Generic JDY-30 / JDY-31 SPP-C Bluetooth Serial Pass-Through Module User Manual

1. Introduction

This manual provides comprehensive instructions for the Generic JDY-30 and JDY-31 SPP-C Bluetooth Serial Pass-Through Module. This module facilitates wireless serial communication, serving as a direct replacement for older Bluetooth 3.0 and 2.0 serial communication modules like the HC-05 and HC-06. It supports the Bluetooth SPP protocol, enabling high-speed data transmission for various applications.

2. Key Features

• Bluetooth V3.0 + EDR (Enhanced Data Rate)
• Bluetooth Class 2 compliance
• Integrated PCB antenna for compact design
• Supports UART (Universal Asynchronous Receiver/Transmitter) interface
• Operates on a 3.3V power supply (SMD version: 1.8V-3.6V; with baseplate: 3.6V-6V, 5V recommended)
• Operating Frequency Band: 2.4GHz - 2.48GHz (unlicensed ISM band)
• Bluetooth Specification: V2.1+EDR
• High-speed data transmission via Bluetooth SPP protocol

3. Technical Specifications

4. Pinout Diagram and Description

The JDY-30/JDY-31 module features several pins for power, data communication, and control. Understanding the pinout is crucial for proper integration.

Figure 1: Pinout diagram of the JDY-30/JDY-31 Bluetooth module, showing power input (3.6V-6V) and 3.3V logic level pins (STATE, RXD, TXD, GND, VCC, EN).

• STATE: Status indicator pin.
• RXD: Receive Data pin (connects to TXD of host microcontroller).
• TXD: Transmit Data pin (connects to RXD of host microcontroller).
• GND: Ground connection.
• VCC: Power supply input (3.6V-6V for modules with baseplate, 1.8V-3.6V for SMD).
• EN: Enable pin.

5. Setup and Installation

Follow these steps to set up your JDY-30/JDY-31 Bluetooth module for serial communication.

1. Power Supply: Connect the VCC pin to a stable power source within the specified voltage range (3.6V-6V for modules with baseplate, 5V recommended). Ensure GND is connected to the system's ground.
2. UART Connection:
   • Connect the module's TXD pin to the host microcontroller's RXD pin.
   • Connect the module's RXD pin to the host microcontroller's TXD pin.
   • Note: Ensure voltage level compatibility. The module's logic level is 3.3V. If your microcontroller operates at 5V, a logic level converter may be required for the RXD/TXD lines to prevent damage.
3. Enable Pin (EN): The EN pin can be used to enable or disable the module. Typically, it is pulled high for operation. Refer to specific application requirements for its use.
4. Initial Configuration: The module usually operates in a default pass-through mode. Advanced configurations (e.g., changing baud rate, device name, pairing password) can often be done via AT commands sent through the UART interface. Consult the JDY-30/JDY-31 AT command set documentation for details.

Figure 2: Top view of the JDY-30/JDY-31 Bluetooth module, showing the integrated PCB antenna and main components.

6. Operating Instructions

Once the module is correctly wired and powered, it can be used for wireless serial communication.

1. Power On: Apply power to the VCC and GND pins. The module's status LED (if present) should indicate its operational state (e.g., blinking for discoverable, solid for connected).
2. Pairing:
   • On your host device (e.g., smartphone, computer, another Bluetooth module), search for Bluetooth devices.
   • The JDY-30/JDY-31 module will typically appear with a default name (e.g., "JDY-30" or "JDY-31").
   • Initiate pairing. If prompted for a password, the default is usually "1234" or "0000".
   • Upon successful pairing, the module's status LED may change to a solid state.
3. Serial Data Transmission:
   • Once paired, a virtual serial port (SPP profile) will be established.
   • Any data sent to the module's RXD pin via UART will be transmitted wirelessly to the paired device.
   • Conversely, any data received wirelessly from the paired device will be output through the module's TXD pin via UART.
   • Ensure the baud rate of your host microcontroller's UART matches the module's configured baud rate (default is often 9600 or 115200 bps).

Figure 3: Top and bottom views of the JDY-30/JDY-31 Bluetooth module, illustrating its compact design and pin headers.

7. Applications

The JDY-30/JDY-31 module is versatile and suitable for a wide range of wireless serial communication projects, including:

• Bluetooth printers
• Bluetooth POS (Point of Sale) machines
• Intelligent home control systems
• General Bluetooth wireless data transmission between microcontrollers and other devices
• Replacement for older HC-05 and HC-06 modules in existing projects

8. Troubleshooting

If you encounter issues with your JDY-30/JDY-31 module, consider the following common problems and solutions:

• Module not powering on:
  • Verify VCC and GND connections.
  • Ensure the input voltage is within the specified range (3.6V-6V for baseplate version).
• Cannot find module during Bluetooth scan:
  • Ensure the module is powered on and its status LED is blinking (indicating discoverable mode).
  • Check the distance between the module and the scanning device.
  • Confirm the EN pin is correctly configured (usually pulled high).
• No data transmission or corrupted data:
  • Verify TXD and RXD connections are crossed correctly (module TXD to host RXD, module RXD to host TXD).
  • Ensure the baud rate of the module and the host microcontroller are identical.
  • Check for logic level compatibility. If the host is 5V, use a logic level converter for the data lines.
  • Confirm successful Bluetooth pairing and connection.
• Pairing issues (incorrect password):
  • The default pairing password is typically "1234" or "0000".
  • If the password was changed via AT commands, use the new password.

9. Warranty and Support

Warranty information for Generic products is typically provided by the seller at the point of purchase. Please refer to your purchase documentation or contact the seller directly for details regarding warranty coverage and technical support.

For additional technical resources, including detailed AT command sets and application notes, search for "JDY-30 manual download" or "JDY-31 manual download" online. Community forums and online electronics resources may also provide valuable support.