The HC-05 Bluetooth Module is the most versatile wireless communication tool for Arduino and DIY electronics. At Electrapac, we recommend the HC-05 over the HC-06 because of its "Master/Slave" capability, allowing your projects not just to receive data, but to actively seek out and connect to other Bluetooth devices.

Product Overview

The HC-05 is a class 2 Bluetooth module designed for transparent wireless serial communication. Once paired, it acts like a "wireless wire"—whatever data you send into the RX pin on one end comes out of the TX pin on the other. Because it can act as both a Master (initiator) and a Slave (receiver), you can use it to connect an Arduino to a smartphone, or connect two Arduinos directly to each other.

Key Features for Electrapac Customers

• Master & Slave Modes: Unlike the HC-06 (Slave only), the HC-05 can be configured to search for and connect to other Bluetooth modules, making it ideal for autonomous robot-to-robot communication.

• Easy Configuration: Features a dedicated "EN" (Enable) or "Button" pin to enter AT Command Mode, where you can change the device name, pairing password (default 1234), and baud rate.

• 6-Pin Breakout Board: Includes State and EN pins. The State pin helps your microcontroller know if the Bluetooth connection is currently active.

• Wide Compatibility: Works seamlessly with Android smartphones, laptops, and any microcontroller with a UART (Serial) interface (Arduino, PIC, STM32, Raspberry Pi).

• On-board Status LED: The flashing LED indicates the current mode (Fast flash: searching, Slow flash: AT mode, Double flash: paired).

Critical Connection Tip

To protect your module from damage when using an Arduino from www.electrapac.com:

Voltage Level Warning: While the module can be powered by 5V, the RXD pin uses 3.3V logic. When connecting an Arduino's 5V TX pin to the HC-05 RX pin, you should use a simple Voltage Divider (two resistors) to drop the signal to 3.3V to prevent burning out the chip.

Primary Applications

• Wireless Robots: Control your robot car using a custom Android app or a Bluetooth joystick.

• Remote Data Logging: Send sensor data from a remote station wirelessly to your PC for graphing.

• Home Automation: Switch lights or appliances on/off via your phone.

• Wireless Debugging: Monitor your Arduino's Serial Monitor without being tethered to a USB cable.

Why Shop at Electrapac?

We source the HC-05 with the full 6-pin interface to ensure you have complete control over the module's state. At www.electrapac.com, we provide the wireless modules that give your projects the freedom to move and communicate without limits.