Variable Persistence After Power Loss


Hi, I’ve been storing Hue light state as Global variables to pull from in my pistons. The only issue is I am unsure as to if those stored variables will be blanked to null if my smartthings hub is power cycled or has loss of mains power. Just to clarity, i am using an externally triggered piston to manually capture the state of a light to store them long term and have not set the variable initial state in webcore.

I cant find any documentation or discussion about this unless i’m blind. Any information about this would be greatly appreciated.

Thank you in advance.


I have never seen the data stored in a Global variable vanish unless a piston was programmed to do so, or it was manually changed/deleted.

But, for what it’s worth, if they are blank at the time of power loss, they will be blank afterwards as well.


For power loss I have been using a great piston (written by @WCmore)
Other than that there is an app - I believe came out like a year ago - that returns all your ph hue bulbs back to, before the power outage state. It’s called Hue Power India.

This is one of the rear cases I would use an app instead of a piston IF i didn’t have that piston already written.


What a fitting name since:
“Some parts of rural India experience 15 hours or more a day of power cuts,
while major towns and cities endure blackouts of several hours a day.”

I think it is mostly due to all of the unauthorized home-made rigging…


It could have been called “Hue Power Hawaii” as well:))))))
(We had a weird winter but it’s getting better now)


That reminds me of someone’s desk :joy::rofl::joy::rofl::joy::joy::joy:


I admit, my desk may look a bit chaotic underneath the hood, but all my cables are clearly marked (both ends), are color coordinated, and are organized in customized & discrete channels for the most part.

25+ external peripherals dynamically connected to 4 PCs is not easy to hide, LOL