node-red-contrib-speakerpi 0.0.38

Node Red Nodes for Speaker Output on Raspberry PI

npm install node-red-contrib-speakerpi

A Node-RED node to give a provided sound (WAV,OGG) out on the defined output (hdmi or chinch or defined). This node is designed to work on Raspberry Pi and will be good in using with Watson APIs like text-to-speach to demonstrate cognitive iot.


Run the following command in the root directory of your Node-RED install or home directory (usually ~/.node-red).

    npm install node-red-contrib-speakerpi

Additionally you have to install on the Raspberry Pi

sudo apt-get install libasound2-dev

sound set to Analog output

amixer cset numid=3 1

sound set to HDMI

amixer cset numid=3 2

sound set volume


Additional Info

This node runs fine with the NodeJS 6.x LTS and NPM v3.


Provides a sound-node for sending out a sound to the connected speaker. There are two modes - filebased and streambased.


Within the filebased mode the buffer is dumped to an file and the Raspberry Pi Player APLAY is called in background with this file. This brings out best quality with minimum resources needed from the play. The msg.speech should contain the WAV/OGG file (mybe directly from Text2Speach Service from Bluemix). This will be dumped into a file and after playing the temporary file it will be deleted.


You can also play own pregiven files by using msg.filename (like /path/filename.wav). The msg.choose has then set to "givenfile" and msg.filename to the name with path.


The streambased mode is for streaming directly the buffer into a speaker framework (using node-speaker) which is from the quality perspective not very good.

speakerPi output node

If msg.speech as an input contains the WAV/OGG .

The node also needs a defined sound configuration which contains channels (1 or 2), the bitdepth (8 or 16) and the samplerate (11025, 22050 or 44100) set in the node or in the msg.speakerConfig for the sound in msg.speech.

speakerConfig = { 
    channels: 1
    bitdepth: 16
    samplerate: 22050

Node Info

Version: 0.0.38
Updated 1 year, 2 months ago
License: Apache-2.0


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  • speakerpi-output


  • node-red
  • raspi
  • speaker


  • ohahn