- Dedicated Slave Operation: Optimized for peripheral use, ensuring rapid discovery and a stable, “locked” pairing state with master controllers.
- Transparent Data Transmission: No complex Bluetooth protocol knowledge is required; it functions exactly like a wireless RS232 cable for standard TTL serial communication.
- Type-D Industrial Stability: Features a hardware layout optimized for low-latency data throughput and reduced packet loss in electronically noisy environments.
- Wide Power Input: The onboard breakout board includes a 3.3V LDO regulator, allowing the module to be powered safely by any source between 3.6V and 6.0V DC.
- Low Operating Current: Optimized for active data transmission with a low power footprint, making it suitable for battery-powered IoT devices and handheld tools.
- Visual Status LED: Features a bright onboard LED: fast flashing indicates searching/pairing mode, while a steady light indicates a successful connection
HC-06 4pin Bluetooth Module with Button (Compatible versions Type-D )
| Bluetooth Protocol | Bluetooth V2.0 + EDR (Classic) |
|---|---|
| Operating Voltage | 3.6V – 6.0V DC |
| Operating Current | ~35mA (Pairing); < 10mA (Connected) |
| Logic Level (I/O) | 3.3V TTL (VCC is 5V compatible) |
| Communication Interface | UART (Universal Asynchronous Receiver/Transmitter) |
| Default Baud Rate | 9600 bps |
| Default Pairing PIN | 1234 |
| Frequency Band | 2.4GHz ISM Band |
| Transmission Range | ~10 Meters (Class 2) |
| Operating Temperature | -20°C to +75°C |

- Single User & Hobbyist: Smartphone-controlled DIY robotics, remote-controlled smart lighting, and wireless sensor telemetry for home weather stations.
- Business & Commercial: Wireless serial debugging for factory machinery, cable-free point-of-sale (POS) systems, and wireless diagnostic interfaces for medical or automotive tools.
No. The HC-06 uses Bluetooth Classic (2.0). Apple iOS devices only support “Bluetooth Low Energy” (BLE 4.0+) for serial data profiles. This module is fully compatible with Android, Windows, macOS, and Linux
The HC-05 can act as both a Master (initiates connections) and a Slave. The HC-06 is Slave-only, which makes it much simpler to set up for projects where you just want to connect your phone to your hardware.
While the module is unpaired (LED is flashing), you can send AT commands via a serial monitor at 9600 baud. For example: AT+NAME=MyProject or AT+PIN=5678. Note: The HC-06 typically does not require a newline (\r\n) after the command.
While the VCC pin is 5V compatible, the RX/TX pins are 3.3V logic. For long-term reliability when using a 5V Arduino, we recommend a simple voltage divider (1kΩ and 2kΩ resistors) on the RX line of the HC-06 to safely step down the 5V signal.
Ensure the LED is flashing rapidly. If the LED is steady, it is already connected to another device. Also, ensure your PC’s Bluetooth drivers are updated and support Bluetooth 2.0/Classic profiles.
Yes. All configurations changed via AT commands (Baud rate, Name, PIN) are stored in the module’s internal non-volatile Flash memory and are preserved through power cycles








