Bluetooth HC-06 Wireless Transceiver Serial Module

Features:

• Serial communication: Simple serial interface with baud rate adjustable from 9600 to 115200 bps.
• Slave mode only: Supports Bluetooth SPP (Serial Port Profile) in slave mode.
• AT command control: Configurable using AT commands.
• Power supply: Operates from 3.6V to 6V, ideal for battery-powered applications.
• 4-pin design: Compact and easily connectable to microcontrollers.
• Affordable: Cost-effective Bluetooth connectivity solution.

Principle of Work:

The module uses Bluetooth technology to enable short-range wireless communication. A built-in microcontroller handles serial communication with the host (e.g., Arduino). It is configured via AT commands. After powering up, it waits for a master device to connect. Once paired, it sends and receives serial data over Bluetooth using the SPP protocol.

Pinout of the Module:

• Vcc: Connect to +5V (acceptable range: 4.0V–6.0V).
• GND: Connect to the GND of the microcontroller.
• TXD: Connect to the RX pin of the microcontroller.
• RXD: Connect to the TX pin of the microcontroller.

Note: RX and TX pins should be cross-connected (MCU RX ↔ Module TX and vice versa).

Applications:

• Wireless communication between microcontrollers and computers
• Remote control systems (via smartphone or tablet)
• Wireless sensor networks for monitoring and automation
• Robotics projects with wireless control
• Data logging and remote monitoring systems

Circuit:

1. Connect LED anode to Arduino pin 13
2. Connect LED cathode to 220Ω resistor
3. Connect the other end of the resistor to Arduino GND
4. HC-06 TX → Arduino RX
5. HC-06 RX → Arduino TX
6. HC-06 VCC → Arduino 3.3V
7. HC-06 GND → Arduino GND

Library:

No library required.

Code:

void setup() {
  pinMode(13, OUTPUT);          // Set digital pin 13 as output
  Serial.begin(9600);           // Begin serial communication
}

void loop() {
  if (Serial.available() > 0) {
    char data = Serial.read();  // Read incoming character
    if (data == '1') {
      digitalWrite(13, HIGH);   // Turn on LED
    } else if (data == '0') {
      digitalWrite(13, LOW);    // Turn off LED
    }
  }
}

This code allows Bluetooth control of an LED using a mobile app or PC serial terminal. Sending '1' turns the LED on, and '0' turns it off.

Technical Details:

• Bluetooth Version: Bluetooth 2.0, compatible with most devices
• Operating Voltage: 3.3V DC
• Serial Interface: RX/TX pins, default 9600 baud (configurable)
• Bluetooth Profile: SPP (Serial Port Profile)
• Pin Configuration: VCC, GND, RX, TX
• Range: Up to 10 meters (unobstructed)

Resources:

• Tutorials and example projects (not linked here)

Comparisons with HC-05:

• Pin Configuration: HC-06 (4 pins), HC-05 (6 pins with extra KEY and STATE)
• Master/Slave Role: HC-06 is slave-only; HC-05 supports master and slave roles
• Baud Rate: HC-06 default 9600, configurable; HC-05 supports 2400–115200 bps
• Power Consumption: HC-06 is low-power; HC-05 slightly higher