BLE Identifier Terminology

There is some terminology for BLE devices that needs to be understood if you are going beyond the most basic configurations. If this guide were to be encyclopedic then it would run to hundreds of pages. Instead, here is a very quick run-down:

MAC Address: all BLE devices have a unique or pseudo-unique address called its MAC address. MAC stands for Media Access Control and is a six byte number. This number is often printed on the device or its packaging but is not always.There are often other numbers but unless it is expressed in the format 11:22:33:44:55:66 or clearly labelled as "MAC" it is probably some other number.

Serial Number: BLE devices also have a serial number. This is normally more prominently displayed (again, not always). If you can see the serial number then this is often the easiest way to ensure a connection is to the device you require.

UUID: This is the Universally Unique IDentifier that is declared by the Bluetooth consortium to represent the BLE device's basic type, such as heart rate or muscle oxygenation devices, using a UUID for ensuring a connection means the Pilot will try to connect to any device of that type. The Pilot device can only connect to UUIDs that are part of the BLE sensor config item.

BLE Link Terminology

Central: This is a BLE device that scans for other "peripheral" devices. The Pilot normally operates as a Central looking for wearable peripherals etc. but also acts as a peripheral when a PC is used to download a new config etc.

Peripheral: normally broadcast their data at all times or, at least, advertise their services at all times waiting for a central to connect. Most wearables operate as peripherals.

BLE Connection Terminology

Passive/Listen: as a central the Pilot listens for remote devices sending advertising packets. No attempt is made to communicate with the other device and this is often a good mode to collect simple data.

Connect: This means the Pilot will actively communicate with a found device and for a connection and therefore get all the available data.

Pairing: This uses encryption but requires negotiation by devices and, in our experience, is not as widely supported by low-end wearables. There is also the issue that the Pilot's normal deployment requires things to "just work" and pairing can force users to have to "acknowledge" pairing attempts which is often impossible in our normal use cases (motorsport etc).

Bonding: The most elaborate level sees the devices "bonded" to each other so no other device can listen in. It can only be done after pairing.