Hi, the link for the pro-micro is this Pro Micro - 3.3V/8MHz - DEV-12587 - SparkFun Electronics
You were probably thinking about the pro-mini, very similar name.
I know for sure that as soon there is something in the serial port the sensor has sent it's contents, thats why i have it reading this way.
The sensor sends it's string of bytes, every second while it's being shaked, banged, etc, any movement will trigger it.
When i walk away then the serial comms start breaking up and the array might get filled with "garbage", then serial number check kicks in and the unlocking fails, when i'm a certain distance away then the serial comms are severed and -1s start coming in and the lock function is called.