raspbian - How to output all audio on the I2S interface and audiojack by default? - Raspberry Pi Stack Exchange
Can I get audio input through the GPIO - Raspberry Pi Stack Exchange
Amazon.com: Audio HAT Module for Raspberry Pi 4B/3B+/3B/2B/B+/A+/Zero/Zero W/Pi Zero WH,WM8960 Hi-Fi Sound Card HAT Stereo CODEC, Play/Record : Electronics
Raspberry Pi: GPIO - General Purpose Input Output
Raspberry Pi Starter Kit Lesson 2: Introduction of Raspberry Pi GPIO « osoyoo.com