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Re: how to calculate equations to log 0-5v sensors
Posted: Mon Oct 09, 2017 4:43 pm
by delcowizzid
Was getting 65psi with no pressure
Re: how to calculate equations to log 0-5v sensors
Posted: Mon Oct 09, 2017 4:53 pm
by The1
should be around 14psi then i would think. Maybe their specs are wrong, perhaps check the voltage with a DMM to double check.
Re: how to calculate equations to log 0-5v sensors
Posted: Mon Oct 09, 2017 10:03 pm
by delcowizzid
think its good enough to test with pressure sits at 0.12psi with no pressure can do 1.68psi by mouth which is close to what a human can do adx is all setup including history table for backpressure will try it out this week with an aircompressor and gauge setup to see if its close or way off.i think the ose$12p wiring pinout doc is wrong or the adx was wrong cause im hooked to b12 which is spare/extra map for baro but the list view was changing data in the cranking time counter which the doc says is actually pin B2
Re: how to calculate equations to log 0-5v sensors
Posted: Tue Oct 10, 2017 9:30 am
by VL400
The calc is (X / 1.18) - 21.75 for the 174PSI sensor on a 0-5V input and 8bit resolution. With that sensor you get only slightly better than 1 PSI resolution though, 0.85PSI
The cranking time item is no longer valid, it was removed in v1.11 as it was unused and got me 1 byte of RAM. Id say its an ADX issue.
Re: how to calculate equations to log 0-5v sensors
Posted: Tue Oct 10, 2017 1:43 pm
by The1
doesn't that calc workout to 21.75-194psi? or is it not 0-255 count?
Re: how to calculate equations to log 0-5v sensors
Posted: Tue Oct 10, 2017 3:11 pm
by VL400
The sensors are not 0-5V, they are 0.5-4.5V.
Re: how to calculate equations to log 0-5v sensors
Posted: Tue Oct 10, 2017 3:29 pm
by The1
right you are!
Re: how to calculate equations to log 0-5v sensors
Posted: Tue Oct 10, 2017 4:05 pm
by delcowizzid
Thank you very much lol.how do you do the maths to work it out vl400 I'm sure others would like to know how to calculate these things like I would .I'm gonna be doing it all again when the 0-100psi sensor shows up .is the calc different on the b2 line being able to read higher volts and what's the resolution difference. If resolution is not gonna be great I'll just use b12 and log fuel psi or backpressure one at a time I don't need to log them all the time anyway once I have data
Re: how to calculate equations to log 0-5v sensors
Posted: Tue Oct 10, 2017 5:45 pm
by VL400
On a piece of paper

But here you go, just put this together which might help for your other sensors.
Edit: See the next page for the fixed version ..
https://pcmhacking.net/forums/viewt ... 249#p82249
Re: how to calculate equations to log 0-5v sensors
Posted: Tue Oct 10, 2017 6:00 pm
by delcowizzid
now that my friend is very bloody cool LOL