The working principle of Bluetooth module mainly includes the following key steps and components:
RF transmission and reception: The Bluetooth module transmits and receives data through the built-in RF transceiver. When data needs to be sent, the Bluetooth module converts the data into wireless signals and sends it out through the antenna; when receiving wireless signals sent by other devices, the Bluetooth module converts the signals into digital data for use by other modules.
Bluetooth protocol stack: A Bluetooth protocol stack is embedded in the Bluetooth module to handle various layers of Bluetooth communication. The Bluetooth protocol stack includes the physical layer, link layer, network layer, transport layer and application layer. Different layers are responsible for different functions, such as establishing communication connections, data transmission, data encryption, etc.
BLE (Bluetooth Low Energy) technology: BLE technology was introduced from Bluetooth version 4.0, also known as Bluetooth Smart. Compared with classic Bluetooth, BLE can achieve communication while maintaining relatively low power consumption. BLE achieves low power consumption by reducing radio wake-up time, shortening connection time, and using smaller data packets.
Master-slave relationship and data transmission: In Bluetooth communication, the BLE module can act as a master or slave device. The master device is responsible for finding and initiating pairing. After the connection is established, two-way data or voice communication can be carried out between the master and slave devices. The slave device usually works in slave mode, waiting for other master devices to connect. When necessary, it can switch from slave mode to master mode and initiate calls to other devices.
Frequency hopping spread spectrum technology: Bluetooth devices use the 2.4GHz ISM band for data transmission through the built-in RF module. In order to avoid interference, Bluetooth uses frequency hopping spread spectrum technology, which quickly hops in 79 different channels, hopping 1600 times per second. This mechanism can effectively avoid interference from other wireless devices and ensure the stability of the connection.
