How to Use jdy33: Examples, Pinouts, and Specs

The JDY-33 is a Bluetooth module designed for wireless communication, primarily used in Internet of Things (IoT) applications. It supports serial communication (UART) and operates on the Bluetooth 4.2 protocol, making it ideal for low-power, short-range wireless data transmission. The module is compact, cost-effective, and easy to integrate into a wide range of projects, including smart home devices, wearable electronics, and industrial automation systems.

• Wireless data transmission in IoT devices
• Remote control of appliances and systems
• Smart home automation
• Wearable technology
• Industrial monitoring and control
• Wireless sensor networks

The JDY-33 module is designed to provide reliable and efficient Bluetooth communication. Below are its key technical specifications:

The JDY-33 module has 6 pins, as described in the table below:

The JDY-33 module is straightforward to use and can be integrated into a circuit with minimal effort. Below are the steps and considerations for using the module:

1. Power Supply: Connect the VCC pin to a 3.3V or 5V power source and the GND pin to ground.
2. UART Communication:
   • Connect the TXD pin of the JDY-33 to the RXD pin of the microcontroller.
   • Connect the RXD pin of the JDY-33 to the TXD pin of the microcontroller.
3. Optional Pins:
   • The STATE pin can be used to monitor the connection status.
   • The EN (KEY) pin can be used to enter AT command mode for configuration.

The JDY-33 can be configured using AT commands via a serial terminal. To enter AT command mode:

1. Pull the EN (KEY) pin HIGH.
2. Open a serial terminal (e.g., Arduino Serial Monitor) and set the baud rate to 9600 bps.
3. Send AT commands to configure the module (e.g., change the baud rate, set the device name, etc.).

Below is an example of how to use the JDY-33 module with an Arduino UNO for basic communication:

• Connect JDY-33 VCC to Arduino 5V.
• Connect JDY-33 GND to Arduino GND.
• Connect JDY-33 TXD to Arduino RX (pin 0).
• Connect JDY-33 RXD to Arduino TX (pin 1).

// Example code to send and receive data using JDY-33 with Arduino UNO

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 bps
  delay(1000);        // Wait for the module to initialize
  Serial.println("JDY-33 Bluetooth Module Ready"); 
}

void loop() {
  // Check if data is available from the Bluetooth module
  if (Serial.available()) {
    char received = Serial.read(); // Read the incoming data
    Serial.print("Received: ");    // Print the received data
    Serial.println(received);
  }

  // Send data to the Bluetooth module
  Serial.println("Hello from Arduino!"); // Send a message
  delay(2000);                           // Wait for 2 seconds
}

• Use a level shifter if the microcontroller operates at 5V logic levels to avoid damaging the JDY-33 (which operates at 3.3V logic).
• Keep the module away from sources of interference (e.g., high-frequency circuits) to ensure stable communication.
• Use proper decoupling capacitors near the power pins to reduce noise.

1. The module is not responding to AT commands.

   • Ensure the EN (KEY) pin is pulled HIGH to enter AT command mode.
   • Verify the baud rate is set to 9600 bps in the serial terminal.
   • Check the wiring connections, especially TXD and RXD.

2. Bluetooth connection is unstable or has a short range.

   • Ensure there are no physical obstructions or interference sources near the module.
   • Verify the power supply is stable and within the specified range.

3. The module does not pair with other devices.

   • Check if the module is discoverable (use the AT+NAME? command to verify the device name).
   • Ensure the other device supports Bluetooth 4.2 or is backward compatible.

4. Data transmission is not working.

   • Verify the TXD and RXD connections between the JDY-33 and the microcontroller.
   • Ensure the baud rate of the JDY-33 matches the microcontroller's UART settings.

Q: Can the JDY-33 module be used with a 5V microcontroller?
A: Yes, the JDY-33 can operate with a 5V power supply, but its logic levels are 3.3V. Use a level shifter for the TXD and RXD pins to prevent damage.

Q: How do I reset the JDY-33 to factory settings?
A: Use the AT command AT+RESET to reset the module. Ensure the module is in AT command mode before sending the command.

Q: What is the maximum data rate supported by the JDY-33?
A: The JDY-33 supports a maximum baud rate of 115200 bps, configurable via AT commands.

Q: Can the JDY-33 be used for audio transmission?
A: No, the JDY-33 is designed for data transmission only and does not support audio profiles.