We found that when placed under one of our replacement iPhone backs, the tag didn’t read, so we fiddled with tape and paper until there was enough air space between the metallic bulk of the phone and the RFID antenna.
One post-it note and four layers of packing tape later, the tag scans just fine from within the back of the iPhone, even with 4G and wifi turned on.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.