Module highlights: 

Super sound quality, on-board 2W mono power amplifier (5V power supply up to 3W) directly connected to the horn (4 Ω  The 3.5mm gold-plated earphone socket can be connected with earphone or external audio.
With microusb power supply interface, mobile power supply or USB charger can be used for power supply through mobile data cable, or 3.7V lithium battery and USB 5V power supply can be used.
Support TF Card (mobile phone memory card), U disk play mode.
With horn terminal, no need to weld, convenient wiring.
The module design is convenient for modification.

Product overview:

1) Support mp3 format, power on automatically play, play state red LED indicator update.
2) Support u disk (tested 32g), TF Card (tested 16g) play mode; Power on the default TF card mode, if the TF card does not exist, automatically jump to the U disk mode, and both devices are installed, you can manually set the playback mode, please see the key operation instructions for details.
3) Press the key to adjust the up and down track switching, volume + -, pause / play, mode switching. Please refer to the key operation instructions for details.
4) You can press the key to set the "single / full" cycle. The full cycle is the default when power on. Press the "repeat" key to change the cycle mode

Key operation instructions

"Prev / V --" key: "short press" to switch to "previous" song, "long press" to "volume down"
"Next / V + +" key: "short press" to switch to "next" song, "long press" to "volume up"
"P / P / mode" key: "short press" for "play / pause" switch, "long press" for U disk, TF Card "mode" selection
"Repeat" key: "short press", for "single / full" cycle switching (no long press function)
Note: 1. "Long press" takes about 2S
2. If U disk mode is used, 5V power supply is recommended. Some U disks do not support 3.7V power supply.

Product parameters:

Product Name: MP3 lossless decoder board (supporting TF Card / U disk)
Power supply range: 3.7 ~ 5.5V
Product size: 45.72mm * 35.14mm * 12.0mm (L x W x H)
Color: blue product weight: 11.3g (including packaging)
Packaging: single module electrostatic bag packaging material: FR4 + electronic element
schematic diagram: http://www.chipkingdom.com/upfile/201531917474080714.pdf