{"product_id":"hc-05-bluetooth-wireless-rs-232-master-slave-rf-transceiver-module","title":"HC-05 Bluetooth Wireless RS-232 Master\/Slave Transceiver Module","description":"\u003ch2\u003e📋 Overview\u003c\/h2\u003e\n\u003cp\u003eThe HC-05 is a Bluetooth 2.0 serial transceiver module that adds wireless communication to your Arduino or microcontroller projects. It works as a wireless serial (UART) bridge — anything you send over the serial connection on one end comes out the Bluetooth connection on the other end, and vice versa. No complex Bluetooth protocol knowledge is required.\u003c\/p\u003e\n\u003cp\u003eWhat makes the HC-05 especially versatile is that it can operate as either a \u003cstrong\u003emaster\u003c\/strong\u003e or a \u003cstrong\u003eslave\u003c\/strong\u003e device. Slave mode means it waits for another device (like your phone) to connect to it. Master mode means it can actively initiate a connection to another Bluetooth device. Configuration is done using simple AT commands sent over the serial connection.\u003c\/p\u003e\n\u003cblockquote\u003e\n\u003cp\u003e\u003cstrong\u003e⚠️ Important:\u003c\/strong\u003e The HC-05's \u003cstrong\u003eRX data pin is NOT 5V tolerant\u003c\/strong\u003e. You must use a voltage divider (1 kΩ + 2 kΩ) on the RX pin when connecting to a 5V Arduino. Connecting 5V directly to the RX pin can permanently damage the module. The breakout board can be powered from 3.6V to 6V (typically 5V from Arduino), but the data pins operate at 3.3V logic.\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\u003chr\u003e\n\u003ch2\u003e⭐ Key Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBluetooth 2.0 + EDR:\u003c\/strong\u003e Based on the CSR BC417 radio chip with data rates up to 3 Mbps\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaster and Slave Modes:\u003c\/strong\u003e Can initiate connections (master) or accept them (slave) — configurable via AT commands\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTransparent Serial Bridge:\u003c\/strong\u003e Acts as a wireless UART — no Bluetooth protocol knowledge required\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAT Command Configuration:\u003c\/strong\u003e Change name, password, baud rate, and role using simple serial commands\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide Power Range:\u003c\/strong\u003e 3.6V to 6V input (on-board regulator provides 3.3V to the radio chip)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow Power Consumption:\u003c\/strong\u003e ~30 mA when searching\/unpaired, ~10 mA when connected\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e10-Meter Range:\u003c\/strong\u003e Class 2 Bluetooth with built-in PCB antenna, up to 10 meters (30 feet) line of sight\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e6-Pin Breakout Board:\u003c\/strong\u003e Anti-reverse header with clearly labeled pins\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDefault Settings:\u003c\/strong\u003e Name: HC-05, Password: 1234, Baud rate: 9600 (communication) \/ 38400 (AT mode)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003e📊 Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBluetooth Version\u003c\/td\u003e\n\u003ctd\u003eBluetooth 2.0 + EDR (Enhanced Data Rate)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRadio Chip\u003c\/td\u003e\n\u003ctd\u003eCSR BC417\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency Band\u003c\/td\u003e\n\u003ctd\u003e2.4 GHz ISM band\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput Power\u003c\/td\u003e\n\u003ctd\u003e-4 to +6 dBm (Class 2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSensitivity\u003c\/td\u003e\n\u003ctd\u003e-80 dBm typical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eData Rate\u003c\/td\u003e\n\u003ctd\u003eUp to 3 Mbps (EDR), UART up to 1382400 bps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRange\u003c\/td\u003e\n\u003ctd\u003eUp to 10 meters (30 feet) line of sight\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Modes\u003c\/td\u003e\n\u003ctd\u003eMaster, Slave, or Master\/Slave (loopback)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterface\u003c\/td\u003e\n\u003ctd\u003eUART (serial TTL)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDefault Baud Rate (Communication)\u003c\/td\u003e\n\u003ctd\u003e9600 bps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDefault Baud Rate (AT Command)\u003c\/td\u003e\n\u003ctd\u003e38400 bps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDefault Name \/ Password\u003c\/td\u003e\n\u003ctd\u003eHC-05 \/ 1234\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Voltage (VCC)\u003c\/td\u003e\n\u003ctd\u003e3.6V to 6V (on-board 3.3V regulator)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLogic Level (RX\/TX)\u003c\/td\u003e\n\u003ctd\u003e3.3V (RX is NOT 5V tolerant)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent (Unpaired\/Searching)\u003c\/td\u003e\n\u003ctd\u003e~30 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent (Connected)\u003c\/td\u003e\n\u003ctd\u003e~10 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAntenna\u003c\/td\u003e\n\u003ctd\u003eBuilt-in PCB antenna\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBreakout Board Dimensions\u003c\/td\u003e\n\u003ctd\u003eApprox. 