JDY-29 Bluetooth 5.2 BLE Transparent Serial Module

Connect the module's VCC to 3.3V, GND to GND, TX to Arduino RX (pin 0), and RX to Arduino TX (pin 1). Use a logic level converter if your Arduino operates at 5V, as the JDY-29 uses 3.3V logic. Power up both devices, and the module will enter pairing mode. Use a serial monitor on the Arduino or a BLE terminal app on a smartphone to establish a connection and begin transparent data exchange. Ensure baud rates match between the module's default setting (often 9600 or 115200) and your Serial.begin() command.

The default UART baud rate is typically 9600bps, but some variants may ship at 115200bps. To reconfigure parameters like baud rate, device name, or pairing PIN, you must send specific AT commands via the serial interface. Place the module into command mode by sending "AT+\r\n" (or a similar wake-up sequence as per the datasheet) during a short window after power-on. Then, issue commands like AT+BAUD=4 for 9600 or AT+BAUD=8 for 115200. Always verify the correct command set for your specific module firmware version.

No, the JDY-29 in its standard transparent serial configuration operates as a slave device supporting a single point-to-point connection (one master to one slave). It is designed for simple serial cable replacement, not multi-link or mesh networking. For simultaneous connections, you would need a module supporting Bluetooth Central/Multi-role or a dedicated Bluetooth mesh protocol. For most IoT sensor-to-gateway or device-to-phone applications, this single, stable connection is sufficient and simplifies the communication model.

The module's operating current is in the range of tens of milliamps during active transmission or connection, dropping to low microamps in deep sleep if supported by the firmware. To minimize power, design your system to wake the module only when data needs to be sent. You can control the module's power state via an MCU GPIO pin connected to its enable or reset pin, cycling power between transmission intervals. Always consult the specific JDY-29 datasheet for exact sleep current figures and the correct pin to trigger low-power modes.