This board allows to replace the original EXT2 connector and keep both original features: You can charge the GBASP by USB-C and connect to your headphones to hear the games!
Game Boy Advance SP USB-C & Audio Kit (Installation)
https://shop.giltesa.com/product/game-boy-advance-sp-usb-c-kit/
https://shop.giltesa.com/product/game-boy-advance-sp-usb-c-kit-centered/
Thanks to these makers for publishing the information about the pinout and their experiences, it helped me to make this board:
This project is licensed under a Creative Commons license: Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
Check the LICENSE.md for more information.