Problem playing audio file from node red

[6akaeddy2]

Hi,
"aplay somefile.wav" with or without -D default works fine om my raspberry to play audio to paired bluetooth speaker.
The same command from within exec node gives error: "aplay: main830: audio open error: unknown error 524"
Other commands issued using exec node work fine.

I controll the moving parts of my christmas village this way but no music ...

What is going wrong?

Thanks in advance

6akaeddy2

[cymplecy]

This got me audio out of the headphone socket - something similar might work for Bluetooth

[SOLVED]Not hearing sound using aplay via exec when running as service

Following on from how to get Node-RED to run as a service on a Pi I'm having trouble playing a sound via exec node So I'm trying to play a wav file out thru the Pi audio jack It works fine when I run Node-RED directly from a terminal As I was typing this I suddenly thought that the sound is probably defaulting to going out thru HDMI and with a bit of googling and experimenting I came up with this as my solution [image] which tells it to explicitly use the audio jack and all good …

[6akaeddy2]

Thanks Cymplecy,
I looked at your suggestion. Aplay should play via bluetooth. It does when invoked in a terminal session so I think this is the default now. Using "aplay -D default file.wav" using node red exec however gives the error. Tried other options then "default". "-D pulse" works from terminal. From nore red exec it gives an other error:

ALSA lib pulse.c:242:(pulse_connect) PulseAudio: Unable to connect: Connection refused

aplay: main:830: audio open error: Connection refused

using "paplay file.wav" from exec node results in "Connection failure: Connection refused
pa_context_connect() failed: Connection refused"

I'm out of idees

[Colin]

How are you running node-red? If running it as a service try stopping it (node-red-stop) and run it directly in the terminal using
node-red
If it plays now then possibly the node-red user is not in the audio group.

[6akaeddy2]

Hi Colin,
I start node red as a service, but i have to login opening the web interface. Node red exec node "whoami" returns my username, so i think (p)aplay is called as me?

Yede

[Colin]

Have you tried what I suggested?

[6akaeddy2]

Hi Colin,
I thought i did without result, now for second time is does work.
I see no user node-red in /etc/passwd? how to add it to group audio then?
added myself to pulse and pulse-access. don't know is that was smart...
What is my next step?
Thanks so far!

[Colin]

Look in the systemd service to see what is the user running the service
cat /lib/systemd/system/nodered.service
There should be lines near the start setting the User and Group.

[6akaeddy2]

[service]
Type=simple
#Run as normal pi user - change to the username you wish to ron NodepRED as
User=yede
Group=yede
WorkingDirectory=/home/yede

yede is my username. instead of standard user pi

[Colin]

So is that the same user that you were logged in as when you ran node-red. If so then it is not the group, it must be something to do with the environment when logged in via ssh versus the service running.

[6akaeddy2]

yes, same user as logged in via ssh (headless pi zero 1) and started node-red manualy

[zenofmud]

What OS are you running? You can find this by running lsb_release -c

[6akaeddy2]

hello zenofmud,

Bullseye

Tomorrow, tuesday 12-12 no time for reactions. have to go to office ;-(

[PdeJ]

When using a headless rpi running Bullseye to get aplay to work through an Exec node for Bluetooth speakers I had to make PulseAudio specifically available to Node Red. Have a look at the section of my notes PdeJ - Connect to Bluetooth

[6akaeddy2]

Thanks. Seems to the point. Will try this tomorrow evening.

[6akaeddy2]

A combination of the suggestions of PdJ and Colin seems to work. after rebooting the pizero i now issue "node-red-stop" and "node-red &". then "bluetoothctl power on" and "bluetoothctl connect mac-addres-speaker".
Then the exec node "aplay -D pulse somevfile.wav" works.

Okay for now. Would like a solution whitout manualy restarting node-red in the future. probably start node red not as a service but from login script of user?

[Colin]

You should be able to add those commands into the systemd startup script for node red.
sudo systemctl status nodered will tell you where that is.

[6akaeddy2]

Hello Colin,

With my lack of experience I need a bit more guidance.
could you give me another nudge please?

sudo systemctl status nodered just after boot is:

yede@pizero1:~ $ sudo systemctl status nodered
Failed to get journal cutoff time: Bad message
● nodered.service - Node-RED graphical event wiring tool
     Loaded: loaded (/lib/systemd/system/nodered.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2023-12-15 10:12:17 CET; 1min 31s ago
       Docs: http://nodered.org/docs/hardware/raspberrypi.html
   Main PID: 247 (node)
      Tasks: 11 (limit: 414)
        CPU: 33.011s
     CGroup: /system.slice/nodered.service
             └─247 node --max_old_space_size=256 /usr/lib/node_modules/node-red/bin/../red.js

