Evothings

Hello, I am trying to calculate the distace in meters using the txPower and RSSI. After some searching I have found a formulas using these values, but there I have to use txPower that indicates the signal strength in 1 meter.

I wanted to use your https://www.npmjs.com/package/cordova-plugin-eddystone#plugin-implementation-details

but according to your plugin the value

{number} txPower - A signed integer, the signal strength in decibels, factory-measured at a range of 0 meters.

Please could you provide me a mathematical formula, for transforming the 0 meter txPower to 1 meter txPower. Thank you!

Hi,

I see the problem, commonly used beacon distance calculation formulas use txPower at 1 meters, while the Eddystone specification uses txPower at 0 meters. Found a note in the Eddystone specification indicating that it should work to subtract 41 from the reported txPower value at 0 meters:

Note to developers: the best way to determine the precise value to put into this field is to measure the actual output of your beacon from 1 meter away and then add 41dBm to that. 41dBm is the signal loss that occurs over 1 meter.

https://github.com/google/eddystone/tre ... ower-level

Let me know how it goes!

Best regards, Mikael

Does the power hence distance calculation change with battery life so as the battery on the beacon runs down the power and distances will be less or does the hardware somehow accommodate this