37-5V DIY Bluetooth 50 Audio Receiver Module MP3 Bluetooth Decoding Board With Microphone And Switch BT 50 Product selling points 1. The product is compact and easy to carry. 2. Easy to use and operate. 3. Long service life and reliable quality. 4. Excellent quality, exquisite workmanship, and excellent materials. 5. Widely applicable and can be used in multiple scenarios. Main parameters: Power supply: 3.7-5V Signal to noise ratio: 90DB Total harmonic distortion+noise: -70dB Crosstalk: -86DB Supporting configuration files: A2DP/AVCTP/AVDTP/AVRCP/HFP Transmission distance: 15M (open without partition walls) Decoding format: WAV+APE+FLAC+MP3 lossless decoding, stereo output Fill while placing: This product has a circuit for charging and discharging at the same time, which can be powered by a USB power supply, truly achieving the function of charging and discharging at the same time. Solved some pain points that cannot be used during the charging process of products. When powered by a separate USB: the red light flashes, indicating normal power supply. When powered by a separate battery: the yellow light remains on, indicating that the battery is powered normally; The yellow light flashes, indicating low battery level. When USB and battery are connected simultaneously: a flashing red light indicates that the battery is charging; A constant red light indicates that the battery is fully charged. (Note that if the USB input is suddenly disconnected during the process of charging and discharging, there will be a few seconds of interruption due to the switching of charging and discharging modes. After that, Bluetooth will automatically restart, connect and maintain the previous playback state.) Voice call function for incoming calls: After the Bluetooth connection is completed, turn on the call audio mode in the Bluetooth settings. If the phone calls, you can answer or hang up the call using the PLAY/STOP button. You can choose to use the microphone of the original earphones for call delivery (provided that the earphones have call function and are 4-segment) or use the onboard microphone for call delivery When using the computer sound card: Tin the solder pads inside the two boxes corresponding to the Sound Card on the back of the module. At this time, connect them to the computer USB interface through a USB cable, and they can be used as sound cards. The sound played by the computer is output through the audio interface of the module. (Not enabled by default) detailed list: MP3 decoding board * 1 _x000D_