I made the schematic. It took me quite a bit of time, but I did get there in the end, and actually most of the time spent was just market research, trying to find the products I could use, especially a charging circuit. I always hated adding batteries because they needed charging and step up circuits, but now with this one I can hopefully work out everything. Also a bit more about the project, this will be a (hopefully) small and compact MP3 player using a DFplayer module, a XIAO-RP2040 MCU 3 buttons for next, previous, and play/pause, and a 128x32 I2C Oled display for displaying the current song.
