A Bluetooth shield is an electronic expansion board designed to connect wirelessly to an Arduino microcontroller using Bluetooth technology.
Essentially, a Bluetooth Shield allows your Arduino to create a wireless serial connection with other Bluetooth-enabled devices, such as a computer or smartphone. This connection is primarily used to send and receive data and commands between the Arduino and the connected device wirelessly.
Key Functionality
The primary function of a Bluetooth shield, as highlighted by the reference, is to provide wireless communication capabilities to an Arduino board.
- Wireless Serial Communication: It acts as a bridge, translating serial data from the Arduino into Bluetooth signals and vice versa. This eliminates the need for physical wires for certain communication tasks.
- Data and Command Exchange: Users can send data (like sensor readings) from the Arduino to a computer or send commands to the Arduino from a computer or app to control its behavior.
Customization and Configuration
Bluetooth shields are not just fixed communication devices; they offer flexibility:
- AT Commands: The shield can be reconfigured using AT commands. These are special text-based commands used to set parameters like the shield's name, password, baud rate, and operating mode (master or slave).
- Firmware Reflashing: For more advanced changes, the firmware can be reflashed to change its features. This allows for updates or changes to the core functionality of the Bluetooth module on the shield.
Default Behavior
Out of the box, a typical Bluetooth shield often comes with a default setup:
- Slave Device: By default, the shield acts as a slave device. This means it waits for another Bluetooth device (a master) to initiate a connection.
- Serial Link: It provides a serial link interface, connecting to the Arduino's serial communication pins (RX/TX).
By providing this wireless serial link, the Bluetooth shield significantly expands the possibilities for Arduino projects, enabling remote control, data logging, and inter-device communication without cables.
