Function introduction: 1. Support Bluetooth audio, BLE data transmission, U disk playback, TF card playback. Support MP3/WAV/FLAC/APE format decoding 2. Optional: Serial AT command control. Support to modify the baud rate. Modify Bluetooth name, specify device playback, and mobile data passthrough 3. Support BLE and SPP dual-mode data transparent transmission, colleagues can also broadcast Bluetooth audio, no conflict 4. Support Bluetooth call, multi-button control. The last song, the next song. play / Pause. Adjust the volume and other simple functions. 5. Support to get the full file name of the play. Serial port specified path to play, loop or single play 6. Support 128KBS recording function, TF card or U disk. Recording delete playback, etc. 7. Rich usage information, reference PCB, use video tutorial, mobile phone transparent video tutorial. Serial AT video tutorial 8. Easily dock existing apps, or develop WeChat applets to implement mobile phone control Color: green Material: plastic