Klipper-Firmware: interesting/useful recommendation

[Wick]

Don't know if it's allowed to link to the official Voron-Forum, but I think this is a very useful hint in regarding of Printer security:

pls. delete the Link if not allowed: https://forum.vorondesign.com/threads/psa-gpio-pins-to-set-at-micro-controller-startup.169/

On my Octopus1.1 the hotend fan pin is PE5. I went for this and it works great

[smirk]

There's nothing wrong, per se, with linking to the main Voron Forum (or any other site). The only reservation of putting in links (and we all do it) is when the target link dissappears or breaks then we lose the useful information and simply have a post with a broken link

It's a balancing act really, it is a real pain (and brings it's own maintenance issues) if we schlurp in huge amounts of info from elsewhere but for small tidbits like the one you have found I would just include it. Good find by the way and a really good point. I have just included the relevant info from Duke@VoronDesign Forum:

Quote

I recommend when setting up make menuconfig to build the Klipper firmware to tic the box that says "Enable extra low-level configuration options" and add the pin that is controls your hotend cooling fan to the option "GPIO pins to set at micro-controller startup".

The reason to enable this feature is to prevent jamming your hotend, or melting your toolhead if the controller is reset while your extruder is hot. This can happen after a momentary power outage, or pressing the reset button on your display, for example. After the MCU resets, it will turn on the hotend fan and keep it on until communication with Klipper is reestablished and Klipper has determined that the hotend is cool and the fan no longer needs to be on.

If you have multiple pins that you need or want to enable at startup, separate them with a comma. For example, if you have an SKR Mini E3 V2 (that requires PA14 to be held low at startup) and you have your hotend fan connected to PC7, you would enter "!PA14,PC7". If you also wanted to have your cooling fan that is controlled by PC6, you can enter "!PA14,PC7,PC6". If you want to enable any steppers at startup you can add the enable pins for those steppers as well (stepper enable pins are typically active low so add an exclamation point in front of the pin, just like it's written in your printer.cfg).