If you are a Raspberry Pi user, you will quickly learn that the range of possible displays on the market is staggering. It can be hard to choose which one is right for your needs and budget with the myriad options available. In order to make things easier, we have compiled a list of things you should consider when selecting a display for your Raspberry Pi single-board computer.
1. Resolution of the Display
Screen resolution is the number of individual pixels a screen can show horizontally and vertically. For example, a display with a resolution of 3840×2160 (4K) has 3,840 horizontal pixels per row and 2,160 vertical pixels per column. Together with factors such as PPI (pixels per inch) and screen size, the resolution determines how crisp and sharp images will look. Raspberry Pi OS doesn’t list an official minimum resolution, but you should aim for 480×320 or higher.
2. Screen Size of the Display
Screen size refers to the actual physical dimensions of the screen and is measured diagonally across the screen. Thanks to the Raspberry Pi’s HDMI output, you can connect it to any size HDMI monitor or TV.
Alternatively, you may want something more portable. The official Raspberry Pi Touchscreen Display is a 7-inch, multitouch screen with a 800×480 resolution, but you will find displays as small as 3.5 inches (diagonal size). It all hinges on your preference and intended application.
3. Refresh Rate of the Display
The refresh rate of a display refers to how quickly it can draw a new image on the screen. The refresh rate also affects whether you experience screen tearing or frame drops when using the display. Note that the refresh rate of a monitor can only be as fast as the GPU of the computer allows. The Raspberry Pi’s 4K video output is set to 30Hz by default, but it can be adjusted up to 60Hz on a Pi 4 or 400.
For a Raspberry Pi 4, look for a display with a refresh rate of at least 60Hz if you are planning to use it in a desktop environment or for emulation.
4. The Interface Used by the Display
There are three main ways in which you can connect a display to your Raspberry Pi: through the HDMI port, DSI port, or the GPIO expansion header (I2C or SPI).
The Raspberry Pi 4 and 400 have two micro-HDMI ports, while most other models come with full-size HDMI ports. You can also connect a display HAT to your Raspberry Pi’s GPIO header and use it mounted on your Pi.
5. Touchscreen Functionality
This is another helpful feature to look out for when picking a display. Having a touchscreen display means that you can use your Raspberry Pi without a keyboard or mouse attached and can be quite handy when working on the go. Note that you’ll need to install an on-screen keyboard such as Onboard, however.
Since HDMI cannot transmit touchscreen signals, touchscreen monitors for the Raspberry Pi usually route touch input data as well as power through the USB-C connector. Alternatively, you can use the MIPI DSI port or use the GPIO header’s serial interfaces. You should also be aware of the differences between capacitive and resistive touchscreens when choosing a touch display.