44 × 16 × 4 mm (1.73 x 0.63 x 0.16 inches) L × W × H\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003chr\u003e\n\u003ch2\u003e📌 Pinout\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003ePin\u003c\/th\u003e\n\u003cth\u003eName\u003c\/th\u003e\n\u003cth\u003eI\/O\u003c\/th\u003e\n\u003cth\u003eDescription\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003ctd\u003eEN \/ KEY\u003c\/td\u003e\n\u003ctd\u003eInput\u003c\/td\u003e\n\u003ctd\u003eHold HIGH (3.3V) during power-on to enter AT command mode. Leave unconnected for normal use.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003ctd\u003eVCC\u003c\/td\u003e\n\u003ctd\u003ePower\u003c\/td\u003e\n\u003ctd\u003ePower supply: 3.6V to 6V. Connect to Arduino 5V pin.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003ctd\u003eGND\u003c\/td\u003e\n\u003ctd\u003ePower\u003c\/td\u003e\n\u003ctd\u003eGround. Connect to Arduino GND.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003eTXD\u003c\/td\u003e\n\u003ctd\u003eOutput\u003c\/td\u003e\n\u003ctd\u003eSerial data output (3.3V). Connect to Arduino RX pin.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003ctd\u003eRXD\u003c\/td\u003e\n\u003ctd\u003eInput\u003c\/td\u003e\n\u003ctd\u003eSerial data input (3.3V). Use voltage divider from Arduino TX. NOT 5V tolerant.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003eSTATE\u003c\/td\u003e\n\u003ctd\u003eOutput\u003c\/td\u003e\n\u003ctd\u003eHIGH when connected, LOW when disconnected. Optional — often left unconnected.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003chr\u003e\n\u003ch2\u003e🔌 Wiring to Arduino UNO\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eHC-05 Pin\u003c\/th\u003e\n\u003cth\u003eArduino UNO Pin\u003c\/th\u003e\n\u003cth\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eVCC\u003c\/td\u003e\n\u003ctd\u003e5V\u003c\/td\u003e\n\u003ctd\u003ePowers the module via on-board regulator\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGND\u003c\/td\u003e\n\u003ctd\u003eGND\u003c\/td\u003e\n\u003ctd\u003eCommon ground\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTXD\u003c\/td\u003e\n\u003ctd\u003eD2 (SoftwareSerial RX)\u003c\/td\u003e\n\u003ctd\u003eHC-05 TX → Arduino RX. 3.3V output is safe for Arduino.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRXD\u003c\/td\u003e\n\u003ctd\u003eD3 (SoftwareSerial TX) via voltage divider\u003c\/td\u003e\n\u003ctd\u003e1 kΩ from D3 to RXD, 2 kΩ from RXD to GND.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEN \/ KEY\u003c\/td\u003e\n\u003ctd\u003eNot connected\u003c\/td\u003e\n\u003ctd\u003eLeave unconnected for communication mode\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSTATE\u003c\/td\u003e\n\u003ctd\u003eNot connected\u003c\/td\u003e\n\u003ctd\u003eOptional — connect to detect connection status\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003chr\u003e\n\u003ch2\u003e📦 What's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1× HC-05 Bluetooth Wireless RS-232 Master\/Slave Transceiver Module (6-pin breakout board)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eVoltage divider resistors, jumper wires, and Arduino board are not included.\u003c\/em\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003e🔌 Compatible With\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eArduino UNO, Mega, Nano, and other 5V Arduino boards (with voltage divider on RX)\u003c\/li\u003e\n\u003cli\u003eESP8266 and ESP32 boards (3.3V — no voltage divider needed)\u003c\/li\u003e\n\u003cli\u003eRaspberry Pi (3.3V — no voltage divider needed)\u003c\/li\u003e\n\u003cli\u003eAndroid phones and tablets (via Bluetooth SPP serial terminal apps)\u003c\/li\u003e\n\u003cli\u003eWindows and Linux computers with Bluetooth\u003c\/li\u003e\n\u003cli\u003eOther HC-05 or HC-06 modules (master\/slave pairing)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cblockquote\u003e\n\u003cp\u003e\u003cstrong\u003e⚠️ Not Compatible with iOS:\u003c\/strong\u003e The HC-05 uses Bluetooth Classic (SPP profile), which is not supported by iPhones or iPads for third-party apps. For iOS projects, use a BLE module such as the HM-10 or an ESP32.