Designing an Engine Oil Temperature Display Gauge Project

[Csory_imp]

Since this is the original thread with hooking into the factory EOT sensor, I'll split my gadget project update and post oil temp sensor related info below.

Pulled the sensor from my '18 EX to verify characteristics:

- ECU voltage measured as 5.01V, a very precise 5V source indeed.

- "Pull-up" resistor of the EOT sensor is 476.5 Ohms. I'll take it as a 470R (measured in divider with a handpicked 10k). I guess this is (and was) standard across the entire CB range over the past years, but would be nice if other forum members could check with theirs...

- Sensor element is Bosch NTC M12. Measured at a few points from 253K to 383K and I'm pretty confident this is the exact type. These are widely used and homologized in racing environment, and have approved characteristics up to 433K when used in "H" variant. It means that an excellent Steinhart-Hart fitting is possible across a 200K wide temperature range: [url=https://www.bosch-motorsport.com/media/downloads/fia_formula_3_single_system_16.pdf]see this catalog for details.

- Once being there, spliced into the sensor cable and decided to add this "analog signal sensing" capability to the next iteration of my gadget. Credit goes to Alain for being persistent with the idea