# Bluetooth module HC-05, original

> Original HC-05 Bluetooth module for wireless serial communication with Arduino and other development boards. Operates in Master or Slave mode, USART TTL communication, configurable via AT Command Mode. Default baud rate 9600 bps, supply voltage 3.6-6V, RX pin logic voltage 3.3VDC, current consumption 30mA. Uses the original HC-05 chip, firmware 4.0-20190728, IEEE 802.15.1, FHSS.

- Page: https://sigmanortec.ro/en/bluetooth-module-hc-05-original
- Price: 50.82 RON
- Availability: In stock; 1-2 zile
- Reference: 9482 · EAN: 5945690412205
- Category: Mechatronics and IoT > Sensors and Modules > Bluetooth Modules
- Package (shipping data): 0.003 kg
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 04:50 (Europe/Bucharest)

## Description

Original HC-05 Bluetooth module for wireless serial communication with Arduino and other development boards, works in Master or Slave mode for connections between two microcontrollers or with the phone and PC. Offers stable connection via USART TTL, configurable settings in AT Command Mode and fast transmission at 9600 bps by default, 3.6-6V.
hc-05 bluetooth module, compatible with Arduino and other development boards. This module is used together with development boards for serial communication via Bluetooth. It can be used both as a Master and as a Slave.
This product uses the original HC-05 integrated which offers better stability compared to the compatible version.
With two modules, wireless communication can be achieved between two microcontrollers such as Arduino or between a microcontroller and a Bluetooth device such as a phone or a computer.
Communication is carried out via USART at a baud rate of 9600. The data transfer capacity does not extend to music files or photos.
Important: The RX pin from the Arduino works with both 5V and 3.3V logic voltage. The RX pin from the HC-05 module does NOT tolerate the 5V logic voltage. Use a level converter or voltage divider with 1k and 2k resistors. Higher value resistors will prevent fast data transmission.
* in the example above, a voltage divider consisting of 2 resistors is used to protect the RX pin
The module operates in two modes:
Data mode: can receive and send data between Bluetooth devices
AT Command mode: in this mode you can change the module settings such as Baud Rate, Name, Password, etc...
Specifications:
Supply voltage: 3.6 - 6V
RX pin logic voltage: 3.3VDC
Operating consumption: 30mA
Firmware version: 4.0-20190728
Communication: USART serial and TTL compatible
IEEE 802.15.1
FHSS
Bluetooth name: HC-05
Default password: 1234 or 0000
Default mode: Data Mode
Baud Rate Data Mode: 9600, 8, N, 1
Baud Rate Command Mode: 38400, 8, N, 1
Default firmware: LINVOR
Baud rate supported: 9600, 19200, 38400, 57600, 115200, 230400, 460800
Pins:
Enable/Key: Used to switch between Command Mode and Data Mode
VCC: 5V power supply
GND: Ground
TX: Pin that transmits serial data. It is connected to the RX pin of the Microcontroller
RX: Pin that receives serial data. It is connected to the TX pin of the Microcontroller
State: Pin connected to the integrated LED for displaying the status of the module
Using Pin Key:
Together with Arduino, the module can be connected to other digital pins by using SoftwareSerial . In the case of connecting the module directly to the RX and TX pins of the development board, before being able to upload a code to the board, these pins will have to be disconnected, otherwise the Arduino IDE will return an error in the upload.
Useful Links:
List of AT orders: Click here