The HC-05 Bluetooth Module with TTL Output is a widely used Bluetooth-to-Serial TTL module designed to enable wireless master or slave serial communication for embedded projects.
The HC-05 Bluetooth Module with TTL Output is a widely used Bluetooth-to-Serial TTL module designed to enable wireless master or slave serial communication for embedded projects. Built around the Cambridge Silicon Radio (CSR) BC417 Bluetooth chip, this module supports the Bluetooth 2.0 + EDR (Enhanced Data Rate) specification with Serial Port Profile (SPP), allowing microcontrollers to communicate wirelessly with laptops, smartphones, tablets, and other Bluetooth devices.
This enhanced breakout board features an onboard tactile button connected to the KEY / ENABLE pin, making it effortless to enter AT command mode for configuring baud rates, pairing passwords, device names, and master/slave roles without requiring complex external pull-up wiring. The module includes an onboard 3.3V voltage regulator, enabling safe operation from 3.6V to 6V DC power inputs while exposing 3.3V logic UART pins (TXD, RXD, STATE, EN).
Onboard status LEDs provide instant visual indication of pairing status, connection state, and AT mode configuration. The HC-05 is widely used in wireless robotics, remote telemetry, industrial wireless control, and smartphone-controlled automation. It features standard 2.54mm pitch breakout header pins that are fully compatible with Arduino, ESP32, ESP8266, Raspberry Pi, STM32, PIC, and general DIY electronics.
| Core Controller Chip | CSR BC417 Bluetooth 2.0 + EDR Transceiver |
|---|---|
| Wireless Protocol | Bluetooth Specification v2.0 + EDR with Serial Port Profile (SPP) |
| Operating Mode | Configurable Master / Slave roles (Factory default: Slave) |
| Operating Voltage | 3.6V to 6.0V DC (Onboard 3.3V LDO regulator) |
| Signal Logic Voltage | 3.3V TTL (Requires voltage divider/level shifter for 5V TXD line) |
| Integrated Onboard Button | Dedicated key button for entering AT command mode easily |
| Frequency Band | 2.4GHz ISM Band with GFSK modulation |
| Coverage Range | Up to 10 meters (Class 2 operation, open field) |
| Interface Pinout | 6-Pin Breakout (STATE, RXD, TXD, GND, VCC, EN) |
| Default Serial Settings | Baud rate 9600, 8 Data bits, 1 Stop bit, No Parity (AT Mode Default: 38400) |
What is the operating voltage?
3.6V to 6.0V DC (Onboard 3.3V LDO regulator).
Which interface does it use?
Bluetooth Specification v2.0 + EDR with Serial Port Profile (SPP).
Is it compatible with Arduino and ESP32?
Yes. It works with Arduino, ESP32, ESP8266, Raspberry Pi projects.
Can I buy the HC-05 Bluetooth Module with TTL Output in Kanpur?
Yes – buy online with delivery across India, or pick it up from the iTechBuilders store, Damodar Nagar, Kanpur.
