OK, I bought a SmartThings Arduino shield from the SmartThings store. I mounted it on my Arduino and it connected fine. Good so far.
I removed the device from the app to make some changes and try connecting it with a custom device handler. Now the app never sees it again. I have tried resetting, powering everything down and reconnecting, wiping all code off the arduino and reloading. I am at a complete loss.
I have run through debug steps in the Arduino code. I can see that the shield is joining the network, It receives messages, I just don’t know why it never seems to connect via the App. Anyone have the same experience - any advice?