Bluetooth Low Energy (BLE) is a wireless communication protocol designed for short-range communicati
Bluetooth Low Energy (BLE) is a wireless communication protocol designed for short-range communication between devices. Here's a simplified overview of how BLE works:
Roles:
Peripheral: The device that provides data or services.
Central: The device that consumes data or services from the peripheral.
Advertising:
The peripheral broadcasts advertising packets containing information about its services.
The central scans for these advertising packets to discover nearby peripherals.
Connection:
Once a central device decides to connect to a peripheral, it sends a connection request.
If the peripheral accepts, a connection is established.
Services and Characteristics:
BLE organizes data into services and characteristics.
Service: A collection of related data or functions.
Characteristic: A specific piece of data or a function within a service.
Attributes:
Characteristics have properties (read, write, notify, etc.) and a value.
Descriptors provide additional information about characteristics.
GATT (Generic Attribute Profile):
Defines the way that two BLE devices transfer data back and forth.
Governed by the roles of client (initiates requests) and server (responds to requests).
Connection States:
BLE operates in connection-oriented states, such as advertising, connected, and disconnected.
Operations:
Read: Retrieve the value of a characteristic.
Write: Set the value of a characteristic.
Notify/Indicate: Allow a server to send updates to a client when a characteristic's value changes.
Security:
BLE supports security features like pairing and encryption to protect communication.
When programming with ESP32 and BLE, you typically define services and characteristics, set up advertising, handle connections, and manage data exchange using the GATT protocol.
Understanding the specifics of the ESP32's BLE API and the Bluetooth standard will help you effectively implement BLE functionality in your projects.
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