Workshop stopwatch

Setup, Configuration and Use Beginners
1

Hello,
I want to build a stopwatch. Unfortunately, I do not know how to do it. The clock should start at a status change. and refresh every fifteen minutes.
I’ve already done a little bit of DIY. But I can not get any further.
I have a switch when the time is up. and the item (stopwatch) should be updated every 15 minutes.
Es soll nur stunden und minuten angezeigt werden. 112std:15min
What I already have:
Item

Switch Gmc_test
Time   Gmc_stoppuhr    "Stoppuhr [%1$td.%1$tm]"

Sitemap

Switch item=Gmc_test
DateTime item=Gmc_stoppuhr

rules

rule "Stoppuhr"
when   
    Item Gmc_test changed or
    Time cron "0 0/15 * * * ?"
then
    val long start
    val long dauer
    if (Gmc_test.state==ON)
    {
        start = now.minutes
    }
    else
    {
        dauer = now.minutes - start
        postUpdate(Gmc_stoppuhr,dauer)
    }
end

I look forward to your ideas.

2

Using this cron job the rule will run every 15 minutes regardless of the switch state.

For a timer you could create a proxy item and use the expire binding.

See my example rule below that uses iPhone detection and the expire binding as a timer. The rule executes when gPresent receives an update. If no one is detected a timer set for 20 minutes is started. After the 20 minute timer expires then Presents will send a command off. If during the 20 minutes presents is detected then the timer is canceled.

If you modify the items and the expire timer, to suit your needs, you should be able to use the rule with a switch as well.

Items:

Group:Switch:AND(OFF,ON) gPresent <present>
Switch Present "Phone is home" <present>
Switch Present_Timer { expire="20m, command=OFF" }
Switch MyDevice <network> (gPresent) { channel="network:pingdevice:SiPhone:online" }

Rule:

rule "gPresent updated, at least one change of state"
when
    Item gPresent received update
then
    // someone came home
    if(gPresent.state == ON && Present.state != ON) { 
        Present_Timer.postUpdate(OFF) // cancel the timer if necessary
        Present.sendCommand(ON)
    }

    // no one is home and timer is not yet ticking (otherwise endless loop)
    else if(gPresent.state == OFF && Present.state != OFF && Present_Timer.state != ON) {
        Present_Timer.sendCommand(ON) // start the timer
    }
end

rule "Present_Timer expired"
when
	Item Present_Timer received command OFF
then
	Present.sendCommand(OFF)
end

Hope this helps.

3

See this thread:
There is a stopwatch: