I don't have an answer for this, but I too am interested in understanding how to receive information back from the Photon and into SmartThings so I can trigger other actions.
My use case: I am using the Photon to control the opening and closing of my blinds. It works great and I've integrated it with SmartThings. The Photon shows up as a "Thing" in SmartThings with a device handler that I modified from other examples. I can open and close my blinds successfully using my SmartThings app and even trigger those actions based upon other actions in the home - like motion, temperature or switches being turned on or off.
My hope is that I can figure out how to now capture info that the Photon is collecting and send it back to SmartThings. For example, I have a photoresistor in my setup that closes the blinds if the sun is too bright. I'd like to be able to use the light measurement from that photoresistor in SmartThings to trigger other actions - like possibly turning off lights or changing the airflow in my HVAC. Heck, it would be fun just to double check when the weathman says it is sunny out and to simply look on my phone in my SmartThings app to double check if he's right!
I have tried to use the few, older examples I've found on this site, but they aren't working. Has anyone been successful in doing this? Thanks in advance for you help!