HC-05 Bluetooth Serial Transceiver Module – 6-Pin Dual Mode (Master/Slave) Wireless Connector with Reset Button for Arduino and ESP32

Technical Details

• Core Chipset: Based on the CSR BC04 Bluetooth technology with a built-in 2.4GHz PCB antenna.

• Transmit Power: Class 2 power level with a range of approximately 10 meters in open space.

• Default Settings: Ships with a default baud rate of 9600, 8 data bits, 1 stop bit, and no parity.

• AT Command Mode: Uses 38400 baud rate for configuration; accessible by holding the button during power-up.

• Operating Current: Draws 30-40mA during pairing and drops to approximately 8mA once a connection is established.

• Logic Level: UART pins operate at 3.3V; the module includes an on-board regulator to handle 5V VCC input.

• Sensitivity: Excellent receiver sensitivity of -80dBm for stable data transfer even at range limits.

• Modulation: Uses GFSK (Gaussian Frequency Shift Keying) for robust signal integrity.

• Frequency Band: Operates on the standard 2.4GHz ISM band.

• State Pin: High output when connected, allowing microcontrollers to monitor link status in real-time.

• EN Pin: Can be pulled low to put the module into a low-power sleep mode to save energy.

• Security: Supports simple pairing and encrypted data transmission; default PIN is usually 1234.

• Dimensions: Standard size of 28mm x 15mm x 2.35mm, fitting easily into compact project housings.

• PCB Quality: High-quality industrial-grade PCB with clear silk-screen labeling for error-free wiring.

• Environmental Tolerance: Reliable operation in temperatures ranging from -20°C to +75°C.

Prototyping and Engineering Tips from Robogears

• 9V Battery Use: Do not connect 9V directly to the module. Ensure you use the 5V regulated output from your Arduino to power the VCC pin.

• 18650 Cell: A single 18650 cell is an excellent power source. For the best stability, we suggest using a 10uF capacitor across the power pins to filter out noise.

• Resistor IC Tip: Since the RX pin is 3.3V logic, always use a voltage divider (1k and 2k resistors) when connecting to a 5V Arduino TX pin to protect the module.

• Related Products: We recommend using this with our Arduino Uno R3, Logic Level Converters, and Bluetooth Terminal Apps for smartphone testing.

Package Includes

• 1 x HC-05 6-Pin Bluetooth Module (Master/Slave).

Disclaimer Image is for illustration purpose only 2-3 lines. Always disconnect the module from the RX/TX pins of your Arduino while uploading code to prevent serial port conflicts.