Saturday, May 29, 2021

Bluetooth Stereo Audio Receiver JDY-62 module and the Bluetooth 4.0 CSR dongle transmitter

JDY-62 is an affordable Bluetooth stereo audio receiver module with great sound qualities for the price provided the ground connection is properly made. To send audio from PC to the JDY-62 module I have used the Bluetooth 4.0 CSR dongle transmitter that works well on Windows 10 and acts like a sound card.

Bluetooth Stereo Audio Receiver JDY-62 module and the Bluetooth 4.0 CSR dongle transmitter

JDY-62 module pinout

JDY-62 module pinout

1 - VCC - 5V. From what I have read the module can also be powered from 3.7V by shorting the diode above the pin.

2 - GND - power ground and unfortunately the audio ground. Unfortunately because the high current pulses creates a voltage drop raising the ground potential and if the impedance to ground is too high it will produce modem-like sounds. For this reason the audio ground (G2 in the following schematic) must be connected as close as possible to the pin 2 (G1 in the schematic).

3 - L - left channel audio output that goes to the tip of the headphones jack.

4 - R - right channel audio output that goes to the ring of the headphones jack.

5 - MUTE - mutes the module. There is not much documentation about this but I think it must be HIGH to mute the sound and LOW for normal mode.

6 - KEY - 3 push buttons can be connected to this pin. One directly to ground for Play/Pause, a second one through a 22k resistor for next track or volume up on long press and a third one connected to ground through 15k resistor for previous track or volume down on long press.
 

How to connect the JDY-62 Bluetooth module

JDY-62 Bluetooth module wiring connections schematic

C1 is a 100n ceramic capacitor for fast transients currents and C2 is for slow currents. C3 and C4 removes the DC bias and higher values gives bigger base.

In order to avoid modem-like beeping sounds, power ground G1 and audio ground G2 must be connected together as close as possible to the pin 2 (GND) of the JDY-62 module.

The Bluetooth antenna must be kept away from any metal that could block the radio signal and the power lines should not pass beneath the antenna because that could also induce beeping sounds on the output.

Connecting JDY-62 module to an audio amplifier

The above schematic worked well for headphones but when I tried using an audio amplifier the beeping noises appeared no matter how I connected the grounds. After tinkering for a while I found out that disconnecting the audio ground (G2) solved the problem and the audio was crystal clear.


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