System.Bluetooth.Components.TBluetoothLE.RssiToDistance

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Object Pascal

function RssiToDistance(ARssi, ATxPower: Integer; ASignalPropagationConst: Single): Double;

C++

double __fastcall RssiToDistance(int ARssi, int ATxPower, float ASignalPropagationConst);

Properties

Type Visibility Source Unit Parent
function public
System.Bluetooth.Components.pas
System.Bluetooth.Components.hpp
System.Bluetooth.Components TBluetoothLE

Description

Accepts as parameters <ARssi> (received signal strength indication in dBm), <ATxPower> (signal strength at 1m distance in dBm) and a constant <ASignalPropagationConst>. Returns an approximation of the distance to a device in meters.

The parameters needed to call this function are stored in the AdvertisedData property of the device.

Distance formula taken from: IEEE Xplore library paper: RSSI-Based Real-Time User Location Tracking System for Indoor and Outdoor Environments (DOI: 10.1109/ICCIT.2007.253, pages 1213-1218).

The formula for RSSI is RSSI = -(10*n*log10(d) + A).

Platform Support

This function is not supported on Windows.

See Also