Description

HC-05 is a classic Bluetooth 2.0 serial communication module used to add wireless UART (TX/RX) communication to Arduino, ESP32, and other microcontrollers. It is widely used in robotics, smart devices, and DIY electronics for wireless control and data transfer between phone ↔ microcontroller or PC ↔ microcontroller.

🔹 Features

✅ Bluetooth 2.0 + EDR (Classic Bluetooth)
✅ Serial UART communication (TX/RX)
✅ Works with Arduino, ESP32, PIC, STM32
✅ Range up to ~10 meters
✅ Default baud rate: 9600
✅ Can work in Master or Slave mode
✅ Easy AT command configuration
✅ Compatible with Android, Windows, Linux

🔹 Pinout (6 Pins Version)

• VCC → 3.6V to 6V (usually 5V)
• GND → Ground
• TXD → Serial data output
• RXD → Serial data input (needs voltage divider for 5V boards)
• EN / KEY → AT mode control
• STATE → Connection status indicator

🔹 Specifications

• Model: HC-05
• Bluetooth Version: 2.0 + EDR
• Protocol: SPP (Serial Port Profile)
• Operating Voltage: 3.6V – 6V
• Logic Level: 3.3V (RX is not 5V tolerant)
• Current Consumption: ~30mA
• Range: up to 10 meters (open space)
• Default PIN: 1234 or 0000
• Default Baud Rate: 9600 (data mode) / 38400 (AT mode)