometer is a popular daily exercise progress monitor, can motivate people to challenge themselves, enhance physical fitness, to help lose weight. Early designs used a weighted mechanical switch detects the pace, and with a simple counter. When shaking the device, you can hear a metal ball to slide back and forth, left and right, or a pendulum swinging percussion stopper.

Pedometer function can calculate the movement of people to analyze the situation of human health. And the movement of people can be analyzed by many features. With the traditional mechanical sensors differ, ADXL345 three-axis sensor is a capacitive acceleration signal by its human motion capture, and more accurate. Signal through a low pass filter, the microcontroller built-in A / D converter for signal sampling, A / D conversion. Software uses an adaptive algorithm pedometer function, reduce error count is more accurate. STC89C52 SCM control LCD pedometer state. Machine operating current of only 1-1.5mA, ultra-low power consumption.

Key Words: pedometer; Acceleration sensor;  ADXL345;  low power consumption