Designing an Engine Oil Temperature Display Gauge Project

[GoldOxide_imp]

As for the original idea, spent a few hours measuring the CB's (at least, my CB's...) built-in EOT sensor. The devil is in the details: if the same electronics are to be applied to bikes of different manufacturers, models or even model years, there has to be a guess made on which NTC thermistor is being used. Supply voltage might be different too - just too many variables I'd be comfortable to work with. There are some 50 or so standard NTC series, not sure if I could get a reasonable readout just by guessing. Of course it could be fine-tuned to any specific bike, but that would require some way to input points of the characteristic curve - basically, taking the EOT sensor out, dipping in a cup of hot water, and measuring temperature with resistance changes as the water cools down to room temp. Not something I'd expect to be a standard installation step

Not to complicate the plan, however, if things like these are a common challenge across bikes, one could consider creating a "common" module where generic I/O is wired to, as well as Vcc and ground. Add a low-cost bluetooth radio and broadcast the raw I/O digital values to a receiver module or phone app that will map the I/O to specific device profiles and display their real-world values - refreshing maybe every one or two seconds.

Since you are only reading the I/O and not controlling anything, this should be completely safe. This would be similar to an OBD device (but read-only), and wiring would be flexible to the end user's need.

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You might be able to cobble together from off-the-shelf sources a low-cost common I/O module (4 port enough?), a bank of cheap ADCs, maybe a low-end MCU, integrate a BT radio and that will allow you to focus your energy on the your receiver module, or just a phone application.