Item specifics
Description
JDY-31 SPP-C Bluetooth to Serial Adapter Module Product Overview
The JDY-31 SPP-C is a Bluetooth to Serial (UART) adapter module designed based on the Bluetooth 3.0 SPP protocol, supporting data transparent transmission across mainstream operating system platforms including Windows, Linux, and Android. This module adopts the classic Bluetooth protocol, operates in the 2.4GHz frequency band with GFSK modulation. As a pin-compatible replacement for HC-05/HC-06 modules, the JDY-31 offers simpler operation and a more competitive price point. The module features a built-in PCB RF antenna with a maximum transmission power of 8dB and a maximum transmission distance of 30 meters. Users can flexibly modify device name, baud rate, and other parameters via AT commands for convenient and quick use. This module is widely used in Bluetooth wireless data transmission, industrial remote control and telemetry, smart home control, automotive testing equipment, and other fields, effectively replacing cumbersome serial cable connections and enabling wireless data exchange between devices.
JDY-31 SPP-C Bluetooth to Serial Adapter Module Key Features
The JDY-31 Bluetooth module is designed based on Bluetooth 3.0 SPP (Serial Port Profile), supporting the SPP serial protocol for transparent serial data transmission. It operates in the 2.4GHz to 2.48GHz unlicensed ISM bandwith GFSK modulation. The communication interface is UARTwith TTL 3.3V logic level support. Maximum transmission power is 8dBwith a maximum transmission distance of 30 meters. Built-in PCB RF antenna. Supports AT commands for modifying device name, baud rate, and other parameters. Supports continuous data transmission at 128000 baud rate without packet loss, with SPP maximum throughput of 16K bytes/s. Default Bluetooth name is JDY-31-SPP, default pairing password is 1234, and default baud rate is 9600. Module dimensions are 19.6×14.94×1.8mm (L×W×H) with a weight of only 3g. Pin definitions include STATE (connection status pin), RXD (serial input), TXD (serial output), GND (ground), VCC (power), and EN (enable pin).
JDY-31 SPP-C Bluetooth to Serial Adapter Module Applications
The JDY-31 SPP-C Bluetooth module is widely used in Bluetooth wireless data transmission, easily connecting with PC Bluetooth devices or enabling data exchange between two modules, eliminating cumbersome cable connections and directly replacing serial cables. Key applications include: Bluetooth wireless data transmission, industrial remote control and telemetry, POS systems and wireless keyboards/mice, transportation and underground positioning/alarm systems, automated data acquisition systems, wireless data transmission and banking systems, wireless data collection, smart home and industrial control, automotive testing equipment and OBDII diagnostic tools, interactive voting devices for TV stations, government streetlight energy-saving equipment, wireless LED display systems, Bluetooth joysticks and game controllers, Bluetooth printers, Bluetooth remote control toys, building automation and security access control systems, shared power banks and shared scales, and medical instruments.
JDY-31 SPP-C Bluetooth to Serial Adapter Module Key Advantages
As a perfect replacement for HC-05/HC-06 modules, the JDY-31 features pin-compatible design for direct module replacement without PCB layout modifications. AT command set is highly compatible with HC-05, with AT debugging available immediately upon power-up without additional button or pin operations. Supports data transparent transmission across Windows, Linux, and Android platformswith broad compatibility. Built-in PCB antenna with maximum transmission distance of 30 metersmeets most short-range wireless communication needs. Extremely low standby power consumption at only 4.7mA when disconnected, suitable for battery-powered portable devices. Ultra-compact size of 19.6×14.94×1.8mm with weight of only 3gfor easy integration into various compact devices. SPP maximum throughput of 16K bytes/smeets standard serial data transmission requirements. Supports AT commands for flexible configuration of device name, baud rate, pairing password, and other parameters, enabling rapid module configuration without programming. The JDY-31 is a classic Bluetooth slave modulerequiring only VCC, GND, RXD, and TXD pin connections for basic communication functionality, making it simple and easy to use.
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FAQ
1. What is the JDY-31 Bluetooth module？
The JDY-31 is a Bluetooth-to-serial slave module based on the Bluetooth 3.0 SPP protocol. It converts traditional serial communication into wireless Bluetooth transmission, directly replacing cumbersome cable connections and is widely used in short-range wireless data transmission.
2. What are the key specifications of the JDY-31 module？
Working Frequency: 2.4GHz ISM band
Bluetooth Version: V2.1+EDR / V3.0 SPP
Operating Voltage: 1.8V ~ 3.6V (3.3V recommended)
Max Transmission Power: 8dB
Max Transmission Distance: 30 meters
Default Baud Rate: 9600
Interface: UART
3. What is the difference between JDY-31 and HC-05/HC-06？
The JDY-31 is a pure slave module, while HC-05 supports both master and slave mode switching. The JDY-31 requires no complex pairing process after power-on and can be directly discovered and connected by a phone. The method to enter AT mode also differs — JDY-31 accepts AT commands directly after power-on, without requiring buttons or specific pin states like HC-05. The JDY-31 default baud rate is 9600.
4. How do I connect the JDY-31 module？
The module typically requires only 4 pins: VCC, GND, RXD, and TXD. Remember to connect crosswise: the module's TXD goes to the device's RXD, and the module's RXD goes to the device's TXD. 3.3V power supply is recommended; voltage should not exceed 3.6V.
5. What development tools support the JDY-31 module？
No dedicated tools are required. You can connect it to a PC using a USB-to-TTL module (e.g., CH340) and use a serial terminal for AT command debugging and data transmission. When connecting to microcontrollers like Arduino or STM32, direct UART communication is sufficient.
6. What is the operating temperature range of the JDY-31 module？
The operating temperature range is -40°C to +80°C.
7. What is the power consumption of the JDY-31 module？
The JDY-31 is a low-power slave module. Operating current is approximately 4.7mA when idle and 7.3mA when connected.
8. How do I interpret the LED indicator status on the JDY-31 module？
After power-on, the red LED flashes rapidly, indicating the module has entered pairable mode. The module also has a STATE pin: low level when not connected, high level when connected.
9. What applications is the JDY-31 module suitable for？
It is widely used in:
Bluetooth wireless data transmission (replacing serial cables)
Industrial remote control and telemetry
POS systems, wireless keyboards/mice
Smart home and industrial control
Wireless LED display systems
Bluetooth printers and Bluetooth game controllers
Automotive diagnostic tools (OBDII)
Building automation, security, and access control systems