MH-M18 Wireless Bluetooth Audio Receiver Board

MH-M18 Wireless Bluetooth Audio Receiver Board is a high-fidelity, low-power consumption Bluetooth solution designed to transform standard speakers into wireless audio systems. This compact module supports the latest Bluetooth 4.2 protocol, ensuring stable transmission and high-quality sound reproduction with minimal latency. Furthermore, its simple interface allows hobbyists and engineers to integrate wireless connectivity into DIY projects without complex programming. Users can power the board easily via a 5V micro-USB connection or a lithium battery, providing immense flexibility for portable applications. Consequently, this board represents a cost-effective choice for modernizing legacy audio equipment. Therefore, you should consider the MH-M18 for any project requiring a reliable, plug-and-play Bluetooth audio interface.

Key Features:

• Bluetooth 4.2 Technology: Provides a stable wireless connection with a range of up to 20 meters in open spaces.
• Lossless Audio Support: Decodes various formats including WAV, WMA, FLAC, APE, and MP3 for high-quality listening.
• Dual Power Input: Offers the convenience of a micro-USB port for 5V input or dedicated solder pads for a 3.7V lithium battery.
• Plug-and-Play Operation: Requires no driver installation; however, it automatically enters pairing mode upon power-up for immediate use.
• Compact Form Factor: Features a tiny footprint, making it suitable for integration into small enclosures or headphone housings.

Technical Specifications:

• Bluetooth Version: V4.2
• Operating Voltage: 3.7 V to 5 V DC
• Maximum Operating Current: 20 mA
• Transmission Distance: ≈ 20 m (Maximum)
• Sensitivity: −87 dBm
• Signal-to-Noise Ratio (SNR): 90 dB
• Total Harmonic Distortion (THD): ≤ −70 dB

Mechanical Specifications:

• PCB Material: High-quality FR-4 fiberglass
• Mounting: Surface mount or through-hole soldering via 2.54 mm pitch pads
• Audio Output: Stereo (Left and Right channels)
• Interface: Micro-USB and solder pads

Dimensions:

• Board Length: 23 mm
• Board Width: 11 mm
• Board Height: ≈ 2.5 mm
• Pad Pitch: 2.54 mm (Standard header compatibility)

Pinout and Wiring:

• 5V / VBAT: Connect to a 5 V DC power source or a 3.7 V lithium battery.
• GND: Connect to the power supply ground.
• L (Left Channel): Connect to the left input of an audio power amplifier.
• R (Right Channel): Connect to the right input of an audio power amplifier.
• AGND (Audio Ground): Common ground for the audio signals to prevent noise interference.
• Wiring Note: Avoid placing the Bluetooth antenna section near metal objects; otherwise, signal range may decrease significantly.

Datasheet Reference:

• Download MH-M18 Bluetooth Audio Receiver Datasheet

Commonly Used in:

• Active Speakers: Converting standard wired bookshelf speakers into wireless Bluetooth monitors.
• Car Audio Systems: Adding wireless streaming capabilities to older vehicles via the AUX input.
• Portable Boomboxes: Providing the audio backbone for custom-built battery-powered sound systems.

Applications:

• DIY Wireless Headphones: Modifying high-quality wired headphones for Bluetooth operation.
• Smart Home Audio: Distributing audio wirelessly to various rooms in a home automation setup.
• Voice Prompts: Integrating wireless voice feedback into robotics or industrial control systems.

Equivalent Models:

• MH-M28: A similar model featuring an integrated 3.5 mm headphone jack for direct output.
• MH-M38: An upgraded version that includes a built-in 5W+5W dual-channel power amplifier.
• Bluetooth BK8000L: A common alternative module; however, it typically requires more complex AT command configuration.

Package Includes:

• 1 x MH-M18 Wireless Bluetooth Audio Receiver Board