@Rongzhong LiI‘ve followed the instructions but got the same result. My bittle works on ir and serial port. I tried another iOS app Code&Robots and it works. I am using iphone7p with software version14.8.1. Same situation happened on Android phone. My Nyboard version is v1_1

@Rongzhong Li official code means OpenCat.ino? I’ve tried that already.