dave-in-nj:
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my request was because I am trying to figure the most rugged, low cost, reliable, temperature sensors, and 2-3 degrees is fine. 'calibration' of often putting all the sensors in the same duct, running the fan and setting them so they all read the same at some common point, like room temperature.I am looking at RTD's for their simplicity and ease of use. the MAX6675 caught my eye as it offered no need for fancy math, was just a library function and was serial input. so my 5 temp sensors was no big deal.
Add a current sensor and such and it is simple enough for a NANO to handle.
Take a look at this article if you like on using an ESP8266 and it's analog input. I used 1% resistor for the voltage divider and a quality Vishay thermistor. I do now have in the lab an NIST "traceable" digital thermometer (+/- 1C) that I have used with the ESP8266 temperature probe and I'm showing a +/- 1C in the 50F to 90F range ... which is all I wanted for the air handler in the HVAC I am monitoring.
Ray