Change Bluetooth Advertisement Name of SHA/STH

[sanssecours]

Currently we use the last 3 bytes of the MAC address as identifier (e.g. 01:de:81). This part of the address should be unique for a certain OUI (Organizationally Unique Identifier). However, according to the official OUI list, Silicon Laboratories reserved at least 12 OUIs. This means we have to use another identifier to uniquely identify a certain sensory tool holder (STH) or sensory holder assembly (SHA). Since we can only use 8 characters for the name, we decided to store the 6 bytes of the MAC address in Base64 format. The code below shows an example, on how to do that.

from base64 import b64encode

mac = [0x08, 0x6b, 0xd7, 0x01, 0xde, 0x81]
mac_text = ":".join([f"{byte:02x}" for byte in mac])
print(f"MAC: {mac_text}")
name = b64encode(bytes([0x08, 0x6b, 0xd7, 0x01, 0xde, 0x81])).decode()
print(f"Name (Base64): {name}")

This code converts the MAC address 08:6b:d7:01:de:81 into the name CGvXAd6B. We can always convert this name, back into a more readable MAC address, using the code below.

from base64 import b64decode

mac = list(b64decode('CGvXAd6B'))
print(":".join([f"{byte:02x}" for byte in mac]))