Logging multiple sensors over serial connection?

Hey Guys,

At the moment on my car I only have one additional sensor (wideband AFR) that I am using the serial data output from for logging purposes. At first I thought this was kind of a PITA since I have to have a 2nd cable in addition to the cable I already have for logging all ecu params out of the tactrix, but after reading about some of the issues with hijacking 5v ecu connections to integrate external sensors into the data output via the OBD2 port... it is kind of nice not having to worry about ground issues, offsets, etc.

Anyhow... as I'm looking at doing some more extensive mods it seems like it would be prudent to add some more sensors so I have a more complete picture of what is going on with the car when it comes to things like oil pressure and fuel pressure (or anything else you might recommend?).

My question is though... If I had 2 or three more sensors, can I run all of them through the same serial RS232 by just plugging the single serial pin output from the sensors into different pin locations on the RS232 cable/adapter? Or would each sensor need its own RS232 cable/adapter?

Obviously the latter would kind of suck and if its not possible to run them all through a single serial cable I'll look at taking advantage of some 5v inputs in the harness instead? Are there other options Im not aware of instead?

Any input appreciated.

If I remember correctly, you're working with a stock Subaru ECU and open source tools. COBB has a flex kit that adds fuel pressure monitoring without loss of any inputs, but I don't believe open source has something like that, and I don't believe either lets you insert various sensor data via serial besides the wideband.

You could log additional sensors with an external logger, but then you're dealing with multiple logs and trying to determine how they line up. I've used an OBD2 splitter and set the external logger to receive only, allowing the laptop to request OBD data, then use RPM etc. in the external logger to help line the logs up, but logging is one of the areas where standalones really excel.