How to Use Adafruit Bluefruit EZ-Link: Examples, Pinouts, and Specs

The Adafruit Bluefruit EZ-Link (Manufacturer Part ID: 1588) is a Bluetooth Low Energy (BLE) module designed to simplify wireless communication between microcontrollers and mobile devices. It provides a seamless way to integrate Bluetooth functionality into your projects, enabling wireless data transfer, programming, and control. The module is particularly well-suited for applications requiring reliable and easy-to-use Bluetooth connectivity.

• Wireless programming of Arduino boards
• Remote control of robots, drones, or other devices
• Data logging and monitoring via mobile apps
• Wireless communication in IoT (Internet of Things) projects
• Serial communication between microcontrollers and computers

The Adafruit Bluefruit EZ-Link is designed for ease of use and compatibility with a wide range of devices. Below are its key technical details:

• Bluetooth Version: Bluetooth 2.1 + EDR (Enhanced Data Rate)
• Operating Voltage: 3.3V to 5V
• Current Consumption: ~25mA (active), ~2mA (idle)
• Communication Protocol: UART (Serial)
• Baud Rate: Auto-detects standard baud rates (9600, 115200, etc.)
• Range: Up to 10 meters (line of sight)
• Dimensions: 25mm x 19mm x 4mm
• Weight: ~2g

The module has a simple pinout for easy integration into your projects. Below is the pin configuration:

The Adafruit Bluefruit EZ-Link is designed for plug-and-play operation. Follow the steps below to use it in your project:

1. Connect the VIN pin to a 3.3V or 5V power source.
2. Connect the GND pin to the ground of your circuit.
3. Connect the TX pin of the module to the RX pin of your microcontroller.
4. Connect the RX pin of the module to the TX pin of your microcontroller.
5. (Optional) Connect the RTS and CTS pins if hardware flow control is required.

1. Power on the module. The status LED will blink, indicating it is ready to pair.
2. On your mobile device or computer, search for Bluetooth devices and select "Adafruit EZ-Link".
3. If prompted, enter the default pairing code: 1234.
4. Once paired, the status LED will turn solid, indicating a successful connection.

The Adafruit Bluefruit EZ-Link can be used to wirelessly program an Arduino UNO or communicate with it. Below is an example of how to send data from the Arduino to a paired device:

// Example: Sending data from Arduino to a paired device via Bluefruit EZ-Link
// Ensure the Bluefruit EZ-Link TX is connected to Arduino RX and vice versa.

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 baud
  delay(1000);        // Wait for the module to initialize
  Serial.println("Bluefruit EZ-Link Test"); 
  // Send a test message to the paired device
}

void loop() {
  Serial.println("Hello from Arduino!"); 
  // Send a message every second
  delay(1000);
}

• Ensure proper voltage levels (3.3V or 5V) to avoid damaging the module.
• Use short, high-quality wires to minimize noise and ensure reliable communication.
• If using hardware flow control, ensure the RTS and CTS pins are properly connected.
• Keep the module within the specified range (10 meters) for optimal performance.

1. Module does not power on:

   • Verify that the VIN pin is connected to a 3.3V or 5V power source.
   • Check all connections for loose wires or poor solder joints.

2. Unable to pair with a device:

   • Ensure the module is powered on and the status LED is blinking.
   • Check that the device's Bluetooth is enabled and within range.
   • If pairing fails, try restarting both the module and the device.

3. No data transmission:

   • Verify that the TX and RX pins are correctly connected (crossed).
   • Ensure the baud rate of the microcontroller matches the module's baud rate.
   • Check for any loose connections or damaged wires.

4. Intermittent connection issues:

   • Ensure the module is within the specified range (10 meters).
   • Minimize interference from other Bluetooth devices or wireless signals.

Q: Can I use the Bluefruit EZ-Link with a 3.3V microcontroller?
A: Yes, the module is compatible with both 3.3V and 5V logic levels.

Q: Does the module support Bluetooth 4.0 or BLE?
A: No, the Bluefruit EZ-Link uses Bluetooth 2.1 + EDR, which is not BLE-compatible.

Q: Can I use the module to program an Arduino wirelessly?
A: Yes, the Bluefruit EZ-Link supports wireless programming of Arduino boards.

Q: What is the default pairing code?
A: The default pairing code is 1234.

Q: How do I reset the module?
A: To reset the module, disconnect and reconnect the power supply.

By following this documentation, you can easily integrate the Adafruit Bluefruit EZ-Link into your projects for reliable and efficient Bluetooth communication.