1. Introduction
The JDY-28M Bluetooth module is a versatile wireless communication module supporting Bluetooth Low Energy (BLE) 5.2 protocol. It features a master-slave integrated design and offers multiple configuration modes, including BLE master-slave transmission, MESH transmission, MESH command mode, car key mode, and switch panel mode. This module is designed for transparent data transmission, offering enhanced stability and anti-interference capabilities.
The JDY-28M is available in two main variants: one with an onboard PCB antenna and another with an IPEX connector for an external antenna. The choice of antenna type allows for flexibility in various application scenarios.
2. Technical Specifications
The following table details the technical specifications of the JDY-28M module:
| Parameter | Specification |
|---|---|
| Type | Module |
| Working Voltage | 2.0-3.6V |
| Working Temperature | -40 to 85℃ |
| Maximum Transmission Power | +9dbm |
| Communication Distance | 150m |
| Bluetooth Version | BLE 5.2 |
| Antenna Type | PCB board-mounted antenna (or External Antenna via IPEX) |
| Antenna Gain | -3dbi |
| Receiving Sensitivity | -96dbm |
| SMT Soldering Temperature | <260℃ |
| Communication Interface | UART |
| Module Size | 20mm x 15mm x 1.5mm (JDY-28M) |
| Communication Speed (Machine to APP) | 20K(Byte/s) |
| MESH Communication Speed | 1K(Byte/s) |
| Average Current (Non-MESH wake-up) | Around 1mA |
| Average Current (Non-MESH slave broadcast sleep) | <200uA |
| Average Current (MESH active communication) | Around 8mA |
| Average Current (MESH sleep) | 1uA |
| Deep Sleep Mode Current | 1uA |
| Package | SMD |
| Customization | Yes |
| Dissipation Power | 0 |
| Application | Computer |
| Condition | New |
Module Dimensions and Weight
The JDY-28M module has compact dimensions suitable for various embedded applications. The dimensions are approximately 20mm x 15mm x 1.5mm. The weight varies slightly depending on the antenna configuration:
- Onboard Antenna Version: Approximately 0.50g
- External Antenna (IPEX) Version: Approximately 0.56g
3. Setup and Pin Definition
Pin Layout
The JDY-28M module features a 24-pin interface. Understanding the pin definitions is crucial for proper integration and operation.
| Pin No. | Pin Name | Description |
|---|---|---|
| 1 | VCC | Power Supply (2.0-3.6V) |
| 2 | NULL | No connection / Reserved |
| 3 | OUT1 | Output 1 |
| 4 | NC | No Connection |
| 5 | OUT2/PWM1 | Output 2 / PWM Output 1 |
| 6 | STAT | Status Indicator |
| 7 | OUT3/PWM2 | Output 3 / PWM Output 2 |
| 8 | OUT4/PWM3 | Output 4 / PWM Output 3 |
| 9 | OUT5 | Output 5 |
| 10 | OUT6 | Output 6 |
| 11-13 | NC | No Connection |
| 14 | KEY6 | Key Input 6 |
| 15 | KEY5 | Key Input 5 |
| 16 | KEY4 | Key Input 4 |
| 17 | KEY3 | Key Input 3 |
| 18 | KEY2 | Key Input 2 |
| 19 | TXD | UART Transmit Data |
| 20 | RXD | UART Receive Data |
| 21 | KEY1 | Key Input 1 |
| 22 | PWRC | Power Control |
| 23 | RESET | Reset Pin |
| 24 | GND | Ground |
Basic Connection
For general transparent data transmission applications, only the following four pins are typically required to be connected:
- VCC: Connect to your power supply (2.0-3.6V).
- GND: Connect to ground.
- RXD: Connect to the TXD pin of your microcontroller or host device.
- TXD: Connect to the RXD pin of your microcontroller or host device.
Other pins (OUTx, KEYx, PWMx, STAT, RESET, PWRC) are used for advanced functionalities and specific operating modes, as detailed in the comprehensive user manual.
For detailed setup instructions and AT command configurations, please refer to the official user manual PDF: JDY-28M User Manual (PDF).
