| Feature | BL12-A3 | HC-05 | HC-06 | HM-10 | |---------|---------|-------|-------|-------| | Bluetooth Classic/BLE | BLE 4.0 | Classic 2.0 | Classic 2.0 | BLE 4.0 | | Master/Slave Capable | Slave (optional master firmware) | Both | Slave only | Both | | AT Command Mode | Yes | Yes | Limited | Yes | | Default Baud Rate | 9600 | 9600 | 9600 | 9600 | | Typical Cost | ~$3–5 | ~$6–8 | ~$4–6 | ~$8–10 | | iOS/Android App Support | BLE apps | Classic SPP apps | Classic SPP apps | BLE apps |

For under $30, you get a headset that rivals Jabra or Plantronics models that cost $100. The mono design keeps one ear free to hear your own voice or office surroundings.

Once selected, you will typically hear a confirmation sound from the fixture's speakers indicating the connection is successful. Technical Characteristics Wireless Technology: Operates on the 2.4 GHz UHF radio frequency, typical for standard Bluetooth technology Standard effective distance is approximately 30 feet (10 meters) without major obstacles like thick walls. Installation: In shower systems, the module is usually housed near the LED power driver

Connect the module's to the Arduino's TX (Pin 1 or a SoftwareSerial pin).

The BL12-A3 Bluetooth module offers several advantages over other wireless modules, including: