How to Use HW-770B-BT5.0: Examples, Pinouts, and Specs

The HW-770B-BT5.0 is a Bluetooth audio receiver module designed for wireless audio streaming. It enables seamless audio transmission from Bluetooth-enabled devices such as smartphones, tablets, and laptops. With its compact design and versatile functionality, the HW-770B-BT5.0 is ideal for integration into DIY audio projects, home audio systems, and portable speaker designs. It supports multiple audio profiles, ensuring compatibility with a wide range of devices and applications.

• Wireless audio streaming for home audio systems
• DIY Bluetooth-enabled speakers
• Car audio systems for hands-free music playback
• Portable audio devices and amplifiers
• Integration into IoT audio projects

The HW-770B-BT5.0 module is designed to deliver reliable performance with the following key specifications:

The HW-770B-BT5.0 module features a simple pinout for easy integration:

1. Power the Module: Connect the VCC pin to a 3.7V-5V DC power source and the GND pin to ground.
2. Audio Output: Connect the L_OUT and R_OUT pins to the left and right channels of your audio amplifier or speaker system. Use the 3.5mm AUX output if available.
3. Control Pin (Optional): If you want to add a physical button for pairing or play/pause functionality, connect a momentary push button to the KEY pin and ground.
4. LED Indicator: Connect an LED to the LED pin through a current-limiting resistor (e.g., 220Ω) to monitor the module's status:
   • Blinking: Ready to pair
   • Solid: Connected to a device
5. Pairing: Turn on the module and search for "HW-770B-BT5.0" on your Bluetooth-enabled device. Pair and connect to start streaming audio.

• Power Supply: Ensure a stable power supply within the specified voltage range to avoid damage to the module.
• Audio Amplifier: Use a suitable amplifier to drive speakers, as the module itself does not amplify audio signals.
• Interference: Avoid placing the module near sources of electromagnetic interference (e.g., high-power motors or Wi-Fi routers) to maintain a stable Bluetooth connection.
• Heat Dissipation: Operate the module within the recommended temperature range to prevent overheating.

The HW-770B-BT5.0 can be used with an Arduino to control pairing or play/pause functionality via the KEY pin. Below is an example code snippet:

// Arduino code to control the HW-770B-BT5.0 module
// This code toggles the KEY pin to simulate a button press for pairing or play/pause

const int keyPin = 7; // Connect the KEY pin of the module to Arduino pin 7

void setup() {
  pinMode(keyPin, OUTPUT); // Set the KEY pin as an output
  digitalWrite(keyPin, HIGH); // Keep the KEY pin high (inactive state)
}

void loop() {
  // Simulate a button press every 10 seconds
  digitalWrite(keyPin, LOW); // Pull the KEY pin low to simulate a button press
  delay(500); // Hold the button press for 500ms
  digitalWrite(keyPin, HIGH); // Release the button
  delay(10000); // Wait for 10 seconds before the next press
}

1. Module Not Powering On

   • Cause: Insufficient or incorrect power supply.
   • Solution: Verify that the VCC pin is receiving 3.7V-5V DC and the GND pin is properly connected.

2. Bluetooth Device Cannot Find the Module

   • Cause: Module is not in pairing mode.
   • Solution: Ensure the module is powered on and the LED is blinking. If not, press the button connected to the KEY pin to enter pairing mode.

3. Audio Output is Distorted

   • Cause: Poor connection or interference.
   • Solution: Check the connections to the L_OUT and R_OUT pins. Ensure the module is not placed near sources of interference.

4. Short Bluetooth Range

   • Cause: Obstructions or interference.
   • Solution: Ensure a clear line of sight between the module and the Bluetooth device. Avoid placing the module near metal objects or other wireless devices.

• Can I use the HW-770B-BT5.0 with a battery? Yes, the module can be powered by a 3.7V lithium-ion battery or a 5V USB power source.

• Does the module support hands-free calling? No, the HW-770B-BT5.0 is designed primarily for audio streaming and does not include a microphone for hands-free calling.

• Can I connect multiple devices simultaneously? No, the module supports a single active connection at a time.

• What is the maximum audio quality supported? The module supports standard Bluetooth audio quality (SBC codec) suitable for most applications.