So I have the hard part, or so I think, out of the way with a project I’ve been working on. It uses a particle photon that is battery powered and goes under my pool skimmer basket. I have two sensors attached to it one is a ds18b20 temperature sensor and the other is a sonic distance sensor. It wakes up every 4 hours and takes a temperature and a distance reading publishes them to the particle cloud and then goes to sleep. The distance Im using to determine if i need to turn on the water to top off the pool or if the level is okay. The temperature I want to ultimately get into smartthings so that it can display on action tiles or also be used in automations to turn on other smartthings connected devices. It isn’t 100 percent necessary to get the distance meaurement into smartthings but both would be cool too. Perhaps maybe directly to webcore with the distance measurement and into a variable or something so it wont need a device type? What is the easiest way in my scenario with the board only being awake for a short few seconds each day to get this data into smartthings so it can start being useful to me? Has anyone written a device handler for this type of device?
Particle Photon Sensors
I have no experience with sonic distance sensor but have you considered using a leak detector and using it in reverse (wet is good, dry is bad? 
)
That was plan b actually if the sonic didn’t work. However, hardware wise all is working I just need to figure out how to get the data into smartthings.
I checked out their site out of curiosity and it looks like they have an API and webhook for you to access data that your sensor uploads. I am not well versed in json but if one of the @webCoRE_Minions or someone else with json skills reads this post that might be able to help you put together a piston that can query your device in the particle cloud and send that back to a piston which you can then store in a variable or perform tasks on.
I was able to finally figure this out by having an always powered photon subscribe to the events from my battery powered one. I then have smartthings poll the always powered photon for the data. It works flawlessly now! It wont refresh on its own but I have a webhook that fires when the sensor sends new data that through webcore starts a piston to refresh the temp.