In a small project that I'm working on right now, I have an Arduino Nano that is supposed to get data from various sensors. Now one of the sensors (or rather, 'input') is directly coming from a car. This is supposed to be an Analog input.
The values from this input range between 0V ~ 12V as expected. However, the voltage can surge to upto 30V during ignition.
What I want to do, is implement a small circuit that will "cap" the voltage at 12V. I was thinking of using a Zener diode rated for 30V. Will it work (or am I thinking right)? And what would be the best way to go about this?
Furthermore, I would also want to implement another circuit to proportionally change the 0~12V input to 0~5V input.
Any help would be greatly appreciated!