1984 22R Engine Telemetry Project

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Mar 31, 2011 | 10:49 AM

EngineerDude

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From: Klamath Falls, OR

1984 22R Engine Telemetry Project

Howdy, all! I'm new here, so be gentile.

In addition to the rebuild I'm planning over the summer for the good 'ol '84 Pickup that's been in the family since new, I'm planning on building a system for displaying, and eventually logging (via PC over Bluetooth, or some kind of removable flash-type memory) engine telemetry data.

Data Planned to Poll:

-Engine RPM
-Oil Press.
-Coolant Temp.
-Electrical Supply Voltage / Battery Voltage
-Ground Speed (provided I can find a way to convert from mechanical to analog/digital electrical)
-Helpful Diagnostic Signals (e.g.: Knock, etc.)

The display setup is going to be pretty basic initially, but I may expand upon it depending upon what kind of feedback it gets. Most of the data will be displayed on a 4-line character LCD, with user-configurable readouts (i.e.: you choose what goes where on the screen), which will be supplemented by a wide LED bar (defaulted to display Engine RPM, but also will be user-configurable). Eventually, all this data will be shipped over Bluetooth to a PC for logging, possibly real-time, allowing for easy record-keeping and graphical analysis.

The problem I have right now, is that I don't know anything about the engine sensors' signal characteristics. I've sent inquiries to Toyota regarding DC/AC operating characteristics for the various console gauge senders, but haven't as of yet received any answers. I was wondering if you super-intelligent folk could answer a couple of questions for me:

-What other kinds of functionality should be included? (E.g.: what other engine data elements should I poll, how should I change the interface, etc.)
-How do the various 'senders' work? (E.g.: do they behave like pull-up potentiometers, or use PWM? What kind of line voltages I could expect to see. That sort of thing.)

Any small tidbits of info would be extraordinarily helpful here, since I need to have a final, fairly detailed proposal for this finished by the end of next month (did I mention this was my Senior Project?

).

I'll try and post some mock-ups and pics of one of the prototype boards when I get a chance. Thanks!

Mar 31, 2011 | 11:34 AM

Outsane

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Joined: Jun 2006

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From: San Diego

Congrats... I'll be watching your progress

Many of the sensors are simple resistance based oil/water temp, oil pressure..many of the voltages being sent to the sensors are in the FSM, and the expected resistances..

have a good time... I started doing this as a school project in 1992, did SAE Mini Baja instead.

Mar 31, 2011 | 12:18 PM

EngineerDude

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From: Klamath Falls, OR

Nice! I've been meaning to track down a good FSM-type resource for quite some time. I'll probably pick up a print copy in addition, just because nothing beats a good 'ol paper manual.

In the meantime though, that gives me a bundle to work with. Thanks!