How different is the VNCL4040 from the VNCL4000 w/respect to Arduino coding and operation?

Greetings. Several years ago, I wrote a program to do simple readings from the VNCL4000 ( https://www.sparkfun.com/products/retired/10901) using the then provided sample code.

I’m trying to create a couple of duplicate setups with minimal redesign. Is it likely the VNCL4040 would be an easy swap?

https://www.sparkfun.com/products/15177

Also, I’m trying to understand what “smart persistence” means in practice.

Thanks in advance for any advice!

These are two different IC’s. You’ll have to review all the datasheets and specs. If anything differs then you’ll probably want to start fresh. Just be through reading through the datasheets.