Low-Tech laptop with a Raspberry PI
Hi everyone ! In this article I’ll showcase how to “build” a low-tech laptop with a Raspberry PI 4 and scrap pieces of an old non low-tech laptop. This article will evolve in the following weeks / months as I improve my prototype.
The idea for the first few steps came from this Instructables article.
These are the first basic steps you’ll need to follow to make this DIY laptop run. There is a lot of room for improvement, but it worked for me, so it should work for you.
Check out the end of the article for upcoming improvements.
Step 1 — Get the stuff
We need a few things to get started :
- 1x Raspberry PI 4
- 1x HDMI cable (mini to regular)
- 1x 5V USB-C power supply (for the Raspi)
- 1x SD card (recommended 8GB minimum capacity)
- 1x old laptop LCD monitor
- 1x LCD screen driver board
- 1x Power supply for the driver board (mine is 12V 3A)
- 1x USB keyboard
- Optional : 1x USB mouse
Raspberry PI
You can get it from $35 for the 2GB RAM model to $90 for the 8GB RAM. It all depends on what you want to do with it. I’m a developer and I want to use it for work, so I got the 8GB.
I also recommend you buy a protective case for it. Mine also has a little ventilator, which is a bit noisy but very handy as the Raspi can heat up quickly.
Quick tip : when you mount the ventilator, make sure it blows air OUT of the case.
SD Card
For the SD card, you can go low capacity, but I personally recommend at least 8GB. If your goal is to use the Raspi for desktop applications, find a higher capacity and ideally Class 10 SD card (those are faster).
Laptop LCD monitor
This is where the fun begins. Get an (ideally out of service) old laptop, carefully disassemble it and get the screen. You can keep other parts aside for later use, such as hard drive, keyboard, webcam, CPU, GPU, motherboard… It can always be re-used !
Do not touch the “DO NOT TOUCH” part on the back of the screen !
The screen has two inputs that are interesting for us :
- the actual signal port (hopefully LVDS)
- the power supply cable
You may find other cables. If you don’t know what they are or what they are used for, don’t remove them.
Another important information that you will find on the back of the screen is the serial number. Write it down, you’ll need it to find the compatible driver board.
Please make sure that the screen is in good condition before doing anything with it !
LCD screen driver board
Your screen needs a compatible driver board to make this work.
Basically, it will power your screen with AC, send visual signal from HDMI, VGA and DVI through the LVDS port, and provide screen settings (lighting, contrast…).
Use the screen serial number to find your board. I found mine on AliExpress : https://www.aliexpress.com/item/4000228322290.html?spm=a2g0s.9042311.0.0.67634c4dyxV7Yn
If you can’t find it on AliExpress, try Ebay. If you still don’t find it, email a seller to know if they have it in store.
In any case, I strongly recommend you email the seller to make sure it’s the proper model !
You will also need a power supply for the driver board. Check out the board specs to fetch the correct one. Mine needs 12V 3A DC input.
I happened to have just the right one at home, but if you don’t you can find it in many hardware stores or online.
Others
Find an HDMI mini to regular, a 5V USB-C power supply (for Raspi 4 only, earlier versions have mini USB-B), and an external keyboard.
Step 2 — Install your favorite OS
There are several interesting operating systems you can use on the Raspberry PI.
The first one you’ll come across is Raspbian, the official Linux based distro. It’s the best choice for newby users looking for a smooth experience. The many advantages are described here.
There are a few fun ones such as RetroPie, fully dedicated to retro-gaming with a lot of emulators, or specific ones such as Kali Linux, for more hacky purposes.
You can go with whatever OS you like, they all have pros and cons. The great thing about the Raspi is that you don’t really have to choose. You can always get more SD cards, burn different OS on each one of them, and try them all !
You’ll see in the following steps that I chose Raspbian, but don’t worry if you go for Ubuntu, Kali or any other Debian based OS, the installation steps will be pretty much identical.
Download the OS image
First, you’ll need to download the OS image, usually from the official OS website. For Raspbian, go there : https://www.raspberrypi.org/downloads/raspberry-pi-os/
Burn it to the ground
Depending on your computer’s OS and tech skills, you have several options for flashing an image on a SD card. Again, for simplicity’s sake, I personnally use Etcher. It’s usable on Linux, Windows and MacOS, very easy, very fast, and you can’t possibly f*** things up.
Install Etcher, insert your SD card in your computer, launch Etcher and follow the steps.
- Select the OS image
- Select the SD card
- BURN IT !
