android ble 测算距离,Android——蓝牙利用RSSI进行距离测算

算法：

/**

* 功能：根据rssi计算距离

* Created by liuhuichao on 2017/1/17.

*/

public class RssiUtil {

//A和n的值，需要根据实际环境进行检测得出

private static final double A_Value=50;/**A - 发射端和接收端相隔1米时的信号强度*/

private static final double n_Value=2.5;/** n - 环境衰减因子*/

/**

* 根据Rssi获得返回的距离,返回数据单位为m

* @param rssi

* @return

*/

public static double getDistance(int rssi){

int iRssi = Math.abs(rssi);

double power = (iRssi-A_Value)/(10*n_Value);

return Math.pow(10,power);

}

}

扫描蓝牙过程中获得信号强度：

/*监听扫描过程中的变化*/

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {

@Override

public void onReceive(Context context, Intent intent) {

String action = intent.getAction();

// When discovery finds a device

if (BluetoothDevice.ACTION_FOUND