Bluetooth Module HC-05 for Robotics

Bluetooth Module HC-05 for Robotics is a popular, robust, and cost-effective wireless communication module designed to add serial Bluetooth connectivity to microcontrollers. Based on the CSR BlueCore4-External chipset, this module supports both Master and Slave operating modes, allowing it to initiate connections with other Bluetooth devices or accept incoming pairings from smartphones, tablets, and computers. Featuring a standard 6-pin breakout layout, a built-in ceramic antenna, and transparent serial data streaming, it is the premier wireless solution for controlling Arduino and ESP32 robots, smart home appliances, and telemetry data loggers via Android mobile apps.

Features

• Dual-role capability: Configurable via AT commands as either a Master device (initiating connections) or Slave device (accepting connections)
• Built on the reliable CSR BlueCore4 Bluetooth 2.0 + EDR (Enhanced Data Rate) protocol stack
• Transparent serial data communication allowing plug-and-play wireless replacement of physical UART serial cables
• Standard 6-pin breakout interface (EN, VCC, GND, TXD, RXD, STATE) for flexible wiring and AT-mode configuration
• Onboard status LED indicators providing visual feedback for connection pairing and standby states
• Built-in ceramic antenna offering a reliable wireless communication range of up to 10 meters (30 feet) in open space
• Low power consumption operating on a standard 3.3V DC power supply with support for 5V UART logic level compatibility
• Fully compatible with standard Android Bluetooth terminal apps (e.g., Arduino Bluetooth Controller, MIT App Inventor projects)

Applications

• Wireless smartphone control for Bluetooth 2WD/4WD robotic cars, robotic arms, and rover chassis
• Wireless data logging, telemetry streaming, and remote sensor debugging for Arduino and ESP32 projects
• Custom Android app automation built via MIT App Inventor for smart home switches and appliances
• Wireless multi-machine communication and industrial serial cable replacement
• Polytechnic diploma, university engineering thesis, and Arduino STEM wireless robotics projects

Important Notes:

• VCC Voltage Warning: The HC-05 VCC pin requires 3.3V DC (though some breakout boards include an onboard 5V regulator allowing 5V input on the board's VCC pin; check your specific board layout). However, the RX data line operates strictly on 3.3V logic. If connecting to a 5V microcontroller like an Arduino Uno, use a simple voltage divider (e.g., 1k and 2k resistors) on the Arduino TX to HC-05 RX line to prevent damaging the module.
• AT Command Mode: To change configuration settings (such as Bluetooth name, pairing password/PIN, or baud rate), you must enter AT command mode by holding down the small tactile button on the module while powering it on (the LED should blink slowly at 2-second intervals).
• Default Configuration: The factory default baud rate for communication is typically 9600 or 38400 (in AT mode), and the default pairing password is usually 1234 or 0000.
• Cross Connection: Always cross your serial lines: connect the microcontroller's TX pin to the HC-05 RX pin, and the microcontroller's RX pin to the HC-05 TX pin.

Package includes

• 1 x Bluetooth Module HC-05 (Breakout Board with 6-pin header)