Is pullup resistor needed for temp sensor on ADC 6-7 ?

[oldskool]

Hi, wanting to datalog intercooler water temp with AEM sensor 30-2012, AEM has 1/8 npt & spec sheet that I need. I did 3.0 board mod for ADC 6 & 7 inputs as my MS3X inputs are already used. Are pullup resistors needed to add this 2 wire temp sensor and 3rd oxygen sensor, or any other 0-5v inputs? Can I get 5 volt power from TPS VREF circuit for these added sensors?
Thanks.

[elaw]

Pullup resistors are almost always required for thermistor-type temperature sensors, and you could connect the resistor to Vref.

Your third O2 sensor... is it wideband or narrowband? Wideband sensors have their own separate power and do not need a pullup resistor (never connect their power feed or ground wires to the Megasquirt). Narrowband sensors are a special case and I think would usually have a 1 megohm resistor pulling them to ground.

[oldskool]

Pullup resistors are almost always required for thermistor-type temperature sensors, and you could connect the resistor to Vref.

Your third O2 sensor... is it wideband or narrowband? Wideband sensors have their own separate power and do not need a pullup resistor (never connect their power feed or ground wires to the Megasquirt). Narrowband sensors are a special case and I think would usually have a 1 megohm resistor pulling them to ground.

Yes, my 3rd o2 is wideband, forgot they had there own power. So I have to run a resistor between VREF & temp sensor, then other sensor wire to ADC at MS3? How is a pullup resistor wired, can it be wired outside of MS3?
Thanks

[elaw]

Electrically, inside or outside the MS would be fine. Mechanically, inside would be better since it would be one less "thing" with junctions in the middle of your wiring harness. But if done carefully, outside would probably be okay.

[oldskool]

Electrically, inside or outside the MS would be fine. Mechanically, inside would be better since it would be one less "thing" with junctions in the middle of your wiring harness. But if done carefully, outside would probably be okay.

I took this part out of MS3 schematic, would this be a correct pullup circuit for aux temp sensor? Thanks

[racingmini_mtl]

would this be a correct pullup circuit for aux temp sensor?

Yes.

[oldskool]

Thanks, appreciate all the help.

[Baxsie]

. . . datalog intercooler water temp with AEM sensor 30-2012, AEM has 1/8 npt & spec sheet that I need . . .

Were you able to make the temperature data from the AEM sensor 30-2012 show up as degrees F or degrees C?

I have my AEM 30-2012 connected and get the correct raw ADC readings, but I cannot figure out how to tell MegaSquirt hardware and software how to convert it to engineering units.

The most helpful suggestion I have had (ref: http://www.msextra.com/forums/viewtopic ... 31&t=58839 ) is to switch to a sensor with the GM curve, but it really seems like it should not be so hard to add a new sensor curve.