CAN node for pre-1996 Vehicles
 

Speaking of the "ScanGauge." I was wondering if anyone within range had any information that might make it possible to build a device that could efficiently become a virtual OBDII connector point/port in pre-1996 vehicles--thereby allowing the user to connect a ScanGauge type device to it and access a small subset of information normally available.

In other worlds, based on recent experience, I think I can create a suitable device interface for acquiring fuel/distance information. I could also, conceivably, handle the task of building the (CAN) Controller Area network node interface--i.e. meeting the electrical and basic interface specifications for CAN. That part does not seem too hard.

However, once the interface is created, I have no way to know exactly what inquiry messages from the scan gauge would need to be responded to---and the necessary format. So on the off chance that someone has intimate knowledge of the Scangauge message format etc, and wishes to share it.. I make this inquiry.

That makes the scangauge a very expensive lcd display. Why bother with the obd translation? Just connect whatever you want to monitor to a mpguino hybrid using the analog ports and display it.

Yes, it does make it more expensive. Besides the technical challenge/enjoyment involved, if someone already owned a "ScanGauge" for one vehicle, it would be nice be able to use it (more) universally. In other words, in our family we have one ScanGauge-capable vehicle, and two which are not. At any rate, I am only thinking about it-for now.

LOL, For the price of one sg you could put mpguinos in all three cars :) The injector monitoring approach is typically more accurate than obd solutions.

I think there is a version of the megasquirt that has obd, but if you can build a megasquirt, you can modify that to display mpg on something (like a $15 serial lcd).

But take a look at the obduino, http://ecomodder.com/forum/showthrea...auge-2702.html , it is a mpguino like self contained computer (atmega and an lcd and some buttons) that can read some obd protocols. You can see what pids it uses to determine mpg, as well as the messaging details.

"Well... you see--- i am new to these parts." So, any "unbiased" opinion/information I receive could be useful. Does anyone know exactly how many SGs have been sold?

I am merely stating the bleeding obvious from much experience. The obd market is for people who don't like tapping wires on their car, your adapter would require them to do just that. Nothing biased about it, this is a half baked idea. Have fun.

Well thanks for your feedback. I am encouraged.

c'mon now, put your mad skills to some good use :)

You know there has to be something that people need, how about a diy efie? That intercepts a narrow bandwith o2 sensor and adds a user controlled delay to lean out the mixture (based on conditions, could even leverage obd for all the sensor values if needed)? maybe with injector pulse feedback or somethin?

I dunno, just trying to think of something that might have a demand and be productive.

Not much diy in the fine tuned water/methanol injection department either.

An although we have diy mpg gauge out the yang, there are some useful features that no-one has sorted out yet:
two that come to mind are cDA computing and determining the most efficient acceleration curve.

You have given me an idea, We should probably start a diy wishlist.

Well yes.. the future usefulness of this approach does not preclude reading any of about four (scaled) analog parameters from the vehicle--and relaying the values back to the host computer. While it does NOT currently have analog output capacity--- that could be rectified. Those analog inputs could also be used to interface with accelerometers---devices that might supply useful parameters for the "arithmetic" you suggest.

accelerometers are nice, but I would start with the vehicle speed sensor as it is far more accurate, and (I think) we are mostly about cheap here :)