Bluetooth Module HC-05 – OverviewThe Bluetooth Module HC-05 is a compact, reliable class 2 Bluetooth serial transceiver designed for wireless communication between microcontrollers and Bluetooth-enabled devices. Ideal for Arduino, STM32, and other MCU platforms, the HC-05 enables remote control, data logging, and automation without messy wires.Key FeaturesSupports Master and Slave modes for versatile network topologiesSerial Port Profile (SPP) for transparent UART communicationBuilt-in AT command mode for configuring role, baud rate, name, and passwordBluetooth version 2.0 EDR for stable two-way data transferDefault UART baud rate: 9600 (configurable)Operating voltage: 3.3V to 6V with 3.3V TTL interfaceOnboard LED indicators for power and connection statusCompact size: approx. 27mm x 13mmTechnical SpecificationsBluetooth version: 2.0 EDROperating voltage: 3.3V to 6VInterface level: 3.3V TTLCommunication protocol: UART (default 9600 baud)Operating modes: Master and SlaveCommunication range: Up to 10 meters (line of sight)Onboard LED: Shows status and connectionDimensions: Approx. 27mm x 13mmHC-05 Connections and PinoutVCC – 3.3V to 6V supplyGND – GroundTXD – Transmit data (connect to RX of MCU)RXD – Receive data (connect to TX of MCU). Note: use a voltage divider or level shifter when connecting to 5V TX pins.KEY / EN – Pull high before power-up to enter AT command modeSTATE – Output showing connection statusQuick Wiring TipsConnect HC-05 TXD to MCU RX and HC-05 RXD to MCU TX (use level shifting if MCU is 5V)Power from a stable 3.3V to 6V supply; avoid powering from noisy sourcesPull KEY high and power cycle the module to enter AT command modeSetting Up and Configuring HC-05Use AT commands to change the module name, set Master or Slave mode, change the baud rate, and set a PIN. Common steps:Wire VCC and GND, and pull KEY high before powering to enter AT mode.Open a serial terminal at the default AT baud (usually 38400 for AT mode or 9600 for data mode depending on firmware).Send commands like AT, AT NAME=MyHC05, AT ROLE=1 (set Master), AT PSWD=1234 to configure.Always verify the module responds with OK to confirm settings.ApplicationsArduino Bluetooth projects and remote controlWireless sensor networks and data loggingHome and industrial automationRobot-to-controller communicationRemote control of electronics and smart lightingHC-05 vs HC-06 – When to Choose HC-05HC-05 supports both Master and Slave modes and offers greater configurability through AT commands. If you need two-way communication with flexible roles and advanced setup options, HC-05 is the better choice compared to HC-06.Why Buy HC-05 from Colgroad?Affordable pricing and fast delivery in Islamabad100 percent genuine components tested before shipmentTechnical support and setup tutorials for beginners and professionalsSuitable for students, engineers, and hobbyistsOrder the HC-05 Bluetooth Module TodayBring wireless connectivity to your microcontroller projects. With the HC-05 Bluetooth module you can control and monitor electronics from your phone, laptop, or other smart devices. Order now to make your project smarter and wireless.Note: Images are for illustration purposes only. Categories: Boards, Modules and Accessories, Wireless Communication Tags: bluetooth module, Bluetooth V2.0, HC-05, Remote Control, UART Interface, Wireless Communication College Road Electronics4.85 (317 Reviews)
