Play once, then trigger relay pin?

Hi.
I’m trying to build something that will play an animation exactly once on power up while pulling the relay pin high, then pull the relay pin low. The reason being, I’m trying to run the circuit off a small battery and I’d like to use a soft latching circuit to enable power to the entire circuit, which will remain powered as long as a pin is held high, and turn off completely once the pin is pulled low.
Is this possible with WLED?

You can use a startup playlist to do this.
Add a single “On/Off” style led to your WLED config.
Attach your relay (or 3V compatible circuit) to the GPIO for this new LED.
Create a playlist that turns this single LED On/Off as required before and after the preset with your required animation/effect.

Ah… that’s something I didn’t think of. I’ll give it a try… thanks!