The SmartApp code…
/**
* **************** Appliance Finished - Switch ****************
*
* Design Usage:
* This was designed to let me know when the laundry was finished by detecting the power used by a smart socket
*
*
* Copyright 2017 Andrew Parker
*
* This SmartApp is free!
* Donations to support development efforts are accepted via:
*
* Paypal at: https://www.paypal.me/smartcobra
*
*
* I'm very happy for you to use this app without a donation, but if you find it useful then it would be nice to get a 'shout out' on the forum! - @Cobra
* Have an idea to make this app better? - Please let me know :)
*
* Website: http://securendpoint.com/smartthings
*
*-------------------------------------------------------------------------------------------------------------------
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License
* for the specific language governing permissions and limitations under the License.
*-------------------------------------------------------------------------------------------------------------------
*
* If modifying this project, please keep the above header intact and add your comments/credits below - Thank you! - @Cobra
*
*-------------------------------------------------------------------------------------------------------------------
*
* Last Update: 07/09/2017
*
* Changes:
*
*
*
*
*
* V1.0.0 - POC
*
*/
definition(
name: "Appliance Finished - Switch",
namespace: "Cobra",
author: "SmartThings",
description: "Turn on a switch if energy goes below a defined level and stays that way for a set number of minutes (To get 'Big Talker' to announce when an appliance has finished)",
category: "Green Living",
iconUrl: "http://cdn.device-icons.smartthings.com/Appliances/appliances1-icn@2x.png",
iconX2Url: "http://cdn.device-icons.smartthings.com/Appliances/appliances1-icn@2x.png",
iconX3Url: "http://cdn.device-icons.smartthings.com/Appliances/appliances1-icn@2x.png"
)
preferences {
section {
paragraph "V1.0.0"
paragraph image: "http://cdn.device-icons.smartthings.com/Appliances/appliances1-icn@2x.png",
title: "Appliance Finished",
required: false,
"Turn on a switch if energy goes below a defined level and stays that way for a set number of minutes"
input(name: "enableswitch1", type: "capability.switch", title: "Enable/Disable app with this switch", required: false, multiple: false, description: null)
input(name: "meter", type: "capability.powerMeter", title: "When This Power Meter...", required: true, multiple: false, description: null)
input(name: "belowThreshold", type: "number", title: "Reports Below...", required: true, description: "in either watts or kw.")
input(name: "delay1", type: "number", title: "And stays that way for...", required: true, description: "this number of minutes")
input(name: "switch1", type: "capability.switch", title: "Turn this switch on", required: true, multiple: true, description: null)
}
}
def installed() {
initialize()
}
def updated() {
unsubscribe()
initialize()
}
def initialize() {
log.debug "Initialised with settings: ${settings}"
subscribe(meter, "power", meterHandler)
subscribe(switch1, "switch", switch1Handler)
subscribe(enableswitch1, "switch", enableswitch1Handler)
state.enablecurrS1 == 'on'
}
def enableswitch1Handler(evt){
state.enablecurrS1 = evt.value
log.debug "$enableswitch1 is $state.enablecurrS1"
}
def switch1Handler(evt){
state.currS1 = evt.value
log.debug "$switch1 is $state.currS1"
}
def meterHandler(evt) {
state.meterValue = evt.value as double
def currTime = new Date()
log.info "$meter shows $state.meterValue Watts - $currTime"
if(state.enablecurrS1 == 'on'){
checkNow()
}
else if(state.enablecurrS1 == 'off'){
log.info " App disabled by $enableswitch1 being off"
}
}
def checkNow(){
log.debug "checkNow - Power is: $state.meterValue"
state.belowValue = belowThreshold as int
if (state.meterValue < state.belowValue) {
def mydelay = 60 * delay1 as int
log.debug "Checking again after delay: $delay1 minutes... Power is: $state.meterValue"
runIn(mydelay, checkAgain)
}
}
def checkAgain() {
if (state.meterValue < state.belowValue) {
log.debug "Checking again... Power is: $state.meterValue"
log.info " switching $switch1 on"
switch1.on()
}
else if (state.meterValue > state.belowValue) {
log.debug "checkAgain - Power is: $state.meterValue so cannot run yet..."
}
}
As with all the apps I create (related to voice/speaking) the first section has an ‘enable/disable’ switch - I just use a generic virtual switch “Voice Announcements” so I can disable the app at any time. and make the house quiet
I’m sure there is probably a better way to do this but it works for me! 
