Just want to check on these three errors

I had to restart NR on a machine.

Seeing these errors when it is starting:

9 Jun 19:56:11 - [info] Loading palette nodes
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named rpi_ws281x

While constructing LEDNode widget: TypeError: Cannot read property 'config' of null
    at addWidget (/home/pi/.node-red/node_modules/node-red-dashboard/index.js:72:39)
    at Object.addWidget (/home/pi/.node-red/node_modules/node-red-dashboard/index.js:136:48)
    at new LEDNode (/home/pi/.node-red/node_modules/node-red-contrib-ui-led/led.js:41:28)
    at Object.createNode (/usr/lib/node_modules/node-red/node_modules/@node-red/runtime/lib/nodes/flows/util.js:483:31)
    at Flow.start (/usr/lib/node_modules/node-red/node_modules/@node-red/runtime/lib/nodes/flows/Flow.js:189:48)
    at start (/usr/lib/node_modules/node-red/node_modules/@node-red/runtime/lib/nodes/flows/index.js:329:33)
    at tryCatchReject (/usr/lib/node_modules/node-red/node_modules/when/lib/makePromise.js:845:30)
    at runContinuation1 (/usr/lib/node_modules/node-red/node_modules/when/lib/makePromise.js:804:4)
    at Fulfilled.when (/usr/lib/node_modules/node-red/node_modules/when/lib/makePromise.js:592:4)
    at Pending.run (/usr/lib/node_modules/node-red/node_modules/when/lib/makePromise.js:483:13)

I can't find a rpi_ws281x in my pallette.

The second one:
That is a bit weird.
But it is that a null has been sent to the LED node - thinking?

Ok, another one snuck in:

pam_unix(sudo:session): session closed for user root
      pi : TTY=unknown ; PWD=/home/pi ; USER=root ; COMMAND=/sbin/iwlist wlan0 scan

I'm looking at it, but may need help.

both are related.

ws281x = LED.

Ok. Thanks.

I have the ui_LED node also installed. So anyway....

How would this be happening?

On the third one:

pi@TelePi:~/.node-red $ /sbin/iwlist wlan0 scan
wlan0     Scan completed :
          Cell 01 - Address: 24:F5:A2:B2:2A:07
                    Frequency:2.437 GHz (Channel 6)
                    Quality=54/70  Signal level=-5

It works. So why would it be failing?

Someone creates a node for node-red. this node has dependencies where they import a module, in this case rpi_ws281x. Module rpi_ws281x cannot be found, this has implications: node-red will crash when trying to use that node.

I made the bad assumption that they are related, they are not - my apologies. You are using the dashboard ui_led node which is for visuals.

Do you have a node installed to control ws281x LEDs ?

The wlan command requires sudo/root for certain features of the command which could be the issue.

AKAIK, no. :frowning:

I checked my palette and there is no node for them that I can see.


The command that does that runs every 40 seconds. I found it in the flow and it is giving valid output.

On the log, it was every few seconds.

Did you only restart node-red or did you do something else too?

I edited a rogue node, but that was nothing to do with the errors.

I was (am) messing around with CSS and I goofed.
The node went rogue and I had to stop Node-red and start it in --safe mode.

After fixing the problem I started Node-Red again and saw the error.

ws281x is from some physical LED node - maybe neopixel ?
It is actually the python library so maybe the pre-reqs for the node are not installed.
(or indeed the node needs to be removed)

Curiouser and curiouser.


Further investigation required this end.