New user desperately needs help


Hello I am a new user who cannot get a piston to work.

I have installed webcore on my ST app on my phone.

first I followed the directions per the video and the app did not give me a code to register my browser. How do I find this code?

second I have tried at least 10 times to make a basic piston. if my temp is below 80 degrees F (current temp on multi sensor is 70 degrees f) on my multi sensor turn on a light. The current evaluation states that it is true but the light does not turn on. If I look at my dashboard is tells me that one piston is running and that the piston uses 1 condition and has subscribed to 1 device. should is say anything about the action?

Please someone this can be this hard I desperately need some help. If I can’t get this to work I’m going to send all the stuff back.

If this is not the correct category please let me now and I will correct the error.


Go to “Automation” in the SmartThings app –> webCoRE -> “Register a browser”. That will give you a code to log into webcore.

There are many examples here of this application. Just click on the magnifing glass above and do a little research. Basically, you are going to do…

IF Temperature_Sensor drops below 80 degrees
    With Light
      Turn On.


or the new ST app, go to the menu (three bars in the upper left of the screen), choose SmartApps and then your instance of webCoRE :slight_smile:


@Pantheon @jkp

Thank you for your help! I deleted the entire program and reinstalled. The Wiki that I was using instructed me to install CoRE not webCoRE. I installed WebCoRE and I was able to get the code to authorize my browser. @Pantheon thank you for the sample program I will give it a try. I was trying to keep it simple for my first program and getting really frustrated. Ultimately I want to program a temp receiver and a plug to keep a room warm in the basement using a little heater.

I am excited to be successful with this platform and program. Maybe now my piston that I make within the SmartThings App will work.

Thank you again. You have brightened my week that has been a little dreary this week.


This forum is literally FULL of people who will assist you. Just ask.


I just need to find my way around a little, understand the categories and where to post questions. I will definitely search before I ask because I’m sure I’m not the only one to have noob questions. :grinning:


@Pantheon okay so this is where I’m missing something. Below is the program I wrote my sensor is below 80 degrees F but my light will not turn on. If I test the program the light will turn on. What am I missing?


That piston will execute whenever the temp changes on Sensor 2. (or you press Test)
At that time, if it is less than 80, the command is sent to Switch 3.


Does the temp have to change? Or should the light come on because the temp is below 80 degrees?


It has to change… (or you can manually query)

WebCoRE is event driven, meaning: “When X happens, do Y”


@WCmore Thank you for that bit of information several things have become clear now!

I wanted to see if the piston worked so I put the sensor in the freezer. As the temp fell the light came on. That also explains why last night as the house cooled the light came on and I could not figure out why. I have some thinking to do now!


For a “less frequent” trigger, this concept works well:

IF Sensor 2's temperature DROPS BELOW 80
    Then Turn on Switch 3

This one only triggers once as it crosses the threshold. (in this case, from 80 to 79)
It will not fire again until it rises to 80 (or higher), and then drops below 80.


If you are going to power a space heater I would add additional safeguards into your piston.

Maybe setup up some time constraints. A do every 10 minutes and check the temp. As WCmore mentioned webcore is event driven. So if your temp goes above the shutoff temp for whatever reason, loss of internet someone accidentally turned it on manually while above the threshold. I have also had switches turn on by themselves for no reason. It is a rare occurrence but it does happen. You can find a few threads about it.
The heater may not get turned off if you are only relying on a temp change. If it gets turned off and doesn’t come back on that’s an inconvenience, if it gets turned on and doesn’t get turned back off that can be a bigger problem.

I had a similar issue a few years back when I wrote my first smartapp. I had a app to heat our master bath every morning just before we got up. For the first couple of days I couldn’t figure out why it wouldn’t come in the mornings. The temp was below the threshold, but as you found out it needs to cross that threshold. So I added a time activation to check the temp at 5:00 am and then I could start the process.

This is how I found out about switches turning themselves on. One morning at about 3:00AM the receptacle that powered the heater came on for no reason. This was after I had been using it for a while and had learned to put in safeguards. My time constarints turned it back off. I contacted ST support about it because it concerned me why it came on and they basically said yeah that happens sometimes.

The switch turning on is also an event, so you can trigger off of that as well. So if someone turns it on manually you can check the temp or time. I also had a check to verify the door to the bathroom was closed. If anything is a amiss you can turn it back off. Just things to think about.


Thanks for the tip now I just have to figure out how to program all the safe guards you have mentioned.

When I was experimenting with temp less than last night it did not cross the threshold and turned on.

The way I I stand how it worked I’d like this…the piston did not understand where the temp was because there was no change in status. The initial temp on the multiswitch was 70 degrees worth the threshold at 80. I put the switch in the freezer and as soon as the temp dropped from 70 to something less the heater turned on. My understanding is there was not a change even though it was below 80. As soon as it changed it realized the condition was not met so it turn the heater on.


Yes. “is less than” will be evaluated whenever the device reports a temperature change.
(or you get impatient and press Test)

The exception to my earlier statement is if you edit the piston while it is already true. Then, yes, a new temp change must come in before it is evaluated. (in your case, it was 70 to 69, but 70 to 71 would have also worked)

If you are using piston ‘einsv’, then in normal day to day use, my earlier statement is what you will be seeing.

On the other hand, if you are using “DROPS BELOW 80” as your trigger, and you edit the piston while it is 70 degrees, then Switch3 will not be touched no matter what you do until the temp rises to 80 or more, and then drops below 80.


Thus my suggestion “drops below 80” in my first response. :smile:



I’m sorry showing how new I am. What is ‘einsv’ ?


The image of the piston you posted above has an import code printed on it. In your piston that code was einsv. That code can be used to import a piston into your dashboard. So if someone posts an image of their piston, you can import it and select your devices to use in it. It is a great way for users to share their pistons with others.