DollaTek Bluetooth Decoder Board (Model ELA18784) User Manual

1. Introduction

This manual provides comprehensive instructions for the DollaTek Bluetooth Decoder Board, Model ELA18784. This module is designed as a Bluetooth audio receiver, outputting standard analog audio signals. It also features an AUX input for connecting other audio sources, making it suitable for DIY audio projects, including modifying speakers or integrating into custom audio systems.

Key features include Bluetooth 4.2 connectivity, a wide working voltage range, power reverse protection, and dual input/output terminals for versatile integration.

2. Product Overview

The DollaTek Bluetooth Decoder Board is a compact circuit board with various connection points and indicators. Understanding these components is crucial for proper setup and operation.

Figure 2.1: The DollaTek Bluetooth Decoder Board, showing the 3.5mm audio output terminals. These jacks are used for connecting to external audio devices or amplifiers.

Figure 2.2: A detailed view of the board with key components labeled. This includes the dedicated audio relay, blue working indicator, low noise LDO chip, gold-plated copper 5V power supply port, 3.5mm audio output terminal, 2.54mm 3P audio output terminal, 3.5mm AUX input terminal, 2.54mm 3P AUX input terminal, external antenna interface, and onboard antenna. The DC5-12V additional wiring terminal is also visible.

Figure 2.3: This image illustrates the power input options. The Universal Micro USB 5V power supply terminal is on the right. Below it, the additional DC5-12V wiring power supply terminal is shown, with indications for connecting DC negative (black wire) and DC positive (red wire). The spring leaf mechanism for conductor changes is also noted.

Figure 2.4: This image provides information on the Bluetooth name, connection status indicators, and supported audio decoding formats. The Bluetooth name is LQSCBT, and it supports automatic reconnection. Status indicators include fast flashing (waiting for connection), slow flashing (audio is playing), and steady on (connected). Supported decoding formats are AAC, FLAC, APE, WMA, and WAV.

3. Specifications

4. Setup

Follow these steps to set up your DollaTek Bluetooth Decoder Board:

1. Power Connection:
   • The module requires a DC 5V-12V power supply.
   • You can power the board via the Micro USB 5V port or the DC5-12V additional wiring terminal.
   • When using the wiring terminal, ensure correct polarity: connect the positive wire to the '+' terminal and the negative wire to the '-' terminal. The board includes power reverse protection.
2. Audio Output Connection:
   • Connect your amplifier or speaker system to one of the audio output terminals.
   • Options include the 3.5mm audio jack (OUT) or the 2.54mm 3P audio output terminal.
3. AUX Input Connection (Optional):
   • If you wish to connect an external audio source (e.g., an MP3 player without Bluetooth), use one of the AUX input terminals.
   • Options include the 3.5mm AUX jack or the 2.54mm 3P AUX input terminal.
4. External Antenna (Optional):
   • For improved Bluetooth range, especially when installing the module in a metal enclosure, connect an external antenna to the designated external antenna interface.

5. Operating Instructions

Once the module is powered and connected, follow these steps for operation:

1. Power On: Apply power to the module. The blue LED indicator will begin to flash.
2. Bluetooth Pairing:
   • On your Bluetooth-enabled device (e.g., smartphone), search for available Bluetooth devices.
   • Select the device named LQSC_BT to pair.
   • Once connected, the blue LED indicator will turn steady on. The module supports automatic reconnection to previously paired devices.
3. Audio Playback:
   • After successful pairing, play audio from your connected Bluetooth device.
   • The blue LED indicator will flash slowly when audio is playing.
   • The module supports decoding formats such as AAC, FLAC, APE, WMA, and WAV.
4. AUX Input Functionality:
   • When Bluetooth is not connected, the audio signal from the AUX input terminal is directly passed through to the OUT terminal.
   • When Bluetooth is connected, the Bluetooth audio signal is output from the OUT terminal, and the AUX input is automatically disconnected. This ensures priority for the Bluetooth audio source.

6. LED Indicator Description

• Fast flashing: The module is waiting for a Bluetooth connection (pairing mode).
• Slow flashing: Audio is currently playing via Bluetooth.
• Steady on: The module is successfully connected to a Bluetooth device, but no audio is currently playing.

7. Maintenance

To ensure the longevity and optimal performance of your DollaTek Bluetooth Decoder Board, consider the following:

• Operating Environment: Operate the module within its specified working temperature range of -40℃ to 85℃. Avoid extreme temperatures, high humidity, or dusty environments.
• Cleaning: If necessary, gently clean the board with a dry, soft cloth. Do not use liquids or harsh chemicals.
• Handling: Handle the board with care to avoid damaging components or connections. Avoid static discharge.

8. Troubleshooting

If you encounter issues with your DollaTek Bluetooth Decoder Board, refer to the following troubleshooting guide:

• No Power / Module Not Turning On:
  • Verify that the power supply is connected correctly to either the Micro USB port or the DC5-12V terminal.
  • Ensure the input voltage is within the DC 5V-12V range.
  • Check for any loose connections or damaged wires.
• No Audio Output:
  • Confirm that your amplifier or speaker system is properly connected to the audio OUT terminals.
  • Check the volume level on your connected Bluetooth device and your amplifier/speakers.
  • If using Bluetooth, ensure the module is successfully paired (LED steady on or slow flashing).
  • If using AUX input, ensure Bluetooth is not connected, as the AUX input is disconnected when Bluetooth is active.
  • Some setups may require an external amplifier for variable volume control, as noted by users.
• Bluetooth Not Connecting / Pairing Issues:
  • Ensure the module's blue LED is fast flashing, indicating it is in pairing mode.
  • On your device, turn Bluetooth off and then on again, then rescan for devices.
  • Make sure your device is within range of the module.
  • If the module was previously paired with another device, ensure that device's Bluetooth is off or out of range, or manually disconnect it.
• Poor Audio Quality / Static:
  • Ensure all audio connections are secure and free from interference.
  • Check the quality of the audio source.
  • If experiencing range issues, consider using an external antenna.

9. Safety Information

Please observe the following safety guidelines:

• Do not expose the module to water or excessive moisture.
• Ensure proper ventilation if enclosing the module.
• Only use power supplies within the specified voltage range (DC 5V-12V).
• This product is intended for DIY electronics enthusiasts. Exercise caution when handling electronic components and making electrical connections.