Dec 15 10:12:17 pizero1 systemd[1]: Started Node-RED graphical event wiring tool.
Dec 15 10:12:52 pizero1 Node-RED[247]: 15 Dec 10:12:52 - [info]
Dec 15 10:12:52 pizero1 Node-RED[247]: Welcome to Node-RED
Dec 15 10:12:52 pizero1 Node-RED[247]: ===================
Dec 15 10:12:53 pizero1 Node-RED[247]: 15 Dec 10:12:52 - [info] Node-RED version: v3.1.0
Dec 15 10:12:53 pizero1 Node-RED[247]: 15 Dec 10:12:52 - [info] Node.js  version: v18.17.1
Dec 15 10:12:53 pizero1 Node-RED[247]: 15 Dec 10:12:52 - [info] Linux 6.1.21+ arm LE
Dec 15 10:13:29 pizero1 Node-RED[247]: 15 Dec 10:13:29 - [info] Loading palette nodes
Dec 15 10:13:50 pizero1 Node-RED[247]: 15 Dec 10:13:50 - [info] Dashboard version 3.6.2 started at /ui

yede@pizero1:~ $ node-red-stop

after stopping and starting like you told me it is:

● nodered.service - Node-RED graphical event wiring tool
     Loaded: loaded (/lib/systemd/system/nodered.service; enabled; vendor preset: enabled)
     Active: inactive (dead) since Fri 2023-12-15 10:33:24 CET; 3h 41min ago
       Docs: http://nodered.org/docs/hardware/raspberrypi.html
    Process: 247 ExecStart=/usr/bin/env node-red-pi $NODE_OPTIONS $NODE_RED_OPTIONS (code=exited, status=0/SUCCESS)
   Main PID: 247 (code=exited, status=0/SUCCESS)
        CPU: 51.453s

Dec 15 10:13:57 pizero1 Node-RED[247]: 15 Dec 10:13:57 - [info] Starting flows
Dec 15 10:13:59 pizero1 Node-RED[247]: 15 Dec 10:13:59 - [info] Started flows
Dec 15 10:13:59 pizero1 Node-RED[247]: 15 Dec 10:13:59 - [info] [mqtt-broker:9ef57e0297253107] Connected to broker: mqtt://localhost:1883
Dec 15 10:33:24 pizero1 systemd[1]: Stopping Node-RED graphical event wiring tool...
Dec 15 10:33:24 pizero1 Node-RED[247]: 15 Dec 10:33:24 - [info] Stopping flows
Dec 15 10:33:24 pizero1 Node-RED[247]: 15 Dec 10:33:24 - [info] [mqtt-broker:9ef57e0297253107] Disconnected from broker: mqtt://localhost:1883
Dec 15 10:33:24 pizero1 Node-RED[247]: 15 Dec 10:33:24 - [info] Stopped flows
Dec 15 10:33:24 pizero1 systemd[1]: nodered.service: Succeeded.
Dec 15 10:33:24 pizero1 systemd[1]: Stopped Node-RED graphical event wiring tool.
Dec 15 10:33:24 pizero1 systemd[1]: nodered.service: Consumed 51.453s CPU time.

---

/lib/systemd/system/nodered.service is:

# systemd service file to start Node-RED

[Unit]
Description=Node-RED graphical event wiring tool
Wants=network.target
Documentation=http://nodered.org/docs/hardware/raspberrypi.html

[Service]
Type=simple
# Run as normal pi user - change to the user name you wish to run Node-RED as
User=yede
Group=yede
WorkingDirectory=/home/yede

Environment="NODE_OPTIONS=--max_old_space_size=256"
# define an optional environment file in Node-RED's user directory to set custom variables externally
EnvironmentFile=-/home/yede/.node-red/EnvironmentFile
# uncomment and edit next line if you need an http proxy
#Environment="HTTP_PROXY=my.httpproxy.server.address"
# uncomment the next line for a more verbose log output
#Environment="NODE_RED_OPTIONS=-v"
# uncomment next line if you need to wait for time sync before starting
#ExecStartPre=/bin/bash -c '/bin/journalctl -b -u systemd-timesyncd | /bin/grep -q "systemd-timesyncd.* Synchronized to time server"'

ExecStart=/usr/bin/env node-red-pi $NODE_OPTIONS $NODE_RED_OPTIONS
#ExecStart=/usr/bin/env node $NODE_OPTIONS red.js $NODE_RED_OPTIONS
# Use SIGINT to stop
KillSignal=SIGINT
# Auto restart on crash
Restart=on-failure
RestartSec=20
# Tag things in the log
SyslogIdentifier=Node-RED
#StandardOutput=syslog

[Install]
WantedBy=multi-user.target
------

[Colin]

Actually there may be an easier way. What happens if you run an exec node containing
bluetoothctl power on ; bluetoothctl connect mac-addres-speaker
before your aplay exec node?

[6akaeddy2]

Hi Colin,

Sorry for late reaction. Busy period of the year.
I issue both commands. Manuallly when testing, or as part of the script that runs my music, steppermotors and servo's.
For now I can live with the current situation: restart node-red manually after booting the pizero and don't switch it off until next year.
happy hollidays.
Yede