@snowcrash said in Duet Wifi 2 third party pt100 board:
@crazyjane, to the best of my knowledge, one important point to bear in mind in this context is that the 3rd party board needs to have a 400R reference resistor for the board to work properly (i.e. give correct readings) when hooked up to the Duet.
Based on the schematics, 400R is the value of the reference resistor on the Duet's daughter board (although in some cases it's noted as 430R - don't ask me why), and, again as far as I know, that's the value used by the Duet's firmware (unless there's a way of tweaking this value in the settings - I haven't looked into that).
For my machine, I've actually made my own custom little daughter board for the PT-100 based on the MAX31865 & a 400R reference resistor (I didn't want to use the Duet's as I didn't want the daughter board to sit on top of the controller), and it works great 🙂
Hope it helps.
SnowCrash
It's possible to use 430R or another value for the reference resistor instead of 400R, if you specify the value of that resistor in the R parameter of the M305 command.