Invalid input: NaN using rpi gpio

[bjo]

Hi,
I'm trying to get the following flow working. According to the debug output of "on" or "off", msg.payload is "1" or "0" as a number. But the status of pump says Invalid input: NaN and nrgpio python command not running, but

sudo -u nodejs-node-red ./nrgpio 11 1

works fine.

Flow in json:

[{"id":"9c89b46.7714ec8","type":"mqtt in","z":"8ce28174.9fb388","name":"","topic":"moisture","qos":"2","datatype":"auto","broker":"4eca0d68.048e1c","x":110,"y":140,"wires":[["6e2d378b.4cead"]]},{"id":"9f0cdea8.902a58","type":"switch","z":"8ce28174.9fb388","name":"moisture-check","property":"payload","propertyType":"msg","rules":[{"t":"lte","v":"150","vt":"num"},{"t":"gt","v":"150","vt":"num"}],"checkall":"false","repair":false,"outputs":2,"x":280,"y":140,"wires":[["6e928127.00bcb"],["cbd6ccf6.bdd2f"]]},{"id":"6e928127.00bcb","type":"change","z":"8ce28174.9fb388","name":"on","rules":[{"t":"set","p":"payload","pt":"msg","to":"1","tot":"num"}],"action":"","property":"","from":"","to":"","reg":false,"x":540,"y":100,"wires":[["9dfe863e.05ef28","4cbb16b7.84f4"]]},{"id":"cbd6ccf6.bdd2f","type":"change","z":"8ce28174.9fb388","name":"off","rules":[{"t":"set","p":"payload","pt":"msg","to":"0","tot":"num"}],"action":"","property":"","from":"","to":"","reg":false,"x":500,"y":180,"wires":[["9dfe863e.05ef28","4cbb16b7.84f4"]]},{"id":"904486c0.910a88","type":"inject","z":"8ce28174.9fb388","name":"","topic":"","payload":"100","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":130,"y":220,"wires":[["9f0cdea8.902a58"]]},{"id":"bc7c5992.5168","type":"status","z":"8ce28174.9fb388","name":"","scope":null,"x":520,"y":300,"wires":[["4cbb16b7.84f4"]]},{"id":"6e2d378b.4cead","type":"debug","z":"8ce28174.9fb388","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":280,"y":80,"wires":[]},{"id":"9dfe863e.05ef28","type":"debug","z":"8ce28174.9fb388","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":740,"y":60,"wires":[]},{"id":"4cbb16b7.84f4","type":"rpi-gpio out","z":"8ce28174.9fb388","name":"pump","pin":"11","set":"","level":"0","freq":"","out":"out","x":740,"y":180,"wires":[]},{"id":"4eca0d68.048e1c","type":"mqtt-broker","z":"","name":"localhost","broker":"localhost","port":"1883","clientid":"","usetls":false,"compatmode":false,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""}]

[zenofmud]

@bjo welcome to the forum!

Why are you sending the output of the status node to the gpio node? that is what is causing the issue.
send it to a debug node.

[Steve-Mcl]

Hi, pretty sure you shouldn't be running node-red as sudo but hey ho.

Put debug nodes on all outputs of all nodes & see what is actually going into the pump. Trace it back to see where the problem originates.

If you get stuck, put a unique name all your debug nodes, screen shot the flow and debug output. (The named debug nodes help someone correlate each message in the debug window to the screenshot)

[bjo]

I just tried to get an idea why nrgpio python command not running happens, I thougt the status node could tell me that. But the python command is also not running when pump gets triggered correctly.

[zenofmud]

@bjo

I thougt the status node could tell me that.

It can tell you some information, but you don't want to send it to the gpio node since that expect to see a 1 or 0 ot true or false. Send it to a debug node

Or are you saying you want to see the status displayed in the backend but not in the debug node?

@bjo

nrgpio python command not running

where are you seeing that?

[bjo]

According to the debug node, the sent numbers to the gpio node are correct. But the debug window still tells nrgpio python command not running and I have no clue why the python command fails.

[Colin]

How did you install node-red? Did you use the recommended script from
https://nodered.org/docs/getting-started/raspberrypi

[zenofmud]

Try running sudo apt install rpi.gpio and restart NR and see what happens

[bjo]

It's already installed, testgpio.py from node-red-node-pi-gpio throws no exception.
But running ./nrgpio out 11 1 as node-red-user throws

Traceback (most recent call last):
  File "./nrgpio.py", line 84, in <module>
    GPIO.setup(pin,GPIO.OUT)
RuntimeError: No access to /dev/mem.  Try running as root!

So I should check the udev rules.

[bjo]

It's installed from AUR: https://aur.archlinux.org/packages/nodejs-node-red/ as also python-raspberry-gpio, node-red-node-pi-gpio was installed manually.

[Colin]

Google suggests that error can be caused by mis-matched versions of s/w. Are you running Arch Linux rather than Raspbian?

[bjo]

Thanks for all your help! Finally I stumpled upon https://sourceforge.net/p/raspberry-gpio-python/tickets/115/, put

SUBSYSTEM=="bcm2835-gpiomem", KERNEL=="gpiomem", GROUP="gpio", MODE="0660"
SUBSYSTEM=="gpio", KERNEL=="gpiochip*", ACTION=="add", PROGRAM="/bin/sh -c 'chown root:gpio /sys/class/gpio/export /sys/class/gpio/unexport ; chmod 220 /sys/class/gpio/export /sys/class/gpio/unexport'"
SUBSYSTEM=="gpio", KERNEL=="gpio*", ACTION=="add", PROGRAM="/bin/sh -c 'chown root:gpio /sys%p/active_low /sys%p/direction /sys%p/edge /sys%p/value ; chmod 660 /sys%p/active_low /sys%p/direction /sys%p/edge /sys%p/value'"

into a udev rule and got it working. Raspbian has this rule out of box, but not Arch Linux.

[dceejay]

@bjo Did you also have to add the user to gpio group or was that already in place ?