Only allow switch to be pressed every 30 seconds?

[rlkoshak (Rich Koshak)]

I just saw this solution in another thread which should work for this as well.

Debouncing a switch

I came to this thread on a search for how to debounce an openhab rule, and none of these answers are really “correct” in my mind, so I wrote my own version using locks. This will guarantee thread safety in case rules are run concurrently and is very simple to understand. Thought I’d post it in case other people come to this thread for the same reason. In my case, I’m debouncing a very cheap 433 wireless sensor picked up by rfxcom which often sends 2/3/4 times depending on its mood. State change…

import java.util.concurrent.locks.Lock
import java.util.concurrent.locks.ReentrantLock

var Lock lock = new ReentrantLock()

rule "garage proxy"
when
    Item Garage received command
then
    // tryLock will acquire the lock if it is available, and fail fast otherwise.
    if (lock.tryLock()) {
        Garage.sendCommand(ON)
        Thread::sleep(30000)
        lock.unlock()
    } else {
        logInfo("Garage", "Garage button currently disabled")
    }
end

This uses a Reentrant Lock to disable the rule. A Rule triggers in one thread, grabs the lock, sends the command to the “real” garage switch, sleeps for 30 seconds and gives up the lock. Any subsequent rule triggers while the first one is sleeping will simply jump to the else clause.