Calculating Tx Power Level in CoreBluetooth iOS

Question

The page on this url shows that

The value of the characteristic is a signed 8 bit integer that has a fixed point exponent of 0.

Showing the Examples: The value 0x12 is interpreted as +18dBm The value 0xED is interpreted as -18dBm

How to calculate 0xED and get result as -18dBm?

Answer 1

This required simple conversion of hexadecimal to decimal values.

0xED-255=237-255=-18

0x12=18

There is nothing more to it.