中文说明：RSSI强度值采集例子，每隔一段距离采集一段RSSI值，从matlab中绘制折线图，并由最小二乘法分析你合成曲线
English Description：
RSSI strength value acquisition example, collect a section of RSSI value every other distance, draw line graph from MATLAB, and analyze your composite curve by least square method