M42 controlled by temperature I don't think this is currently possible, but is there a way to control an output pin (M42) by temperature? What I was thinking of doing was to setup a fan to blow on the bed after the print has finished. It would turn on the pin as long as the temperature of the bed is over a set point. https://reprap.org/forum/read.php?416,722833,722833#msg-722833 Fri, 06 Mar 2026 16:29:08 -0500 Phorum 5.2.23 https://reprap.org/forum/read.php?416,722833,722871#msg-722871 Re: M42 controlled by temperature https://reprap.org/forum/read.php?416,722833,722871#msg-722871 VDX Duet Sun, 13 Nov 2016 18:06:15 -0500 https://reprap.org/forum/read.php?416,722833,722848#msg-722848 Re: M42 controlled by temperature https://reprap.org/forum/read.php?416,722833,722848#msg-722848
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VDX
... I've add some new "M" codes/routines in Marlin4Due for my needs - wouldn't be a problem to add a new one with a "wait until lower than [nnn] value" for an ADC port.

E.g. "M47 A7 S127" for reading the A7 pin and repeat until the read value will be lower than 127 ...

Does the Marlin4Due work with the Duet Firmware or are you saying you could add your functionality to the Duet firmware?

What I am looking for is a way to say "While thermistor X is greater than temperature Y, set pin Z high." Thermistor X is the same one used by the bed.]]> ElmoC Duet Sun, 13 Nov 2016 16:35:52 -0500 https://reprap.org/forum/read.php?416,722833,722846#msg-722846 Re: M42 controlled by temperature https://reprap.org/forum/read.php?416,722833,722846#msg-722846
E.g. "M47 A7 S127" for reading the A7 pin and repeat until the read value will be lower than 127 ...]]> VDX Duet Sun, 13 Nov 2016 16:32:18 -0500 https://reprap.org/forum/read.php?416,722833,722844#msg-722844 Re: M42 controlled by temperature https://reprap.org/forum/read.php?416,722833,722844#msg-722844
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dc42
If you have a spare controlled fan connector on your Duet, you can set up a thermostatically-controlled fan to do that.

I was planning on an A/C fan through a relay, thus the reason for the M42 pin. If the fan would only run at 100% PWM, I guess that wouldn't hurt the relay control circuit. I am only using one of the two fan outputs right now.]]> ElmoC Duet Sun, 13 Nov 2016 16:28:19 -0500 https://reprap.org/forum/read.php?416,722833,722842#msg-722842 Re: M42 controlled by temperature https://reprap.org/forum/read.php?416,722833,722842#msg-722842 dc42 Duet Sun, 13 Nov 2016 16:23:35 -0500 https://reprap.org/forum/read.php?416,722833,722833#msg-722833 M42 controlled by temperature https://reprap.org/forum/read.php?416,722833,722833#msg-722833 ElmoC Duet Sun, 13 Nov 2016 15:43:20 -0500