Bluetooth 4.0 Stereo Audio Receiver

Product detailed description

The compact Bluetooth 4.0 wireless receiver allows you to stream stereo audio from a phone, tablet, or computer to any audio device. The module features an integrated antenna directly on the PCB and an analogue stereo output for connection to a power amplifier. It is ideal for building your own portable speaker, reviving an older amplifier, or upgrading active speaker systems. The MUTE output allows the amplifier to be automatically muted when no audio is being transmitted, while the LED output signals the connection status.

Specifications:

• Bluetooth: version 4.0, stereo audio transmission (A2DP)
• Power supply: 5 V DC (range 4.2–5.1 V)
• Range: approx. 10 m in open space
• Antenna: integrated, directly on the PCB
• Audio output: analogue stereo (left and right channel)
• Pins: 7 pins in a 2.54 mm grid
  • 5V: power supply (positive pole)
  • GND: ground (0 V)
  • L: left channel output
  • R: right channel output
  • MUTE: output for muting the power amplifier
  • LED: output for indicator LED (connection status)
  • RESET: module reset by briefly shorting to ground
• Status indication (LED):
  • Fast flashing (~0.5 s): no device connected
  • Slow flashing (~1 s): device connected, audio transmission in progress
  • Steady light: device connected, transmission inactive (MUTE output active)
• Dimensions: 30 × 20 mm
• Weight: approx. 2 g

Wiring recommendations:

• Power supply: the module is sensitive to high-frequency interference. For power supply, it is recommended to use a linear regulator (e.g. 78L05) supplemented by blocking capacitors. If you are using a DC/DC or AC/DC converter, supplement it with an LC filter according to the diagram below. If the supply voltage exceeds 5.1 V or if you are unsure, insert a protective diode (any silicon diode) in series.
• Grounding: if interference occurs during audio transmission, check the grounding conductors or choose single-point grounding. Pay attention to the connection connector – choose a precision type or solder the module directly onto the board.
• Antenna placement: the antenna is sensitive to high-frequency interference and strong electromagnetic fields. Place the module as far as possible from the power amplifier, switching power supply, metal covers, and heatsinks.
• Enclosure: a metal cover effectively shields the Bluetooth signal and may weaken it to the extent that the devices fail to pair. Keep this in mind when choosing an enclosure.
• Indicator LED connection: the current load capacity of the output is low. For direct connection, use a red LED with a 100 Ω resistor, or amplify the output using an NPN transistor.
• Purpose of the MUTE output:
  • MUTE is a status output based on whether the module is currently playing audio. When the device is paired but nothing is being transmitted (indicator LED is constantly lit), the MUTE signal is active.
  • Usage: it is used to mute the power amplifier during silence – this eliminates pops during pairing and disconnecting the phone, as well as noise between tracks. It is connected to the MUTE / STANDBY / SHDN input of the amplifier, or switches a relay or amplifier power supply via an NPN transistor.
  • Before connection: verify the active level by measuring the voltage on the MUTE pin in both audio-playing and silent states. Depending on the result, invert the signal with a transistor if necessary.
  • If you do not use the MUTE output, leave the pin unconnected – it has no effect on the audio output function.

Package contents:

• 1× Bluetooth 4.0 Stereo Audio Receiver

Note:

• This product is not a standalone functional unit and may require professional installation.
• Product images are for illustrative purposes only and may sometimes differ from the actual appearance of the item. However, this does not change their basic properties.