I'm looking to build a temperature sensing product and want to use a nodeMCU or similar for the MCU module (something with an analog to digital converter), an LCD a PT100 RTD like the one in this photo:
I will need to measure temperature from 200F to 300F approx and I'm trying to find the most cost efficient way to set the PT100 up while still having good accuracy. I've learned some about voltage divider and difference amplifier and such which accompany normal PT100 usage. I would like to spend no more than $7 total on the temp setup, and the PT100 I'm using is already $3 so $4 left to spend on the rest, I'm willing to build some circuits or parts if I have to. to get accuracy within 1 degree F would be nice. Can someone help get me started on the right path? Thanks for any help!
Best Answer
Maxim make a chip for that:MAX31865 Datasheet
There may be cheaper ways to do it, but if your budget is $4 then that comes in about right allowing a few cents for capacitors etc. and should be pretty straightforward to set up. It'll also be very accurate.
Other manufacturers probably offer similar things.