Duet3 and Hotend fans on reboot



  • So, I power my pi off of my duet3 currently, and it's troubling that when I reboot the pi there's a long delay while it boots before the hotend fan turns on. I know I can set the pi to be externally powered, but still, there will be that chance of a reboot while my hotend is at temp. What is the best option for dealing with this so we don't get heat creep during reboots?



  • I think there'd need to be some sort of "config-startup.g" on the Duet3's sd card with basic settings like the heaters, fans, thermistors, etc. The firmware would have to look for that file, execute it, then wait for a new config from the SBC. @dc42 ?



  • From power on to fan running is 19.5 seconds on my machine. Duet 3 6HC, two 3HC expansion, Pi 4.

    This strikes me as a non-problem.


  • administrators

    It's also worth mentioning that the Duet 3 will keep its config.g parameters while the Pi reboots. When that is the case, the Duet 3 remains functional quasi-standalone mode with the previously processed configuration. If waiting 20s after a hard power failure is an absolute no-go, perhaps it is a better idea to use always-on fans or even a small UPS.


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