Fix for #3955: added a delay after switching relay

[DedeHai]

helps to stabilize power on the LEDs before sending data

[softhack007]

Looks OK to me.

@DedeHai did you check that the delay is only happening once when the relay actually gets switched?

The relay handling code is very old (=hard to read) - a repeated digitalWrite of the same value would not be noticeable, however a repeated delay might hurt ...

[DedeHai]

the code is only executed once when exiting offmode: at the end of the function, offmode is disabled.

[softhack007]

👍

[softhack007]

@DedeHai on a second look - do you think that the same delay should also be added at startup when initially controlling the relay? If yes, then maybe this location should also be changed:

WLED/wled00/wled.cpp

Lines 590 to 593 in bb0c0af

	if (rlyPin >= 0) {
	pinMode(rlyPin, rlyOpenDrain ? OUTPUT_OPEN_DRAIN : OUTPUT);
	digitalWrite(rlyPin, (rlyMde ? bri : !bri));
	}

WLED::beginStrip() runs once at startup, long before handleIO() gets called for the first time.

Just a random after-merge thought. Could be I'm just not involved at discord so I missed something important 🤷‍♂️ ...

[DedeHai]

I thought about that too, but I have noticed recently, that there may be a bug in that part of the code and I wanted to take a closer look at: I did notice in a test, that the relay did not always switch to on depending on config settings and preset settings.
in addition (unrelated): I would like to change the "orange color" behavior at bootup: if there are more than 1 segments, it is impossible to get anything else than orange on the higher numbered segments, which actually puzzles me that there was never a request to change that. or it may just be me: I always shut down my lights with a hard switch rather than putting them in standby, so this behaviour of orange at bootup is annoying.
I have a branch with a fix ready for PR with only one downside: if a new segment is created, it will be black instead of orange, to keep that, the web UI would need to set it so as WLED cannot know if a segment is new or if it changed from a preset.