{"id":240981,"date":"2023-11-27T11:41:18","date_gmt":"2023-11-27T10:41:18","guid":{"rendered":"https:\/\/emariete.com\/?p=240981"},"modified":"2023-12-03T21:47:53","modified_gmt":"2023-12-03T20:47:53","slug":"fan-speed-variable-raspberry-pi","status":"publish","type":"post","link":"https:\/\/emariete.com\/en\/ventilador-velocidad-variable-raspberry-pi\/","title":{"rendered":"Tutorial: Temperature-controlled variable speed fan for Raspberry Pi"},"content":{"rendered":"

Do you want to, like me, reduce Raspberry Pi fan noise<\/strong> (or even eliminate it)? If so, here is the ultimate solution to our noise problems: the variable speed fan for Raspberry Pi. An easy and cheap solution (a couple of euros).<\/p>\n\n\n\n

This tutorial is accompanied by a video<\/strong>I'll leave it below, so that you can follow it very easily.<\/p>\n\n\n\n

Following this tutorial, you will be able to build, with very few components, a small controller for the Raspberry Pi to regulate the speed of its fan depending on its temperature and we will complete it with a small Python program to do the monitoring and control work.<\/p>\n\n\n

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Whenever I write a blog post, my top priority is always to that provides value for the reader<\/strong>that actually provides knowledge. Not write empty articles that just skim over a topic with information that is already all over the internet.<\/p>\n\n\n\n

Why have I written this tutorial on how to set up a temperature-controlled variable speed Raspberry fan, when there are already many on the internet?<\/p>\n\n\n\n

Because the articles I found seemed too biased, or didn't seem to explain the basics well, in a way that I didn't think they could. understandable<\/em>.<\/p>\n\n\n\n

In addition, I have found that most tutorials for implementing temperature-based PWM speed control on the Raspberry Pi THEY DON'T DO IT WELL<\/span><\/strong> (I will explain why later).<\/p>\n\n\n\n

This article (and the other articles it links to, which I have written in support of this tutorial), attempt to cover the topic in depth but understandable<\/em>, trying to that anyone can easily understand it just by reading the blog and with no prior preparation.<\/strong>.
I hope you enjoy it!<\/p>\n\n<\/div>\n\n\n

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It seems unbelievable how long it took, both hardware and software, until everything worked perfectly. <\/p>\n\n\n\n

The fact that it has taken longer than expected has not discouraged me at all, quite the contrary. This means that the subject is not so simple and that this article will have a lot of value.<\/strong><\/p>\n\n\n\n

The truth is that I have learned a lot along the way. I didn't expect that such an apparently simple subject would give me so many headaches.<\/p>\n<\/div><\/div>\n\n\n\n

<\/p>\n\n\n\n

I have several Raspberry Pi running at home for different tasks. They are small devices, with low power consumption and very stable in their operation (they can be running continuously for months without needing a reboot).<\/p>\n\n\n\n

I have used the original Raspberry Pi (the v1), the Raspberry Pi 2, the Raspberry Pi 3 and its \"in-between\" versions (with the \"B\" or \"+\" added) and temperature has never been an issue. They have all worked great for years with no heat problems.<\/p>\n\n\n\n

The last one I added, a Raspberry Pi 4, has much more power and performance than the previous ones and that means that it has some cooling requirements far above those of their predecessors<\/strong>Can a Raspberry Pi 4 be used without a fan? Yes, but it is not advisable to run a Raspberry Pi 4 without a fan<\/strong> to refrigerate it.<\/p>\n\n\n\n

It is assumed that if we put a Raspberry Pi 4 it is because we need its power in some moments (if not, why use a Raspberry Pi 4?, better to put one of the previous models, which are cheaper and consume less) and in this case to provide it with a cooling fan is almost indispensable<\/strong>.<\/p>\n\n\n\n

The disadvantage of adding a fan to the Raspberry Pi 4 is that ceases to be a silent 100% device<\/strong> to become a minor nuisance (especially in a quiet bedroom or office).<\/p>\n\n\n\n

How loud is a Raspberry Pi 4?<\/h2>\n\n\n\n

The Raspberry Pi 4 itself does not make noise<\/strong>has no moving parts, what makes noise is its fan<\/strong>\u2026<\/p>\n\n\n\n

The noise level of a 5V fan for a Raspberry Pi 4 can vary depending on the model and make of the fan, as well as its design and build quality. However, in general, small 5V fans tend to be quite quiet, especially if powered at 3.3V (yes, 5V fans powered at 3.3V so they spin slower and make less noise).<\/p>\n\n\n\n

