I have a Duet 2 Wifi running off 24v and would like to connect a fan to P2 to cool the board when the MCU temp gets above 45 degrees. Is this as simple as connecting the fan (a 2 wire 24v fan) to P2? If so, what gcode command do I use to monitor the MCU temp so it knows when to come on?

I have read some posts that talk about having to use a resistor, but am confused about this as the part cooling and heater fans don't need one to operate?

Yes, you can do that. In RepRapFirmware 2, virtual heater 100 is pre-configured to read the MCU temperature. So you need only use the H and T parameters in your M106 P2 command to command thermostatic operation, see [duet3d.dozuki.com]. For example, M106 P2 S1 H100 T45.

You should calibrate the MCU temperature, see [duet3d.dozuki.com].

Edited 1 time(s). Last edit at 09/16/2019 05:43PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].