\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\u003chr\u003e\n\u003ch2\u003e🎯 Typical Applications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eWireless serial communication between Arduino and Android phone\u003c\/li\u003e\n\u003cli\u003eBluetooth remote control for robots, cars, and drones\u003c\/li\u003e\n\u003cli\u003eWireless data logging from sensors to a phone or computer\u003c\/li\u003e\n\u003cli\u003eBluetooth-controlled home automation (lights, relays, locks)\u003c\/li\u003e\n\u003cli\u003eWireless link between two Arduinos (master + slave pair)\u003c\/li\u003e\n\u003cli\u003eReplacing wired RS-232 serial connections with wireless\u003c\/li\u003e\n\u003cli\u003eRemote monitoring and debugging of Arduino projects\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003e🚀 Getting Started\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eWire the HC-05 to your Arduino: VCC → 5V, GND → GND, TXD → D2, RXD → D3 via voltage divider (1 kΩ + 2 kΩ)\u003c\/li\u003e\n\u003cli\u003eUpload a SoftwareSerial bridge sketch (see User Guide for complete code examples)\u003c\/li\u003e\n\u003cli\u003eOpen the Serial Monitor at 9600 baud\u003c\/li\u003e\n\u003cli\u003eOn your Android phone, go to Settings → Bluetooth and pair with \"HC-05\" (password: 1234)\u003c\/li\u003e\n\u003cli\u003eOpen a Bluetooth serial terminal app on your phone and connect to HC-05\u003c\/li\u003e\n\u003cli\u003eType messages on either end — they appear on the other end wirelessly\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cblockquote\u003e\n\u003cp\u003e\u003cstrong\u003e💡 Tip:\u003c\/strong\u003e See our complete \u003cstrong\u003eUser Guide\u003c\/strong\u003e (link below) for detailed wiring diagrams, voltage divider instructions, AT command reference, master\/slave pairing setup, three complete Arduino sketches, and troubleshooting tips.\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\u003chr\u003e\n\u003ch2\u003e⚠️ Important Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRX Pin is NOT 5V Tolerant:\u003c\/strong\u003e Always use a voltage divider (1 kΩ + 2 kΩ) when connecting the HC-05 RX pin to a 5V Arduino. Connecting 5V directly will damage the module.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot Compatible with iOS:\u003c\/strong\u003e The HC-05 uses Bluetooth Classic (SPP), which is not supported by iPhones or iPads. Use an HM-10 (BLE) or ESP32 for iOS projects.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot Bluetooth Low Energy (BLE):\u003c\/strong\u003e The HC-05 is Bluetooth 2.0 Classic. It cannot communicate with BLE-only devices.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAT Command Mode:\u003c\/strong\u003e To configure the module, EN\/KEY must be held HIGH before power is applied. AT mode uses 38400 baud. Serial Monitor must be set to \"Both NL \u0026amp; CR\" line endings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDefault Settings:\u003c\/strong\u003e Name: HC-05, Password: 1234, Baud rate: 9600 (communication), Role: Slave. Use \u003ccode\u003eAT+ORGL\u003c\/code\u003e to restore factory defaults if needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse SoftwareSerial:\u003c\/strong\u003e Don't connect the HC-05 to Arduino pins 0 and 1 (hardware serial) — these are needed for sketch uploads and the Serial Monitor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2.4 GHz Interference:\u003c\/strong\u003e The HC-05 operates in the 2.4 GHz band shared with WiFi and other Bluetooth devices. Walls and metal objects can reduce the 10-meter range.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003e📄 Documentation \u0026amp; Resources\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/learn\/hc-05-bluetooth-wireless-rs-232-master-slave-transceiver-module-user-guide\" target=\"_blank\" title=\"HC-05 Bluetooth Wireless RS-232 Master\/Slave Transceiver Module User Guide\" rel=\"noopener\"\u003eHC-05 Bluetooth Transceiver Module User Guide\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/learn\/tagged\/communication-modules\" target=\"_blank\" title=\"All Communication Module User Guides\" rel=\"noopener\"\u003eAll Communication Module User Guides\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003cp\u003e\u003cem\u003eSold and supported by\u003cspan\u003e \u003c\/span\u003e\u003ca rel=\"noopener noreferrer\" href=\"https:\/\/envistiamall.com\/\" target=\"_blank\"\u003eEnvistia Mall\u003c\/a\u003e. Ships from the USA. For wiring diagrams, setup instructions, and troubleshooting, see the User Guide. The manufacturer and Envistia LLC (dba Envistia Mall) are not responsible for any damages or losses resulting from the use of this product. Always follow proper electrical safety practices when working with electronic components. Specifications are based on manufacturer data and are subject to change without notice.\u003c\/em\u003e\u003c\/p\u003e","brand":"Envistia","offers":[{"title":"Default Title","offer_id":28453693641,"sku":"EM-COMMS-0005","price":6.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1641\/0911\/products\/hc-05-bluetooth-wireless-rs-232-master-slave-rf-transceiver-module-for-arduino-486662.jpg?v=1612603958","url":"https:\/\/envistiamall.com\/products\/hc-05-bluetooth-wireless-rs-232-master-slave-rf-transceiver-module","provider":"Envistia Mall","version":"1.0","type":"link"}