Ok so the title may sound confusing so let me clarify. I have an arduino board and I want to read raw analog data from the car to it so that I can get digital values for my rpm and honestly I don't even need the actual rpm, just the range if that makes sense. So say when the rpm is at 1000, I get a reading of idk 5323 and when it's at 7000 I get a reading of 8944. I just made those numbers up I have no idea what an actual range would be. I really wish I could get that guy from kpelectronics to help me if anyone knows him. I don't even know if he's a member here. My original thought was to get an ELM-327 wire and mod it to hook up to my arduino and get readouts from it then go from there but I think just getting the analog data would be easier and cheaper. I'm a college student so I can't afford to just buy everything. I've done so much research but have found nothing useful. As far as what I'm using it for, it's going in a custom wheel with an rpm indicator bar much like the ones seen on ferrari's and f1 cars


Thanks for your time!

 

After doing a little more research, I actually found a post from Kevin Pierson on the12volt and he cleared up a lot of things. My readings will be in timing between readings and not voltage, making this a little more challenging. Before I can even look at any of that I still have to find a good tachometer wire. There are many suggestions on this site, what is a solid one for an 04? I am not sure if I have an 04 or an 04.5, can someone help me out here? It would be REALLY great if there was one in the cabin.