Serial Transmission Suddenly Gets Delay

madscience2728:
Data will be printed and received every fifty ms.

But unless you changed the data type for lastSample, after 30 seconds or so (or whenever millis() first returns a value larger than an integer) the Arduino will NOT consistently be sending every 50 millis.

I can't see how that wouldn't have an effect.

Just trying to help,

Brad
KF7FER