add the reverse mode of temperature_fan

[CF3B5]

add the reverse working mode of temperature_fan to some internal circulation heating fans.

Signed-off-by: Locke chen cf3b5bb@gmail.com

[Sineos]

Many thanks for your contribution.
Without judging code or implementation:

• Your contribution needs a sign off line according to https://github.com/Klipper3d/klipper/blob/master/docs/CONTRIBUTING.md
• The setting needs documentation in the applicable sections as well

[claytono]

@CF3B5 I've been wanting something exactly like this. Thanks :)

[KevinOConnor]

Thanks. As a high-level comment, I'm not really sure what this PR does. As a result, I think it will need a reviewer to help evaluate the benefits.

-Kevin

[github-actions]

Thank you for your contribution to Klipper. Unfortunately, a reviewer has not assigned themselves to this GitHub Pull Request. All Pull Requests are reviewed before merging, and a reviewer will need to volunteer. Further information is available at: https://www.klipper3d.org/CONTRIBUTING.html

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[claytono]

@KevinOConnor I think the intent is to use this to control things like under bed fans. You could have a set point for the chamber temperature, then use this to turn the fan off once the chamber temperature reaches that set point. At least that was my hope when I started watching this PR :)

[dingyifei]

Make sure your commit message follow https://www.klipper3d.org/CONTRIBUTING.html#format-of-commit-messages

[dingyifei]

You need to mention the default is False

[github-actions]

Unfortunately a reviewer has not assigned themselves to this GitHub Pull Request and it is therefore being closed. It is a good idea to move further discussion to the Klipper Discourse server. Reviewers can reach out on that forum to let you know if they are interested and when they are available.

Best regards,
~ Your friendly GitIssueBot

PS: I'm just an automated script, not a human being.

[kmobs]

I'm a big fan of this. Works really nicely for adding a chamber heater as well.

[Henlor]

Really nice feature! I'm hoping it would be implemented :)

[dingyifei]

Any update on this PR's status?