Re-use your, old laptop screen to build a cool desktop with Raspberry pi.
Preconditions : - The screen should not be damaged, just remove the screen from any unusable or dead laptop, disconnect the screen from the laptop motherboard by disconnecting the LVDS cable and the inverter board. Now connect the right LCD controller and you are ready with your super pi desktop !!
Step 1: Components List
1. An old laptop screen (screen should not be damaged)
2. LCD Controller board kit for laptop screen
3. Power supply adapter (according to LCD controller kit, usually 12 V, 4 amps)
4. Raspberry Pi (Other MCU can be used subject to availability of ports) along with Power supply cable
5. HDMI to VGA Cable :- Iworld make , works perferct with pi.
6. Wireles keyboard (Wired can also be used).
7. Wifi Dongle if Using Pi 2/B+ (Pi 3 has inbuilt wifi)
8. A suitable stand for holding the screen in place.
Step 2: Understanding the Basics of LCD
As outlined in step -II, LCD controller kit contains the controller board the inverter and the LVDS cable, so before we begin our installation of components, lets look into the working of LCD
An LCD (liquid crystal display) panel uses multiple components to create the image you see on the screen. The liquid crystals are arranged in a layer near the front of the screen. As the crystals rapidly change color, they create an image. This image would not be viewable, however, without a backlight. The backlight is located behind the crystal layer and shines through the crystals to provide enough light for the users to see the image.
The backlight of an LCD screen, requires AC power rather than the DC power provided by the laptop’s power supply. This is where the inverter comes in. The inverter converts the DC (direct current) that comes from the laptop’s power supply to the AC (alternating current) that is needed for the backlight of the LCD screen.
LVDS stands for Low-voltage differential signaling and is basically pair of twisted copper cables used for high speed communication, here we are using this cable to communicate between controller board and screen
Step 3: The LCD Controller Kit Selection Guidelines
I have ordered one from ebay, you can refer to following link : -LCD Controller , the kit includes the LVDS cable, inverter and the control buttons too.)
You can also refer to other sources for LCD controller board selection like:-
Step 4: The LCD Controller & the Inverter Board
As in the above image normally all LCD controllers are connected as:-
- Connect Inverter Board to LCD controllers (connection cables are supplied along with) (Caution :- do not remove the top plastic covering on the inverter board)
- Connect Keypad Board to LCD Controller.
Now LCD controller board is ready and we need to just connect it to Laptop screen, via the LVDS cable at top, while the bottom end should go to inverter board for power supply.
Step 5: The Screen Holder
There are various types of stand available online , moreover one can design one's own to give that more perfect look for the desktop.
To save time and things look simple, i have used a simple foldable stand. The same works fine for holding my 15.6 inch laptop screen.
Step 6: Connecting the LCD Controller to Screen
- The first step is to remove old LVDS and old inverter along with wires from the laptop screen
- Than connect the LVDS Cable from the controller to the laptop screen (the connection is easy and is push fit type normally)
- Than connect the inverter cable from the screen to the inverter board (normally there are two wires red and white)
- To minimize the backlight reflection from behind the screen, paste black chart paper as shown on the screen.
- To mount the LCD Controller on back, i have used thermocoal with suitable cutting.(Any other suitable method can be used to give more robust look)
Step 7: The Final Desktop
Once the LCD controller board is assembled and connected to screen, its time to connect the Raspberry pi
- Normally the LCD controller board output is VGA (some controller also have HDMI output). So to interface raspberry pi with the controller board , we need VGA to HDMI cable.
- The VGA to HDMI cable is easily available online and works straight with the pi i.e no extra coding is required.(Caution :- some VGA to HDMI may not work with pi, i have used the one manufactured by "iworld")
- We can used wired or wireless keyboard. ( I prefer wireless keybaord from logitech K400 Plus, its just plug and play feature, which makes it more convenient to use.)
- Connect power supply to LCD controller (In my case it is 12 V, 5 Amps power adapter)
- Connect power supply to Raspberry pi
Raspberry pi is now ready to be used as full desktop, just load latest Raspbian OS and have your own configurable desktop.