It usually takes around 2–3 minutes to flash. Get a cold beer and come back when it’s done !
Step 3 — Plug it all together
The cool and satisfying part. If you do everything right, by the end of this step you should have a working PC !
Once you have all the parts, just gather them and plug them all together.
Plug the screen to the driver board
First, plug the driver board LVDS pin to the screen port. Careful, it’s fragile.
Then plug the screen power supply to the driver board inverter.
Plug the power supply to the board, and light it up ! You should see something like “No Signal”, and then nothing. It’s normal, most boards go to sleep when no signal is received.
Prepare the RasPI and plug it to the board
Insert the SD into the PI, fetch the power supply and plug the Raspi HDMI to the HDMI port of the driver board.
Plug the power supply, et voilà ! You should see something appearing on the screen. It may reboot a few times to install everything.
Step 4 — Let your OS install itself
The first time you plug the Raspberry PI, the OS will install a few packages. Basically, just wait. After a while, it should be up and running !
Raspbian will guide you through a quick wizard for basic configurations and additional packages. Just follow the steps, and you’ll be good to go.
That’s it !
Costs
Here’s a quick summary of what it cost me to build this setup.
Must buy :
- 1x Raspberry PI 4 -> $35 to $90 depending on the version / RAM
- 1x Raspi case -> $10 to $30 depending on the model
- 1x LCD screen driver board -> $20 to $30 depending on the model
Can be found for free / recycled :
- 1x 12V power supply -> $20
- 1x SD card -> from $10 to $40
- 1x 5V power supply -> $15
- 1x External keyboard -> $25
So basically, for $65 you can have a pretty decent mini computer. If you go up to 130 (same setup but with more RAM), you have a very decent mini computer.
If you have none of this equipment, it will cost you around $200 for a good setup.
I encourage you to go full low-tech and try to find all the parts from recycled old gear. There are tons of unused / out of service electronic equipment out there, and if you search enough you’ll find what you need.
Upcoming improvements
So, yeah, right now it works, but it’s still pretty ugly and not very handy. There’s a LOT of room for improvements.
- First things first, the case. I found a little plastic case that fits the dimensions of my hardware. First step would be to glue it all inside and build a protective panel to hide all the cables / boards.
- I’d also like to work on the keyboard. I don’t really like having a brand new keyboard for a low-tech PC, so I’m checking out how to re-use the old one from the laptop.
- For now I have two power supplies, one for the PI and one for the driver board. This is not at all convenient. I’m building a little converter to have one main power supply and split to 5V for the PI & 12V for the board.
- Next, the battery ! All respectable laptops have one, mine does not. I need to make it happen. I already scrapped battery parts from another old laptop (3.7V 21700 batteries, same as vaping devices). For this, I’m following this awesome tutorial from the just as awesome non profit Low-Tech Lab.
Bonus — Le Wagon setup
For those of you coming from Le Wagon, here are a few tips for the initial setup.
Basically, since Raspbian is Debian based, just go through the regular setup and you’ll be fine.
Text editor
The only difference is in the text editor. Sublime Text doesn’t have support for ARM architecture (yet). So you won’t be able to use it for your dev purposes.
There is a community build of VS Code for ARM. I personally find it pretty slow, so I use Vim instead. It’s a very light and powerful text editor, 100% in the terminal. I find it really handy and very fast, especially on a Raspberry PI. I highly recommend you go for that. It’ll take a few days / weeks for you to familiarize with the tool, but in the end you’ll be much faster and efficient, I guarantee it.
Here are a few plugins I use with Vim to improve UX :
- Ctrl-p file finder : https://github.com/ctrlpvim/ctrlp.vim
- NerdTree explorer : https://github.com/preservim/nerdtree
- Vim Airline status bar : https://github.com/vim-airline/vim-airline
- Ack Vim : https://github.com/mileszs/ack.vim
- OneHalf theme : https://github.com/sonph/onehalf
- Autocomplete : https://github.com/Shougo/neocomplete.vim
Check out this article for cool plugins to use with Ruby & Rails.
bcrypt
You may also encounter an issue with bcrypt when installing Devise. The 3.1.13 version is x86 by default, so my workaround was to downgrade it to 3.1.12.
Postgresql
Depending on your OS, you may find difficulties starting Postgresql. I know I struggled a bit for Arch based OS (Manjaro), but nothing too complicated.
Thank you for you time ! Please comment this article and suggest improvements, or share your prototypes. I’ll soon upload this to the Low-Tech Lab wiki.
