HC-05 藍牙模組

Product Features:

• The core module uses the HC-05 slave module, with interfaces including VCC, GND, TXD, RXD, and KEY pins, and a Bluetooth connection status pin (STATE). It outputs low when not connected and high when connected.
• The LED indicates the Bluetooth connection status: fast blinking means no Bluetooth connection, slow blinking means entering AT mode, and double blinking means Bluetooth is connected and the port is open.
• The baseboard has a reverse polarity protection diode and a 3.3V LDO. The input voltage is 3.6~6V, current is about 30mA when not paired, and about 10mA when paired. The input voltage must not exceed 7V!
• The interface level is 3.3V, which can directly connect to various microcontrollers (51, AVR, PIC, ARM, MSP430, etc.). 5V microcontrollers can also connect directly without using MAX232 and must not pass through MAX232!
• The effective distance in open areas is 10 meters (power level is CLASS 2). Exceeding 10 meters is possible, but the connection quality is not guaranteed for that distance.
• After pairing, it works as a full-duplex serial port. There is no need to understand any Bluetooth protocols. It supports 8 data bits, 1 stop bit, and configurable parity communication formats. These are the common communication formats and other formats are not supported.
• It can enter AT command mode to set parameters and query information by pulling up pin 34.
• The module is small (3.57cm*1.52cm), produced with factory SMT to ensure quality. It is enclosed in transparent heat-shrink tubing, which is dust-proof, aesthetically pleasing, and provides some antistatic protection.
• It can switch between master and slave modes via AT commands and can connect to specified devices via AT commands.
• It supports standard baud rates from 4800bps to 1382400bps.

Product Applications:

After pairing, it can be used as a fixed baud rate serial port. Any serial device that communicates with a “fixed baud rate, 8 data bits, no parity” format can replace the original wired serial port without modifying the program. Applications include data collection, smart cars, serial printers, outdoor dot matrix screens, and more.

• Pairing with a computer: Suitable for Bluetooth serial communication between a computer and a device, used just like a serial port.
• Pairing with a mobile phone: Suitable for Bluetooth serial communication between a phone and a device, used just like a serial port.
• Pairing with a Bluetooth host: Suitable for direct Bluetooth serial communication between two devices, such as between microcontrollers or between a wired serial port and a microcontroller, used just like a serial port.

Alternative use: Baud rate conversion, as the receiving and transmitting ends can choose their respective baud rates. It can be used as a baud rate conversion device when the data volume is small.

How to Connect the Bluetooth Module to a Computer:

The following example explains how to pair it with a Bluetooth-enabled computer:

1. First, power up the Bluetooth pass-through module. The LED will start blinking. Open “My Bluetooth Places” and click “Search for devices in range.”
2. The system will search for Bluetooth devices. The default device name is “linvor” (if the name has been changed, it will display the new name, such as “jiayuanelectron”). Double-click or right-click and select “Add Bluetooth device.”
3. Enter the pairing password (default is “1234”).
4. Click “Next.” If the password is correct, the computer will establish a connection with the pass-through module. If Bluetooth serial devices have not been installed before, the system will automatically install the drivers and create a virtual serial port.
5. Click “Configure” and choose the appropriate COM port.
6. Here, you can choose COM5. This port will be the serial port for operations on the computer after connection. For example, if it is COM5, opening this port will cause the Bluetooth module’s LED to change from fast blinking to double blinking. You can then use the Bluetooth module as if it were a fixed baud rate serial port on the computer, except it is wireless.