A fan script for a beginner

[sdetweil]

the raspberry pi does not provide +12v on any pin… only +5 or +3.3v

see https://www.raspberrypi.org/documentation/usage/gpio/

so you will need another power source that you can turn on/off programatically… or have to install a relay you can control via gpio pins… see google search results for ‘raspberry pi relay control’

now… what signal is required on the speed wire?

typically a gpio pin is either on, or off, or transitioning between one and the other.
so, you would need some other hardware to control the levels of this input to the fan

see google search results for ‘programmable potentiometer raspberry pi’

once u can control it manually, you can write code to do the same…

[CyruS1337]

Sorry that was a wrong picture. I have changed the picture now.

noctua.at/en/nf-a4x10-5v/faq

So when I connect the fan to PIN 1 and PIN 3, the fan runs.

That means for me that the fan works with 5V.

Do not I have to connect the yellow wire to a GPIO PIN to get the signal from there to turn the fan on and off?

[Peter]

https://hackernoon.com/how-to-control-a-fan-to-cool-the-cpu-of-your-raspberrypi-3313b6e7f92c
I use this.
It works fine, even wit a Google AIY Hat on top of the RPI.
I hope it works for you too.
Peter

[sdetweil]

@peter so, you made a transistor based relay… cool…

but that doesn’t help his speed control question…

[sdetweil]

@cyrus1337 the specs do not say how the yellow wire is used to control the fan.

[CyruS1337]

Maybe you misunderstand me. I just want to turn on the fan and turn it off when the CPU has more than 50 °. I have 3 wires on my fan as shown above.

[Peter]

That is exactly what I told you before.
Read the article and you will see how to connect the 3 wires.
And you can change the temperature of the fan to start.
My fan starts at 65 and runs for 30 seconds to cool the cpu.
Peter

[CyruS1337]

Thanks, I want to try it