How to create a dev mini computer (based on Raspberry Pi)

As some of you know, I have a rather disabling disease. And when I can't walk down the stairs to my PC to code, I'm frustrated that I can't do what I want despite the pain.

However, I still found a reliable, silent and cheap idea : Make a mini computer based on an overclocked Raspberry Pi 4. I even used a 3D printed case to put a big fan inside. So I write this post to explain how I did it.

My needs

First of all, I needed a PC that consumes little power but that is able to run Youtube or Spotify for music, my web server tools (NginX, MariaDB, NodeJS, ...), my code editor (gEdit). Of course, it had to be easy to use and above all, all this stuff had to be fluid!

I also wanted to test the Raspberry Pi overclock. Basically, this principle allows this mini PC to run at a speed it is not supposed to reach. To do this, you have to cool it down. Others have done it before me and 3D printed cases are available for this kind of configuration.

Hardware

Here is the list of the material you will need to build this machine:

• A Raspberry Pi 4 8Go with power supply, SD card, mouse & keyboard
• Heatsinks, you can find them for 5€ on Amazon
• A 3D printer to print the case
• A 120mm fan (I recommend the Arctic F12 which is the best quality/price ratio)
• 2 dupont male-female wires

Build it !

Printing

I'm starting with 3D printing because it takes a lot of time and the rest can be done at the same time. I decided to use this model, created by Jesper Klang, which allows to put 120mm fan and send all the air directly on the Raspberry.

For the curious, I printed this with a Creality Ender 3 Pro with a 20% filling with ecoPLA. The bed is heated to 70°C and my nozzle is at 200°C

I also put a little grid over the fan to avoid getting hurt. You can find all kinds on Thingiverse

SD Card

While the printing is in progress, let's move on to the operating system, I tuse Manjaro Linux. I choose the XFCE Edition because it is the fastest available. It is a reliable and easy to learn distribution for beginners but it contains the necessary tools for power users too. However, you should know that any distribution will do (with some slight differences)

Building

Before mounting the case, don't forget to put your heatsinks. I preferred to use copper ones, but you should know that even small aluminium ones will do, thanks to the 120mm fan.

And speaking of the fan, I decided to supply it with 5V directly on the Raspberry (the ground on pin 6 and the +5V of the fan on pin 1 of the Raspberry GPIO). It is big enough to have an important air flow and it is very quiet since it runs at low speed.

All that is left to do is to put the Raspberry inside the case, to clip it on. The fan is fixed with standard screws (supplied with the Arctic F12) and the grill is placed on top.

All that's left is to slide the SD card into the Raspberry and the construction is FINISHED :)

Software improvements

Overclock

Increasing the operating frequency of a Raspberry is clearly not difficult since it is a matter of modifying a file. However, before doing so, I advise you to power your machine with a good quality 5V / 3A transformer.

You have to edit the file /boot/config.txt . Concerning the overclock here are the lines to modify :

over_voltage=6
arm_freq=2000

I also decided to activate the hardware graphics rendering even if it is still in experimental status. It does not cause any problems for me and allows a better fluidity:

gpu_mem=256
dtoverlay=vc4-fkms-v3d
max_framebuffers=2
disable_splash=1
hdmi_enable_4kp60=1

Just reboot and you'll have a compact, quiet computer that's fast enough to do most developer tasks.

Tweaks

Depending on the distribution, you can always improve performance. For example, check if your distribution allows you to remove compositing options or disable shadows under windows. It's not as pretty, but it's faster.

You should also use light tools. In my example, since I'm doing web development, I chose NginX as my web server because it's much less greedy than Apache2.

Prefer to remove the wallpaper too, it avoids having to take on graphic memory. Also think of changing the password, for security reasons.

If you have feedbacks or questions, don't hesitate to post them in comments ;)

Posted with STEMGeeks