BIGTREETECH Octopus V1.1 Question

[lone matrix]

Hello.
Reacently I decided to fix my old 3d printer by changing moatherboard hotend and few other stuff. Now I'm running in issue where I want to add fans for part cooling and my question is, if it is possible to use 4pin PWM fans on Octopus V1.1 and klipper and how if yes.

[sweet lodge]

AI Help

Yes, it is possible to use 4-pin PWM fans with the Octopus V1.1 board and Klipper firmware. To connect a 4-pin PWM fan, you can use the fan outputs on the Octopus V1.1 board. You will need to configure the PWM fan in your Klipper printer.cfg file. You can assign a specific pin to control the fan and set the appropriate parameters for fan control. It's recommended to refer to the Klipper documentation or forums for specific guidance on setting up PWM fans with your setup.

WARNING: This response is AI generated and may contain errors.

[lone matrix]

In offical diagram of board i dont see 4 pin connectors

[sullen zinc]

Nope, 2 pin only

[astral mirage]

Iirc only the pro has a pwm port

[sullen zinc]

also no

At least not the fan ports

Source: I have two

[astral mirage]

Yea youre right

Kraken does

That's what I'm thinking of

But thats a large price difference

You can use the pins on your pi to run pwm tho

[lone matrix]

use 12v rail from board and connect pwm to pi or connect power to pi too?

[astral mirage]

Just the pwm signal pins to pi iirc

https://www.reddit.com/r/klippers/comments/ruyjls/guide_driving_a_4pin_pwm_computer_fan_on_the_btt/

[lone matrix]

or do you have reccomendatio nfor good 2 pin pwm fan, that i cna get in eu or from aliexpress

[astral mirage]

Iirc you can use a mosfet to make a pseudo pwm fan, it's more work tho

[lone matrix]

do pwm ports on octopus allow actaulyl speed controll or are do they only allow ot turn on or off fan?

[astral mirage]

Do you mean the fan ports?

All fan ports allow for control of fan speed except ao fan ports

(The last 2 ports)

[lone matrix]

Ok ty, do I need special 2 port pwm fans or can I sue any 2 port fan?

[astral mirage]

Any fan port, it just feeds it variable voltage

But using voltage to adjust isn't as good as pwm because it's not quite linear, like 10% volts is actually 25% fan speed

50% volts is 70% fan speed

[lone matrix]

sure bit it will give me much less issues right?

[astral mirage]

Oh for sure

Pwm fans aren't worth it for most people lol

[lone matrix]

ty

[sullen zinc]

Thats not how it works on the board

The mosfet switches the fan on and off rapidly

@lone matrix

Its true pwm

[astral mirage]

Oh really? Is that true for all boards or just higher end ones?

[sullen zinc]

All boards

[sullen zinc]

Its probably more effort to create a variable voltage circuit than to slap a mosfet on there

[lone matrix]

Doesn't pwm on bord itself variate voltage? For speed controll

[sullen zinc]

https://en.m.wikipedia.org/wiki/Pulse-width_modulation yall need to read what pwm is