Acxico Bluetooth 4.1 Stereo Sound Module Instruction Manual

1. Introduction

This manual provides detailed instructions for the setup, operation, and maintenance of the Acxico Bluetooth 4.1 Stereo Sound Module. This module is designed for integration into various audio projects, enabling wireless audio transmission to speakers, headphones, or other audio systems.

Key features include Bluetooth 4.1 technology for strong versatility and a wireless transmission distance of 10 meters or more. It supports both line input stereo and USB sound card functionality when connected to a computer. The module also features intuitive LED indication for operational status.

2. Product Overview

The Acxico Bluetooth 4.1 Stereo Sound Module is a compact electronic component designed for embedding into custom audio solutions. It functions as a Bluetooth audio transmitter, converting wired audio signals into wireless Bluetooth signals.

Module Components

Figure 2.1: Top view of the Bluetooth module. This image displays the primary integrated circuit, the Bluetooth antenna, and other electronic components mounted on the blue circuit board.

Figure 2.2: Bottom view of the Bluetooth module with pinout labels. This image illustrates the connection points and their respective functions, essential for wiring the module into a circuit.

Dimensions

Figure 2.3: Module dimensions. This diagram provides precise measurements for integrating the module into custom enclosures or PCBs.

3. Setup and Wiring

Proper wiring is essential for the correct functionality of the Bluetooth module. Refer to the pinout diagram (Figure 2.2) and the following connection examples.

3.1 Power Supply Connection

The module operates on a 5V power supply. Connect the +5V pin to your 5V power source and the PGND (Power Ground) pin to the system ground.

3.2 USB Sound Card Input Connection

To use the module as a USB sound card, connect the DP and DM pins to the corresponding data lines of a USB port. The module will enumerate as a USB sound card on a connected computer, allowing audio to be transmitted wirelessly via Bluetooth.

Figure 3.1: USB sound card input connection. This diagram illustrates how to wire the module for USB audio input, including power and LED indicator connections.

3.3 Line Audio Input Connection

For standard analog audio input, connect your left audio signal to IN_L, right audio signal to IN_R, and the audio ground to AGND (Audio Ground). Ensure AGND is connected to your system ground to prevent noise.

Figure 3.2: Line audio input connection. This diagram shows the wiring for analog audio input, including power and LED indicator connections.

3.4 Serial Port Control Connection

The module includes RX and TX pins for serial communication, allowing for advanced control. This port can be used to customize device names, specify MAC address connections, search for Bluetooth devices, get connection status, and disconnect devices. Connect RX to the TX of your serial controller (e.g., USB-to-TTL converter) and TX to the RX of your serial controller.

Figure 3.3: Serial port control connection. This diagram illustrates how to connect the module for serial communication, including power and LED indicator connections.

3.5 Connect Button (CON)

The CON pin is typically used as a connect or pairing button. Momentarily connecting this pin to ground can initiate pairing mode or re-sync with a previously connected device.

4. Operating Instructions

4.1 Powering On

Once correctly wired, apply 5V power to the module. The LED indicator will illuminate or flash, indicating power and operational status.

4.2 Bluetooth Pairing

1. Ensure the module is powered on. The LED will typically flash to indicate it is in pairing mode or awaiting connection.
2. On your Bluetooth-enabled device (e.g., smartphone, speaker, headphones), search for available Bluetooth devices.
3. Select the module's Bluetooth name from the list to initiate pairing. The LED indicator on the module will change its pattern (e.g., solid light) once a successful connection is established.
4. If the module does not appear or you wish to force pairing, momentarily connect the CON pin to ground.

4.3 Audio Playback

Once paired, audio played through the connected input (either line-in or USB sound card) will be transmitted wirelessly to the paired Bluetooth device.

5. Maintenance

• Environmental Conditions: Operate the module within its specified temperature and humidity ranges. Avoid extreme conditions.
• Interference: To ensure optimal performance and prevent signal degradation, avoid placing the module near other wireless devices, strong electromagnetic fields, or large metal objects.
• Cleaning: If necessary, gently clean the module with a dry, soft cloth. Do not use liquids or abrasive cleaners.
• Physical Handling: Handle the module with care to prevent damage to its components or solder joints.

6. Troubleshooting

• No Power/LED Off: Verify that the +5V and PGND connections are secure and that the power supply is providing the correct voltage.
• Cannot Pair: Ensure the module is powered on and within range of the receiving device. Try momentarily connecting the CON pin to ground to force pairing mode. Ensure no other device is already connected to the module.
• No Audio Output: Check that the module is successfully paired. Verify the audio input connections (IN_L, IN_R, AGND for line-in, or DP/DM for USB). Ensure the volume on both the source and receiving Bluetooth device is turned up.
• Background Noise/Hum: This is a common issue with audio modules. Ensure that the AGND (Audio Ground) is properly connected to the system ground. In some cases, connecting the audio ground and power supply ground together (if they are separate) can help reduce noise. Experiment with different power supply filtering (e.g., adding a capacitor) if noise persists.
• Short Wireless Range: Ensure there are no obstructions between the module and the receiving device. Avoid placing the module near metal enclosures or other sources of interference.

7. Specifications

8. Warranty and Support

This product is designed for integration by users with appropriate technical knowledge. While no explicit warranty period is provided, Acxico is committed to customer satisfaction.

If you encounter any problems with the product, please contact us with a detailed description of the issue and, if possible, include pictures. Our support team will assist you in finding a probable best solution.

For any questions or assistance, please feel free to contact Acxico customer support.