Snapcast Client for Arduino

Snapcast Audio Streaming Client for Arduino

Snapcast is a multiroom client-server audio player, where all clients are time synchronized with the server to play perfectly synced audio

Feature list

• Header only C++ implementation
• PCM, Opus decoding is supported
• Auto connect to snapcast server on network
• The functionality has been tested on an ESP32
• Memory efficient implementation, so that PSRAM is not needed
• Use any output device or DSP chain suppored by the Audio Tools
• Flexible design so that you can choose from different processor implementations and synchronizers.

The disadvantage of these goals is, that you need to fine tune the solution to have it working as you want.

Description

I have rewritten the snapclient from Jørgen Kragh Jakobsen to an Arduino Library and integrated my AudioTools project to be used to define the output devices.

Example Arduino Sketch

Here is an example Arduino sketch that uses the Wifi as communication API, the WAVs codec and outputs the audio with I2S:

#include "AudioTools.h"
#include "SnapClient.h"
#include "AudioTools/AudioCodecs/CodecOpus.h" // https://github.com/pschatzmann/arduino-libopus
//#include "api/SnapProcessorRTOS.h" // install https://github.com/pschatzmann/arduino-freertos-addons

OpusAudioDecoder codec;
WiFiClient wifi;
I2SStream out;
SnapClient client(wifi, out, codec);

void setup() {
  Serial.begin(115200);
  
  // login to wifi -> Define values in SnapConfig.h or replace them here
  WiFi.begin(CONFIG_WIFI_SSID, CONFIG_WIFI_PASSWORD);
  Serial.print("Connecting to WiFi ..");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print('.');
    delay(1000);
  }

  // print ip address
  Serial.println();
  Serial.println(WiFi.localIP());

  // setup I2S to define custom pins
  auto cfg = out.defaultConfig();
  config.pin_bck = 14;
  config.pin_ws = 15;
  config.pin_data = 22;
  // cfg.buffer_size = 512;
  // cfg.buffer_count = 40;
  out.begin(cfg);

  // Use FreeRTOS
  //client.setSnapProcessor(rtos);

  // Define CONFIG_SNAPCAST_SERVER_HOST in SnapConfig.h or here
  // client.setServerIP(IPAddress(192,168,1,33));

  // start snap client
  client.begin();
}

void loop() {
  client.doLoop();
}

Change the snapserver.conf to define codec = opus and restart the snapserver with sudo service snapserver restart. You can test now your sketch e.g. with ffmpeg -i http://stream.srg-ssr.ch/m/rsj/mp3_128 -f s16le -ar 48000 /tmp/snapfifo

For further information on codecs please check the information in the Wiki!

Documentation

For further information

• consult the class documentation or
• the examples
• the Wiki

Dependencies

• Audio Tools (mandatory)
• LibOpus (optional)
• LibFLAC.h (optinal)
• CodecVorbis (optional)

Configuration

Configuration settings can be found in SnapConfig.h