The noise level of a fan is generally measured in decibels (dB), and small 5V fans designed for Raspberry Pi often have a noise level of around 20 to 30 dB. This is relatively quiet and should not be annoying in most situations.<\/p>\n\n\n\n

It is important to note that there are some factors that can influence the noise level, such as the speed at which the fan operates and the quality of the fan's bearing. If you need particularly quiet operation, you can opt for fans with high quality bearings, such as fluid bearings or ball bearings, which tend to generate less noise than simpler bearings.<\/p>\n\n\n\n

In any case, if noise is a concern for you, you can look for fans designed specifically for low-noise applications or those with speed control options to adjust fan speed as needed, which can help you maintain a balance between temperature and noise.<\/p>\n\n\n\n

Taking all of the above into account, we can say that the fan noise of a Raspberry Pi 4, once we have chosen the fan (better or worse, higher or lower quality) and connected it, will always spin at the same speed, cool in the same way and make the same noise.<\/strong>.<\/p>\n\n\n\n

If we want to reduce the noise, taking advantage of the fan always running at maximum (in fact, we don't even need the fan to be always running) the solution is to have a variable speed fan for Raspberry Pi.<\/p>\n\n\n\n

Why should I put a fan on a Raspberry Pi 4?<\/h2>\n\n\n\n

It is good to put a fan on a Raspberry Pi 4 or other similar electronic devices for several reasons:<\/p>\n\n\n\n

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  1. Refrigeration:<\/strong> The Raspberry Pi 4 can generate heat, especially when running CPU or GPU intensive applications. A fan helps dissipate that heat more efficiently, which prevents the device's temperature from rising too high. Operating at lower temperatures can help prevent overheating, which can negatively affect the Raspberry Pi's performance and lifespan.<\/li>\n\n\n\n
  2. Increased performance and stability:<\/strong> Keeping the temperature of the CPU and other components at a lower temperature can allow the Raspberry Pi to run more steadily and without slowdowns caused by overheating.<\/li>\n\n\n\n
  3. Damage prevention:<\/strong> Excessive heat can damage electronic components over time. A fan can extend the life of the Raspberry Pi and prevent long-term damage.<\/li>\n\n\n\n
  4. Consistent performance under intensive workloads:<\/strong> If you plan to use your Raspberry Pi for intensive tasks, such as game emulation, machine learning or video transcoding, a fan can be essential to maintain consistent performance and avoid thermal throttling.<\/li>\n\n\n\n
  5. Reduced fan speed and noise:<\/strong> You don't need the fan to be at full speed all the time. You can set the fan to run only when the temperature reaches a certain threshold, which helps reduce noise and power consumption.<\/li>\n<\/ol>\n\n\n\n

    All of the above confirms what we suspected, putting a fan on a Raspberry Pi 4 is a good idea if you plan to use it for tasks that generate heat or in environments where the ambient temperature is high. It will help keep the Raspberry Pi running efficiently and prolong its lifespan by keeping temperatures under control.<\/p>\n\n\n\n

    And since we're putting a fan, we'd better put a variable speed fan for Raspberry Pi.<\/p>\n\n\n\n

    What is the quietest Raspberry Pi 4 fan?<\/h2>\n\n\n\n
    \"\"<\/figure>
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    I can tell you, without fear of contradiction, that the quietest fan is the fan that is switched off.<\/strong>.<\/p>\n\n\n\n

    We can put better quality fans, lower voltage, graphene or Kryptonite bearings, but all of them, without exception, make noise.<\/p>\n\n\n\n

    If we want a fan to be silent, the best way is to turn it off <\/strong>when it is not necessary and put it to the minimum speed<\/strong> to keep the temperature of the Raspberry Pi 4 under control (it is not necessary that it is always \"always on\").as cold as possible<\/em>\").<\/p>\n<\/div><\/div>\n\n\n\n

    However, if I have something to tell you: As a general rule, Raspberry 4 fans are very small (usually 40mm) and this means that they have to rotate very fast in order to provide a significant amount of air. <\/p>\n\n\n\n

    To move the same amount of air, a smaller fan (such as a 40 mm fan) must spin approximately 9 times faster than a larger fan (such as a 120 mm fan).<\/p>\n\n\n\n

    The speed ratio is calculated as follows:<\/p>\n\n\n

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    \"\"<\/figure>\n<\/div>\n\n\n

    Where:<\/p>\n\n\n\n