Howto read rpi gpio state after reboot

howto read rpi gpio state after rpi reboot, or howto initiate force read gpio

Make sure the read at start option is ticked

I check this option, but after reboot not work.
Remark: And after deploying not always working.
If i'm change rpi node parameter, then after deploying working, but if i'm only change rpi node place, after deploy not work.
p.s. If I did modified deploy, if full deploy - works!.

Nodered - 3.1.0
node-red-node-pi-gpio - 2.0.6

That is expected. The gpio node will not be re-initialised if you do a partial deploy (unless the gpio node has been modified).

How do you know?

Debug node doesn't leave any payload message. And it has should change svg graphic element color, but it not change, must change to 0-green, 1- red, after rebooting it remains colorless, until the gpio status changes.

at boot time, the flow may start running before the dashboard connects - so the gpio state may get read and sent before the dashboard is listening.

On boot, by the time you open the browser window, the message from the gpio node will be long gone. Configure a debug node connected to the gpio node and select System Console (as well as debug window) in the debug node. Then reboot and open a command window and run
journalctl -b -u nodered
and it should show you the node-red log since the reboot. You should see the debug node output there.

Yes, after boot rpi node read gpio status, but then what would be the solution for me?
I think need force read gpio status, but how? :thinking:

use a change node to set status into a flow variable.
When dashboard connect - use ui-control node to trigger another change node to read flow variable. (I.e. move it back to msg)

hmmm I not completely understand? :thinking:

Which bit don't you understand? See Working with context : Node-RED if it is the use of context that you do not understand.