1kΩ RTD Meat Probe with µC.

Thread Starter


Joined Jun 1, 2017
Hi all,

I have a Traeger meat probe that has a 1000Ω RTD in it that I want to hook up to an AtMega328P to show on an LCD screen. I see many circuits out there, like the MAX31865 and others from Adafruit, but I got to thinking, couldn't I just use the RTD as one half of a voltage divider and just use a precise power supply to make sure the power is always 5.00V ± 0.1V?

Thanks and stay safe,


Joined Feb 24, 2006
I think you want to use a current source, not a voltage source. You want the same current going through the RTD as goes through your reference resistor. Having a known reference resistor with the same current going through it is really handy. You can use a differential A/D converter to measure the fixed resistor and the RTD. Then you can do any correction and linearization in the uC.

Here is an Analog Devices App Note on the subject