I have 4 Cores (and 2 Photons). I unclaimed one of my Cores, and did a factory reset, and sent it to a friend to let him play around with it. Unfortunately he never found the time to use it, and returned it to me. He never claimed it.
When I plug in the Core, it blinks Blue (“listening” mode). However when I attempt to use the Spark Core app on my iPhone to claim and set it up, the app is unable to find the Core. I’ve tried all sorts of resets and modes. I’ve also verified that I’m on my 2.4 GHz.
All other cores are connecting to my network just fine.
In all honesty, the configuration process of the Core is a bit shady. That’s the way the TI part was made, and there’s little to be done about that. I think it might be easier to use the CLI, or even a serial terminal to configure it if the app is failing.
With the CLI, you’d use particle setup, particle setup wifi or particle serial wifi. Then go through the prompts.
With a ‘normal’ terminal (putty for example), you’d press “w”, and then follow the prompts. Going this route, you will need to claim your device manually. Press “i” in the terminal to get your DeviceID. Then enter that in the web IDE under “add a new device” in the devices tab.