Love Tomb Style No. 223-Integrated card reader MP3, AC6925A and GL827L

This module consists of several parts:

1: Charging module: I use the IP2312 series for charging. It is a switch type with larger current and less heat. The current can be programmed, so it can adapt to batteries of various capacities, including BaimA and QoM.

2: Card reading module: I used GL827 to add a USB connection to the computer. When the computer is connected, the computer can directly add and delete song files. However, there is a point that needs to be confirmed by actual measurement, because

Both GL827 and AC6925A have their own pins to power the TF card. You need to confirm whether one of the two will backfeed the other when working. Here I use a 2R resistor for current limiting.

3: Core MP3 module

AC6925A consumes less power than 6905A

AC6925A has Bluetooth 5.0 function and can support lossless sound quality, while 6905A is still 4.2

AC6905A adds FM mode. Although 6905A also has it, the relevant projects on the platform do not seem to have added this function.

Here is a list of other features that I have not added but could be added

In recording mode, you need to hang up the microphone. The recording file should be output in TF or U disk.

In LINEIN mode, the audio stand should be a separate one rather than mixed with the headphone stand.

USB reading mode is not available because the USB interface is too large.

It is not recommended to buy the AC6925A standard program version of Yunxin. Their volume adjustment range is too small.

Hengshengchuang's is better, but for unknown reasons, some ultra-high bit rate audio playback has intermittent noise and the playback speed slows down for unknown reasons.