rpi4-osdev/part9-sound/README.md

Writing a "bare metal" operating system for Raspberry Pi 4 (Part 9)

Playing sound from the audio jack

One thing our game is missing is the excitement of sound! Some beeps and squeaks would be a wonderful addition to make the gameplay more compelling. Let's work to do just that!

This code was derived from Peter Lemon's work, for which I am very grateful. It's been ported to C with some modifications to work on the Raspberry Pi 4 hardware.

Todo

• Write-up the CPU-driven playaudio_cpu() code, explaining clocks/PWM etc.
• Write-up the DMA version playaudio_dma() version, which doesn't tie up the CPU but still plays sound!
• Add a Makefile.gcc (I'm using LLVM Clang these days, so not a priority)