Bluetooth Low energy Chat Application Series #1
Overview of Chat application -
1. How Bluetooth Low energy device works: https://medium.com/@tgunix/bluetooth-low-energy-chat-application-series-1-f09c16d35b4a
2. Setting up Gatt Server: https://medium.com/@tgunix/bluetooth-low-energy-chat-application-series-2-75e1208179ae
3. Setting up Gatt Client : https://medium.com/@tgunix/bluetooth-low-energy-chat-application-series-3-e1940622ad90
4. Sending Data over Bluetooth Low energy network
5. Some common errors and how to resolve them(Do check this if you are getting some weird error)
Post 1: How Bluetooth Low energy device works in general
Key components
Ble : Bluetooth Low energy device
GATT : Defines protocol(set of rules) on how data should be exchanged
GATT Server : Provides functionality to create Services and broadcast itself so other Gatt Client can connect to it. (can be slightly confusing, I know but don’t worry, this will be cleared later). Treat it as a web server.
Gatt Client : It is responsible for scanning nearby GATT Server, connecting to it and exchanging data(in terms of Characteristics).
Service : A service is a collection of characteristics. For example, you could have a service called “Heart Rate Monitor” that includes characteristics such as “heart rate measurement.”
Characteristics : It contains a value and a list of descriptors. We will be exchanging characteristics as messages
Descriptors : It contains a value and generally it is used as attributes of a characteristics
UUID : Just a unique identifier, on how to uniquely identify a Service or a characteristics or a descriptor.
For exchanging data over http network, we need two devices one will act as a server and another will act as client. Eg — that’s how website work
This same thing applies in Ble network, we need two devices one will act as a Gatt server and another will act as Gatt client for exchanging of data.
And a device can be both Gatt Server and Gatt client.
There are still some concepts left, I will teach them when they are used.
For Android chat application, we will have two devices and they both will act as a Gatt Server and Gatt Client.
Reference — https://developer.android.com/guide/topics/connectivity/bluetooth-le
https://www.bignerdranch.com/blog/bluetooth-low-energy-part-1/
