Monitoring Temperatures on Octopi hardware

Hello everyone

I am new here. I have recently setup a Pi4 with OctoPi about a week ago now.

So far I am still learning how to use it so I basically have only used it for the camera.

Anyway. I went into my printer this morning and the fan on the raspberry pi sounded like it was going to take off. I find that a bit odd considering my printer wasn’t doing anything. Just idle.

My question is what does everyone do to monitor their temperatures and if possible, what do you use to change fan speed based on temperatures.

I realize that this is hardware related. I have asked in the raspberry pi forums as well but wanted to ask here for those running Octopi what they are doing.

My setup is a Pi4 with a geekworm heatsink and 30mm fan on it. It’s in a case that I printed that is mounted to the back of my Prusa MK4 frame. I have a ribbon cable coming out of that, connected to a pi cam.

I really don’t understand why the fan is spinning at a high rate of speed with everything at idle.

If I can provide any more details please let me know.


Can you provide a link to the geekworm product? How is the 30mm fan electrically connected to the RPi 4?

The simplest fan connection is a two wire connection to the GPIO header, one wire to a ground and the other wire to either 5v or 3.3v for full speed or two-thirds speed.

More exotic solutions can use some form of PWM to control the (3-wire) fan speed but this requires some additional configuration.

That is the product that I have. It is connected like it is in the picture. Red wire to PIN number 2 and black to PIN number 3. The pins are connected together.

This specific case that I printed was designed with that heatsink in mind. But that is my setup attached to the rear of the frame of my electronics box on my MK4.

That product uses a two wire fan and since the two pins are physically connected together, the only choice is to connect them to 5V power and Ground (see the diagram below). The pins you are using are pins 4 and 6.

There is only one speed for this fan and it could be noisy. If the noise has changed since you first installed it, check for something rubbing on the blades. These fans are also very cheap and not the highest quality. I've replaced multiple fans because the bushings don't last that long. It is possible to find better quality fans with ball bearings that will last longer. It is also possible to find 3-wire fans that can be connected and controlled via PWM.

Yesterday, the fan was significantly louder than it was during the first week or so after it was installed. I went in to clear the print bed this morning and the fan was basically silent. I heard it moving but it was not making the noise it was yesterday. That seems odd to me.

Here are some simple scripts I use for testing various cooling fan configurations. Some use sysbench to put a load on the system, install it with

sudo apt install sysbench.

cputest and cpucool take two arguments on the command line, m and n. m is the number of iterations and n is the time in seconds for each iteration.

cpufan and cputemp are variations of cpucool that default to one iteration.

cpuspeed watches the system clock frequency. (4.8 KB)

Another simple tool is s-tui. Google it for installation instructions.

I suspect that you have some mechanical issue with the fan. Check clearances around the fan blades.

I will try these out. Thanks!

Also, they pick up dust something awful! Bring some canned air and a brush.

Yea, I will keep that in mind but this setup has not been up and operational long enough for it to collect enough dust to be a concern.

It’s only been 10 days or so now.