Try again to open device files on OS X when they are busy
Try again to open device files on OS X when they are busy

On El Capitan (and maybe before), opening a serial device just after it
appears can fail with EBUSY. Just try again after some time.

Koromix/ty,Koromix/tytools,Koromix/tytools,Koromix/ty,Koromix/tytools,Koromix/ty