HC-05 Bluetooth Module

The HC-05 Bluetooth module is a popular and widely used wireless communication module for microcontroller-based projects, such as Arduino, Raspberry Pi, and other embedded systems. It's designed to facilitate wireless communication over short distances typically within a range of about 10 meters using Bluetooth technology (Bluetooth 2.0).

Here’s a quick overview of the HC-05 Bluetooth module:

Key Features:

1. Bluetooth Version: Bluetooth 2.0 + EDR (Enhanced Data Rate).
2. Range: Typically 10 meters (though it can be less in certain conditions).
3. Communication Interface: Serial communication (UART) through TX (Transmit) and RX (Receive) pins.
4. Voltage: Operates on 3.3V to 5V, with 3.3V logic levels for communication.
5. Master/Slave Mode: Can be configured to either master or slave mode for communication with other Bluetooth devices.
6. Data Transfer Speed: Typically 3 Mbps, though actual speeds depend on the connection and environment.
7. Pairing and Communication: You can pair it with other Bluetooth-enabled devices (such as phones, computers, or other Bluetooth modules) for sending and receiving data.

Common Applications:

• Wireless Communication: Used in wireless data transmission between microcontrollers (e.g., Arduino) and smartphones, computers, or other Bluetooth-enabled devices.
• Remote Control: For controlling robots or appliances wirelessly using a smartphone or computer.
• Wireless Data Transfer: Sending sensor data wirelessly to a smartphone or server.
• Home Automation: Controlling home appliances remotely using Bluetooth-enabled devices.

Wiring HC-05 to Arduino:

• HC-05 VCC → Arduino 5V
• HC-05 GND → Arduino GND
• HC-05 TX → Arduino RX (Pin 0)
• HC-05 RX → Arduino TX (Pin 1) (Note: If using an Arduino with 5V logic, you may need a voltage divider or a level shifter to reduce the 5V signal from Arduino TX to the HC-05 RX pin, which operates at 3.3V.)

Basic Code for Communication (Arduino Example):

#include <SoftwareSerial.h>

// Create software serial port
SoftwareSerial BTSerial(10, 11); // RX, TX pins

void setup() {
  // Start serial communication
  Serial.begin(9600);
  BTSerial.begin(9600);  // HC-05 default baud rate

  Serial.println("Bluetooth communication started!");
}

void loop() {
  // Read data from Bluetooth and send to Serial Monitor
  if (BTSerial.available()) {
    char receivedChar = BTSerial.read();
    Serial.print(receivedChar);
  }

  // Read data from Serial Monitor and send to Bluetooth
  if (Serial.available()) {
    char inputChar = Serial.read();
    BTSerial.print(inputChar);
  }
}

Configuration (AT Commands):

You can configure the HC-05 module using AT commands. This allows you to change its name, pairing password, and other settings. To enter AT mode, the HC-05 must be powered on and connected to a serial interface, then you can use a serial terminal to send commands.

Common AT Commands:

• Check if in AT mode: Type AT and the module should respond with OK.
• Change Bluetooth Name: AT+NAME=New Name
• Change Baud Rate: AT+BAUD8 (For 9600 baud)
• Set Password: AT+PSWD=1234

Origin: China

Brand: Generic