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The Duet allows you to use a PT 100 rather easily with it's daughter board. Right now I'm looking at putting the accelerometer board from a HE280 on a E3dV6 and using a PT100....

Until I remembered that the HE280 uses one of the thermistor terminals as a ground.

So.... How do i make this work?

Add an extra wire or two. There is no reason to only use the 8 pin HE280 connector. And move ground to a different connector or even the ground terminal itself.