Making the move to millis()-based code can be daunting. You have to rethink your logic, implement flags, program a state machine — and more importantly, start using millis(). Generally in forums and on IRC people will just point to the “blink without delay” example, hoping the commented code is enough for a new user. It’s not enough.

I have a growing list of millis()-based tasks posted in my millis() cookbook. But sometimes that those examples might be too simple or not close enough to your project’s end target. That got me thinking about different ways to help explain how millis() works. I thought “wow, you need to understand every line of an example” which leads me to: line-by-line.

Give this “blink without delay line by line” tutorial a shot if you’ve had trouble understanding other millis() examples.