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Cheap way to connect EGT to ECU

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Hi everyone,

I've been searching for a way to connect one k type thermocouple sensor to my AEM Infinity 506 and, to be honest, the found options kinda feel unnecessarily expensive to me(and I've reached the budget limit of my build long ago, since I'm a student).

Apparently there are quite a few cheap "thermocouple amplifier" when I search ebay, but all of those just create another voltage output - which, as I understand it, my ECU cant measure, right?

Is there then actually a way to get this right, without spending hundreds of $ for a EGT CAN/BUS module?

Thanks for the help David.

Does that mean that the "12 bit A/D, 100K pullup to 5V" Pin can be used to measure a voltage between itself and the sensor ground?

I thought that it would create its own voltage and that adding another source of voltage would cause issues with the common ground of the other sensors.

The units from Exhaust Gas Technologies work well, and I can also recommend them, but they must be making a killing on them! I've pulled one apart before to see what IC they use, and they have around $5 worth of components in there, including the PCB.

https://www.adafruit.com/product/1778

Those use an updated version of the same IC. Their documentation says it'll measure from -250degC to +750degC, so its not quite in the range you might want... That range is set by a resistor divider on the output side of the IC, and if you contact adafruit, they might be able to swap the resistors out to get you the full range of a k-type thermocouple.

G'day David, Yes, I completely agree (not about the $100 worth of books...) and I've always had good experiences with Exhaust Gas Technologies and the products they sell, but the thread title is about a cheap way to interface a an EGT sensor to an ECU, and there are cheaper options than the ExGasTech one.

Zac, which options are you thinking about when mentioning alternatives to the EG-Technologies product?

Im not looking for something with a huge spectrum and deadly accuracy.

It would suffice me if I could measure 780-930degC with an accuracy of 20degC.

Edit: Nevermind, didnt notice your first of your two posts. Will contact adafruit. Thanks!