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I want to calculate the RSSI value of a Bluetooth module (HC05) and from the derived RSSI value I want to calculate the distance of the surrounding devices. I'm using an Arduino Uno r3 as a controller and the Arduino IDE as a programmer.

Actually I have done the RSSI calculations with a NodeMCU device, but there also I can't convert it into a distance in meters. Please let me know the solution of this problem. The reason why I downgraded to Bluetooth from Wifi is the battery Capacity.

Also let me know about operating voltage levels of WiFi and Bluetooth and which one has better efficiency and power consumption.

dda
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Arockia Jegan
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1 Answers1

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First you have to know that only one RSSI gives you nothing about distance. Because it may vary from device to device. To calculate distance you must know "calibrated" value. For example, RSSI value measured with this device on 1 meter distance. When you do that you will have 2 RSSI values: calibrated and current. Then use this formula:

double Dist = pow(10.0, (double)(CalibratedRssi - Rssi) / 20.0);

(The formula is valid for "calibrated" RSSI measured on 1 meter distance).

Mike Petrichenko
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