I hope you know that the 2 are not properly the same parts, both are 5V regulators but the OKI is switching power supply, while the LM2940 is linear one, the main difference for your use is heat dissipated. Is your automotive environment 12V or 24V ? In second case the OKI is highly suggested.
The environment is normal automotive so 12v but more likely over 12v I planned around 12 to 30v to be safe. Yeah I learned that the OKI was a switching regulator after the fact. At the time I bought them I needed a good regulator and was suggested the OKI.
Now that I have built it and it works I got rid of the arduino for a straight atmega328p-pu and wanted to see what else I can do to clean up the circuit to make it cheaper and better understand what I’m building.
The current requirement is super low as I am only powering the 328p at 8mhz internal clock and 2 mosfet that are used to ground the 12v source to turn on the LED’S.
I appreciate any input. I’m just trying to learn I want to use the most adequate parts not looking to over build just because, but I want to make the right choices since I might end up building stuff for other people later on and don’t want them to have stuff die because of crappie power regulations…