I have an idea that involves detecting and possibly measuring a 12v feed from a car but my electrics skills are a little limited and I'm using this idea to learn. My understanding is that the 12v feed could range from 11-18v so I'll need some sort of step down electronics. So this is my understanding
If I use a regulator LM1117 to 3.3v this will provide a basic high/low feed. If this is correct this could then be connected directly to a GPIO input.
Use some other form of step down electronics (I need ideas or documents) that steps down the max 18v down to 3.3v. As the input voltage drops lower so does the output voltage. Then I can use an MCP3008 device to the read the actual voltage.
So is my thinking about both options correct and which would be the best approach? Technically is the regulator that I've referenced in option 1 the best option? If Option 2 is viable can anyone suggest any reference documents that I could read that provides the required stepdown.
This is as much a learning excercise as a real project, so the solution has to be reasonably simple and relatively cheap. Even though I've only mentioned one 12v feed eventually there will be 8 feeds two of which will be pulsating on and off. I'm using a PI and have RasPIO Zero on order:
Thanks for any help
Thanks for your help, I'll be doing a little testing over the weekend, as a result of your suggestions I've found a couple of useful site (very basic but what I need):