What fun would a computer be without a screen to see what you’re doing? Well if you own a Raspberry Pi and are curious about the different ways you can connect an external display or monitor up to it, then look no further. Today we’ll be looking at how to hook up a screen for your Pi in four different ways; HDMI, composite, GPIO, and LCD DSI.
**Note that when we use the words ‘display’, ‘monitor’, and ‘screen’, they are all referring to the same thing**
To follow along with this tutorial you will, of course, need a Raspberry Pi and everything required to get up and running with it. For more info on this, take a look at our 'Hello World with Raspberry Pi' tutorial.
In addition to this, you’ll need a display. You can use any screen that has an HDMI port on it such as a TV or computer monitor (High Definition), a composite RCA port (Standard Definition), or a special LCD DSI or GPIO header display. If you don’t yet have a display for your Pi, check out the various methods below to decide what is going to be best for you.
Connecting to an HDMI Display
This is the easiest and most reliable method of connecting an external screen to your Raspberry Pi. HDMI is a video standard created in the early 2000’s which has supports 1080p High Definition (HD) and 2 channel (stereo) audio. It’s a plug and play standard, which means there’s no special drivers to install and no fiddling to get it to work. You simply power down your Pi, plug either end of an HDMI cable into the HDMI port on your Pi, and the other into the HDMI port on your display.
HDMI supports various screen sizes from a small computer monitor to huge 80” TV’s.
Connecting to a Composite Video Display
Whilst every TV and consumer display is now supported by HDMI, some older displays such as bulky CRT monitors aren’t, but instead may have the older RCA Red, White, and Yellow plugs. Composite video isn’t recommended for most users because you have to alter the config.txt file to tell your Pi to use composite video, and it’s only Standard Definition (SD) which means your picture quality won’t be very good.
However, the Pi does come with support for composite video via the 4-pole TTRS 3.5mm jack which looks like a regular headphone jack but supports video on the extra signal conductor. In order to use composite video, though, as we mentioned, you will need to change 3 lines in the config.txt file. If you already have your Pi connected up to a display, then follow these steps:
- Connect power to the board and hold SHIFT on your keyboard during startup to launch into the NOOBS manager
- In the top bar, select ‘Edit config’
- Find the line ‘#sdtv_mode=0’ and change it to ‘sdtv_mode=2’ (remember to remove the ‘#’ symbol)
- Now, anywhere in the text file, add the line ‘hdmi_ignore_hotplug=1’
- Find the line ‘hdmi_force_hotplug=1’ and make sure there is a ‘#’ symbol before it to comment it out
**Note that if you want to use your Pi with an HDMI display, you will need to reverse the last two steps**
To connect your Pi up like this you will need a 3.5mm 4-pole to RCA (Red, White, Yellow) cable. Plug the 3.5mm jack into the socket on your Pi, and connect the RCA connectors as follows:
- Yellow: Video
- White: Audio Left
- Red: Audio Right
The fourth pole on the 3.5mm connector is for Ground which is connected to every RCA plug. Some 4-pole to RCA cables may have a different pinout than the Raspberry Pi so you may need to experiment with the different colours to find the correct signals.
Connecting to an LCD DSI Display
The Raspberry Pi has a small connector for a 15-pin ribbon cable which supports the Display Serial Interface (DSI) standard which allows for high-speed communication between LCD screens. At the moment, the best display to use with this connector is the official Raspberry Pi 7” Touchscreen which supports 10-point capacitive touch.
Connecting up the display is fairly straight forward, it’s designed so that the Pi can be mounted on the back of it with all of the cables tucked away nice and neatly. To connect up your display, follows these steps:
- Attach Raspberry Pi board to the back of the display using the screws and standoffs provided
- Carefully connect the ribbon cable to both the Pi board and display control board noting the orientation of the ribbon cable pins
Be sure to carefully release the tabs on either side of the socket which allows the cable to slide in all the way, then secure it by pressing down on the tabs until they lock in. You shouldn’t have to force the cable.
To power the display, you can do ONE of the following:
- Connect the included jumper wires from the 5V and Ground on the Pi GPIO pins to the control board
- Connect the power supply up to the control board, then connect a second, small microUSB cable from the USB port on the control board to the microUSB on the Pi for power
Your Pi may no display anything on the screen yet, in which case you will need to use an existing HDMI display to update your Pi and reboot by entering the following:
As usual, before starting anything, you'll need to make sure that you're running the latest build of Raspbian. To do this, open a new Terminal window and type:
sudo apt-get update
Follow the prompts, and then type:
sudo apt-get upgrade
Your Raspberry Pi board should now be running the latest version of Raspbian, now enter the following to reboot:
For more info on the Raspberry Pi 7" Touchscreen, check out the Raspberry Pi Foundation post about it and the development
Connecting to a GPIO Header Display
And the fourth method for connecting a display to your Raspberry Pi is using the GPIO headers. This isn’t the recommended method for a primary display as it takes up all of the GPIO headers, and uses a slower Display Parallel Interface (DPI). It can still be a good option as a small display for projects, however, depending on the display, some extra drivers may be required to use the display. A good example of this is the Display-O-tron HAT from Pimoroni which provides an RGB backlit LCD character display, along with capacitive buttons, making it the perfect choice for a menu driven UI.
For information on using that HAT, and the general process for installing drivers for your device of choice, check out our 'Raspberry Pi HATs' tutorial. Screens designed to work with the GPIO headers should have installation instructions for their drivers, however, you need to be careful that you buy one that is compatible with your model Pi. For example, a HAT designed to work with the older, 26-pin Raspberry Pi may not work with the newer B+ models which have a 40-pin header, and vice versa.