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Old 06-18-2013, 11:21 PM   #13 (permalink)
t vago
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Originally Posted by NachtRitter View Post
Got it... forgot that you'd done some ECM-fooling mods. Since the OBDuino does provide the MAF reading via OBD and can be tweaked to your needs (by modifying the formula and adding a separate injector pulse input, for instance), could that meet your needs? Seems like the OBDuino can give you access to quite a bit of additional data from the ECM that you'd need to manually wire up with the MPGuino.
I thought about modifying an OBDuino to take advantage of the fact that it likely would return both a manifold air pressure value and an ambient air pressure value as PIDs, but that was after I had already received this MPGuino. Interesting problem, indeed.

From what I can see, it'll be a simple matter of soldering in another wiring terminal for the two analog channels of this particular MPGuino, then running the wiring to support the two spare MAP sensors I have laying around (one for ambient pressure, and one for manifold vacuum). Since the MPGuino code (excuse me, "sketch") is written in some variant of C, it should really simple to initialize the analog channels, and convert their read-in values into pressure. Only challenge I see is to write a fairly quick square root routine - apparently, the complete math library wasn't loaded into the MPGuino in an effort to save programming space.
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