4. Operating Modes
The JDY-28M module supports several operating modes, each tailored for different applications:
4.1. BLE Master-Slave Transparent Transmission Mode
In this mode, the module can act as either a BLE master or a slave device, facilitating transparent data transmission between connected devices. Data sent to the module's UART interface is transmitted over Bluetooth, and data received via Bluetooth is output through the UART.
4.2. MESH Transmission Mode
The MESH mode enables multiple JDY-28M modules to form a network, extending the communication range and improving stability. Each module in the MESH network can act as a relay, forwarding data between other modules. This mode supports a 1K Byte transmission rate and offers completely transparent data transmission, making it a suitable replacement for 485 communication in some scenarios. The MESH relay time is within 5ms, and the minimum packet interval is 20ms for 20Byte data transmission. The module includes a network status LED light to indicate its MESH network state.
4.3. Car Key Mode
This mode is designed for car key applications, supporting the binding of up to 5 mobile phones. Users can configure automatic unlocking distances and departure locking distances via instructions. Mobile phones can be managed through specific instructions, and key binding is supported during phone pairing. After connecting to a dedicated APP, the APP sends binding instructions to the module.
4.4. Switch Panel Mode
In switch panel mode, the module supports one-click synchronous control of multiple switches or mutual control between single or multiple switches. It also provides one-click full open and full close functions, simplifying control for lighting or other switch-based systems.
5. Maintenance
To ensure the longevity and optimal performance of your JDY-28M module, please observe the following maintenance guidelines:
- Operating Environment: Operate the module within the specified working temperature range of -40℃ to 85℃. Avoid extreme temperatures or rapid temperature changes.
- Power Supply: Ensure the power supply voltage remains within the 2.0-3.6V range. Incorrect voltage can damage the module.
- Soldering: When soldering the module, adhere to the recommended SMT soldering temperature of less than 260℃ to prevent damage to internal components.
- Handling: Handle the module with care to avoid physical damage. Static electricity can harm sensitive electronic components, so use appropriate ESD precautions.
- Cleaning: Keep the module clean and free from dust, moisture, and corrosive substances. Use a soft, dry cloth for cleaning if necessary.
6. Troubleshooting
If you encounter issues with your JDY-28M module, consider the following common troubleshooting steps:
- No Power/Module Not Responding:
- Verify that the VCC and GND connections are correct and that the power supply voltage is within the 2.0-3.6V range.
- Check for any short circuits or incorrect wiring. - Unable to Connect/Pair:
- Ensure the module is powered on and within the communication range (up to 150m in open areas).
- Check if other Bluetooth devices are causing interference.
- Confirm that the module is in the correct operating mode (e.g., master or slave) for your application.
- For MESH mode, ensure all modules are properly configured and within range of each other. - Data Transmission Errors:
- Verify UART connections (TXD to RXD, RXD to TXD) and baud rate settings.
- Check for data format mismatches between the module and the host device.
- In MESH mode, ensure the network is stable and there are no excessive packet losses. - Interference Issues:
- Bluetooth communication can be affected by other 2.4GHz devices (Wi-Fi, other Bluetooth devices). Try to minimize interference sources.
- For the IPEX version, ensure the external antenna is properly connected and positioned for optimal signal. - Module LED Status:
- Observe the network status LED (if applicable) for indications of connection status or errors. Refer to the detailed PDF manual for LED behavior descriptions.
For more in-depth troubleshooting or specific error codes, consult the comprehensive JDY-28M User Manual (PDF).
7. User Tips
- Antenna Selection: If your application requires longer range or operates in an environment with potential obstructions, consider using the JDY-28M-IPEX version with an external antenna for improved signal strength and flexibility in antenna placement.
- Power Consumption: For battery-powered applications, utilize the module's sleep modes (MESH sleep current 1uA, Deep Sleep Mode 1uA) to conserve power when not actively transmitting or receiving data.
- UART Configuration: Always double-check your UART baud rate, data bits, parity, and stop bits settings to ensure they match the module's configuration for reliable communication.
- Firmware Updates: Keep an eye on the manufacturer's website for any potential firmware updates that might offer new features, performance improvements, or bug fixes.
8. Warranty and Support
This JDY-28M Bluetooth 5.2 Module is manufactured by baishundianzi. For warranty information, technical support, or further inquiries, please contact the seller or manufacturer directly. Keep your purchase records for any warranty claims.
