Audio Playback

TinyCLR can play uncompressed WAV audio directly through the built-in DAC, and play MP3 by offloading decoding to an external decoder chip. Codec drivers for both live in the TinyCLR-Drivers repository.

WAV

WAV playback is a thin pipeline: read PCM samples from the file (or from a baked-in resource) and push them to the DAC at the sample rate the file specifies. The WAV driver in TinyCLR-Drivers handles the header parsing and the sample-timing loop — you supply the source bytes and a DAC channel.

The example below plays a WAV file from an SD card on the SC20100S Dev Board:

using GHIElectronics.TinyCLR.Devices.Dac;
using GHIElectronics.TinyCLR.Devices.Storage;
using GHIElectronics.TinyCLR.Drivers.Audio;     // From TinyCLR-Drivers — see repo for source.
using GHIElectronics.TinyCLR.IO;
using GHIElectronics.TinyCLR.Pins;
using System.IO;

// Mount the SD card.
var sd = StorageController.FromName(SC20100.StorageController.SdCard);
var drive = FileSystem.Mount(sd.Hdc);

// Open the DAC channel that drives the audio output.
var dac = DacController.GetDefault().OpenChannel(SC20100.Dac.Channel.PA4);

// Pass the file stream and the DAC channel to the WAV player.
using var wavStream = new FileStream(drive.Name + "music.wav", FileMode.Open);

var player = new WavPlayer(dac);
player.Play(wavStream);             // Blocks until playback finishes.

For maximum efficiency on small devices, parse the WAV on a PC and embed just the PCM sample bytes (plus the sample rate) as a resource. At runtime, push the samples directly to the DAC at the correct rate — no header parsing, smaller resource footprint than the original .wav.

The exact WavPlayer API and the PCM-direct pattern live in the TinyCLR-Drivers repository — that's the canonical reference for the driver.

The DAC output is a clean line-level signal — for a speaker, you'll need an external audio amplifier. See Analog Out → Other ways to output analog signals for the signal-conditioning side.

MP3

MP3 decoding on the SITCore CPU itself isn't practical — MP3 decode is computationally heavy and requires a license. Instead, TinyCLR works with external MP3 decoder chips, most commonly the VLSI Solution VS1053 family.

The flow:

1. The SITCore reads MP3 bytes from a file or network stream.
2. Streams them over SPI to the VS1053.
3. The VS1053 decodes in hardware and drives a speaker through its own audio output.

The driver for the VS1053 lives in the TinyCLR-Drivers repository — the same place as the WAV driver. Other VLSI parts (VS1003, VS1063) follow similar patterns.

API reference

Namespace	Description
GHIElectronics.TinyCLR.Devices.Dac	DAC controller and channel classes