audio-vs1053b

#Audio Driver for the audio-vs1053b Tessel audio module (VS1053B)

##Installation

npm install audio-vs1053b

##Limitations The current version of the Tessel runtime is too slow to play audio files smoothly. That means we wrote a custom C shim that handles most of the playback and recording of data. There are several consequences of the C shim:

• Any other modules that use SPI for communication will be blocked while the Audio Module is playing a buffer.
• You can only have one Audio Module attached to Tessel at a time.
• Updates to the Audio Module driver must be released in both firmware and this npm repo.

It sucks but we're expecting major runtime speed improvements to render the C shim unnecessary within the next couple of months.

##Example

// Any copyright is dedicated to the Public Domain.
// http://creativecommons.org/publicdomain/zero/1.0/

/*********************************************
This Audio Module demo sets volume, then plays
an audio file out over Headphones/Line out
*********************************************/

var tessel = require('tessel');
var fs = require('fs');
var audio = require('../').use(tessel.port('a'));

console.log('trying to connect...');
audio.on('ready', function() {
  console.log("Ready to go!");
  audio.setVolume(20, 20, function(err) {
    if (err) return console.log('err setting volume', err);
    var song = fs.readFileSync('/app/sample.mp3');
    audio.play(song, function(err) {
      if (err) {
        console.log("error playing song: ", err);
      }
      else {
        console.log("Done playing the first song");
      }
    });
  });
});

audio.on('error', function(err) {
  console.log("Failed to connect", err);
});

##Methods

* audio.setVolume(leftChannelDb, [rightChannelDb,] callback(err)) Set the output volume. Level is a Number from 0.0 to 1.0

* audio.setInput(input, callback(err)) Set the input to either 'lineIn' or 'mic'. Defaults to 'lineIn'.

* audio.setOutput(output, callback(err)) Set the output to either 'lineOut' or 'headPhones'. Defaults to 'lineOut'.

* audio.startRecording([profile] callback(err)) Start recording sound from the input. (Receive data in the 'data' event) Callback called after recording initialized (not stopped). quality is an optional argument that can be 'voice', 'wideband-voice', 'wideband-stereo', 'hifi-voice', or 'stereo-music'. Default is 'hifi-voice'.

* audio.stopRecording(callback(err)) Stop recording sound (note that may receive one more 'data' event before this completes when the buffer is flushed.)

* audio.play([audioBuff], callback(err)) Play a buffer. If no buffer is passed in, the module will attempt to resume a buffer that was paused.

* audio.pause(callback(err)) Pause the buffer

* audio.stop(callback(err)) Stop playing and flush the buffer

* audio.createPlayStream() Returns a stream that a buffer can be piped into to play audio

* audio.createRecordStream() Returns a readable stream of mic data

* audio.availableRecordingProfiles() Returns an array of available profiles

##Events

* audio.on('ready', callback()) The audio module is ready to use

* audio.on('error', callback(err)) The audio module had an error on connection

* audio.on('volume', callback(volume)) Volume was set

* audio.on('input', callback(input)) The input mode was set

* audio.on('output', callback(output)) The output mode was set

* audio.on('startRecording', callback()) Started recording from the input

* audio.on('data', callback(audioBuff)) Received recorded data

* audio.on('stopRecording', callback()) Stopped recording on the input

* audio.on('play', callback()) A buffer is beginning to be played

* audio.on('pause', callback()) Playback was paused

* audio.on('stop', callback()) Playback was stopped

* audio.on('end', callback(err) The buffer finished playing

##Further Examples See the examples folder for code.

• audio-out-no-streams: Listen to audio without using streams.

• record-sound: Record sound from the microphone without using streams.

• stream-audio-out: Stream audio from a file to Headphones/Line out

• stream-sound-to-file: Stream audio input from line in to a file.

##License

MIT APACHE