After months of polishing, the water-cooled host specially built for Raspberry Pi by the Raspberry Pi enthusiast base is officially launched! ! !
After months of hard work by the team, our water cooling has finally been finalized, and the first final version has been made!
Actually it didn't take so long, mainly because I prefer water cooling, so this time I was responsible for the assembly and testing of the water cooling hardware, and then feedback to our hardware development team for them to modify. One is because I usually have relatively tight time and I don't have much time to make water cooling. The second is that our team has relatively high requirements for the things we make, and we have to change if there are minor problems. Because of these two factors, the water cooling takes longer, but the result is still very good. The things made are very good in terms of actual use effects and look and feel. When the first version of the final version is made I excitedly posted a message saying who would not like it, because he really made me love it!
Well, stop talking nonsense, look at things first!
After watching this demonstration video, many enthusiasts who have played host assembly may shout: "Water-cooled Happy Box!", that's right! ! ! Our hardware engineer was inspired by his own water-cooled computer mainframe and used a side-through design to create the world’s first "Raspberry Pi Water-cooled Happy Box."
After many adjustments, our shell was finally made of aluminum. The solution of the combination of alloy and acrylic. The acrylic on the front allows you to easily see the internal structure of the chassis and the equipment inside. It has a mechanical beauty. The remaining surfaces are made of aluminum alloy, which can guarantee The strength of this Raspberry Pi water-cooled happy box, and the aluminum alloy material will give users a delicate and thick feeling! There will not be the cheap and unstable feeling of plastic.
It can be seen that the overall shell is a combination of aluminum alloy and acrylic designed by ourselves. Inside there is a pcb control circuit of our own design. The core is an arduino nano, and of course the basic components of water cooling: water tank, water pump, cold exhaust, Fan, water pipe, of course, you can see that there is also a temperature sensor in the water tank, which is used to collect the temperature data of the coolant in the water tank. 
Next, let's talk about the function! Our Raspberry Pi water-cooled happy box is smart to adjust the speed of the cooling fan according to the load and temperature of your Raspberry Pi cpu to achieve the best heat dissipation effect, that is, when your cpu temperature or load is not high, the fan is It will turn slower, and it will turn faster when the temperature or load is high. All this is achieved by our own design program and pcb control circuit.
You can see that the first line of this small OLED screen displays the cpu load of the Raspberry Pi, the second line is the real-time temperature of the cpu, the third line is the temperature of the coolant in your water tank, and the fourth line is the cooling fan Speed, you can easily and quickly grasp the load and heat dissipation of your Raspberry Pi through this small screen!
Here I will talk about the advantages of using an external Arduino nano as a controller. First of all, although the Raspberry Pi can directly output the PWM signal, the main control unit of PWM is the clock in the processor, and the Raspberry Pi will change the clock under high load or overclocking/energy saving frequency, which will cause the PWM output to be inaccurate. Fans appear for a while faster and then slower, which greatly affects the experience. Secondly, the background control program is also constantly calling the processor's built-in clock when it constantly calls PWM, which will adversely affect other tasks in the system, and even seriously affect the stability of the entire system.
Finally, if you have arduino programming experience, users can customize the speed control algorithm according to their own ideas, instead of using our default algorithm, achieving a high degree of customization. At the same time, we may also release algorithm and driver updates in the future. At the same time, we reserve a set of multi-function IO ports, a digital port and an analog port. You can also add some favorite hardware devices to make your Raspberry Pi water-cooled happy box more cool (for example, you can add 5v Programmable A-RGB light strips, we will provide programs that support A-RGB in the future.) Note that users who do not have Arduino programming and necessary hardware knowledge are not recommended to try to rewrite the firmware or add hardware by themselves, which may cause hardware damage.
In terms of performance, there is no doubt that our Raspberry Pi water-cooled happy box has an excellent heat dissipation effect. Our design team has already "washed up" the Raspberry Pi last time. You can watch the warm-up video for details.
The following results are our test data under the room temperature of 26 degrees, for reference only, you can feel it.
You can find that the temperature performance of 4B is only slightly higher than that of 3B+, and the temperature difference between no-load and full-load is not much. This is not a data error. It is determined by the characteristics and advantages of water cooling. The specific heat capacity of water is large and the area of the Raspberry Pi cpu is relatively small. When flowing through the cold head, the water can absorb a lot of heat without increasing too much. The temperature and principle are exactly the same as the water cooling on high-end desktop computers. I will not explain the physical principle of water cooling here. After all, this is not the focus of our video. You can find it on Baidu.
So in fact, no matter how much heat the cpu generates, it is a trivial matter for our water cooling, and it is easily taken away, which provides an excellent condition for overclocking [don't overclock indiscriminately]. According to our experiments, our set of water cooling can easily suppress the heat generated by 5 quad-core fully loaded Raspberry Pi 4B at the same time.
As for how much the 4B quad-core load without water cooling can reach 100%, you can test it with your own Raspberry Pi! Fans who have used 3B+ and 4B at the same time should have felt the "enthusiasm" of Raspberry Pi 4B. The heat generation is not a little bit higher than that of 3B+. At this time, if you overclock it, it will overheat and shut down in minutes.
This result is the result of using poor-quality thermal paste on the cold head. Because the good-quality thermal paste has not arrived when I assemble this prototype, we will give a good-quality thermal pad along with it. .
