Choosing the right display is not only about size or price. The best display depends on what the project needs to show, how often the information changes, how much power is available, how many pins are free, and which software libraries are available.
This article explains the most important practical selection criteria for LCD, OLED, ePaper, 7-segment, LED dot-matrix and WS2812B displays in Arduino, ESP32, Raspberry Pi Pico and similar embedded projects.
Start With the Information You Want to Show
The first question is not which display looks best. The first question is what the display actually needs to show.
- Only numbers
- Short text messages
- Menu settings
- Sensor values
- Icons or symbols
- Graphs or waveforms
- Images or color graphics
- Animations or visual effects
A voltmeter does not need a full-color TFT display. A graphical menu cannot be built properly with a basic 7-segment display. Matching the display to the information is the most important step.
Simple Text: Character LCD
Character LCDs are a good choice when a project needs to show text in a simple and reliable way.
Common formats include 16x2 and 20x4 modules.
- Good for menus
- Good for status messages
- Good for sensor values with labels
- Easy to use with Arduino libraries
- Available with parallel or I2C connection
A character LCD is not suitable for detailed graphics, but it is still one of the most practical displays for simple embedded devices.
Small Status Screen: OLED
Small OLED displays are very popular when a compact display with high contrast is needed.
Typical modules use SSD1306, SSD1309 or SH1106 controllers.
- Very readable in dark environments
- No backlight required
- Good for compact projects
- Works well for small icons and simple graphics
- Available with I2C or SPI interface
OLED is often a better choice than a character LCD when the project needs a modern look or a small graphical screen.
Color Graphics: TFT LCD
TFT LCD displays are the usual choice when color graphics are required.
Small TFT modules often use controllers such as ST7735, ST7789 or GC9A01. Larger parallel TFT displays may use controllers such as SPFD5408.
- Good for color menus
- Good for gauges and dashboards
- Good for icons and simple images
- Better refresh speed than most ePaper displays
- Usually needs more code and memory than text displays
A TFT display is useful when visual appearance matters, but it usually needs more microcontroller resources than a simple LCD or OLED.
Low-Power Static Information: ePaper
ePaper displays are useful when the displayed information changes rarely and must stay visible with very little power.
Unlike most other displays, ePaper can keep an image visible without continuous power.
- Excellent for battery-powered devices
- Good readability in bright light
- Useful for labels and information panels
- Very low power when the image is static
- Slow refresh compared with LCD or OLED
ePaper is not the right choice for fast-changing values, animations or smooth user interfaces.
Numbers From a Distance: 7-Segment LED
7-segment displays are best when the project mainly needs to show numbers.
They are commonly used in clocks, counters, voltmeters, thermometers and timers.
- Very easy to read
- Bright and visible from a distance
- Good for numeric values
- Available as single-digit or multi-digit modules
- Usually controlled by a driver chip
A 7-segment display is not flexible, but for numbers it is often better than a tiny graphic display.
Scrolling Text and Symbols: LED Dot Matrix
LED dot-matrix displays are useful when text, icons or simple graphics must be bright and visible.
Common driver chips include MAX7219, TM1640 and IS31FL3731.
- Good for scrolling messages
- Good for simple icons
- Bright and visible
- More flexible than 7-segment displays
- Lower resolution than LCD or OLED graphic displays
LED dot-matrix displays are a good choice for signs, indicators and simple animated displays.
Color Effects: WS2812B LEDs
WS2812B LEDs are useful when color effects are more important than readable text.
They are available as strips and matrices such as 1x8, 4x4 and 8x8.
- Each LED can have its own RGB color
- Only one data signal is required
- Good for indicators and effects
- Useful for simple pixel art
- Can require a strong power supply
WS2812B LEDs are excellent for visual effects, but they are not a replacement for a high-resolution text or graphics display.
Resolution and Readability
Resolution matters only if the project actually needs detail.
A 128x64 OLED can show small icons and text, but it cannot show the same amount of information as a larger TFT. A 7-segment display has very low resolution, but it may still be easier to read from across the room.
- For short text: character LCD or OLED
- For small graphics: OLED or graphic LCD
- For color graphics: TFT LCD
- For numbers at a distance: 7-segment LED
- For scrolling signs: LED matrix
Interface: I2C, SPI or Parallel
The display interface affects wiring, speed and pin usage.
- I2C uses only two signal lines and is very convenient
- SPI is usually faster and better for graphic displays
- Parallel uses more pins but can move data quickly
- WS2812B LEDs use a timing-sensitive single data line
For small displays, I2C is often the easiest option. For fast graphic updates, SPI is usually better. Parallel displays are useful only when the microcontroller has enough free pins and the software supports the display properly.
Power Consumption
Display power consumption can vary a lot.
A small OLED may use little power when only a few pixels are lit. A TFT LCD may use much more current because of its backlight. LED matrices and WS2812B displays can draw high current when many LEDs are on at high brightness.
- LCD power is often dominated by the backlight
- OLED power depends on how many pixels are lit
- ePaper uses power mainly during refresh
- LED displays depend heavily on brightness
- WS2812B displays can draw high current at full white
For battery-powered projects, display choice can be just as important as microcontroller choice.
Software Library Support
Before choosing a display, check whether a reliable library exists for the controller chip.
The display size alone is not enough. A 1.3 inch OLED may use SSD1306, SSD1309 or SH1106, and the correct library or configuration matters.
- Check the controller chip
- Check the interface type
- Check the resolution
- Check the I2C address if using I2C
- Check whether the library supports your microcontroller
Good library support can save many hours of troubleshooting.
Typical Display Selection Guide
| Project Need | Recommended Display | Why | Watch Out For |
|---|---|---|---|
| Simple menu | Character LCD or OLED | Easy text display | LCD size limits, OLED small screen size |
| Sensor readout | OLED, character LCD or 7-segment display | Good readability for values | Choose based on viewing distance |
| Color dashboard | TFT LCD | Supports color graphics and icons | More code, more memory, backlight current |
| Battery-powered label | ePaper | Keeps image without power | Slow refresh, not for fast updates |
| Clock or counter | 7-segment LED | Large, bright numbers | Limited characters |
| Scrolling sign | LED dot matrix | Bright and readable for moving text | Low resolution, current consumption |
| RGB effects | WS2812B strip or matrix | Individually controlled full-color LEDs | Power supply and timing requirements |
| Round visual interface | GC9A01 round TFT | Attractive circular display format | More complex graphics layout |
Important Practical Notes
- Do not choose a display only by size
- Always check the controller chip before selecting a library
- Use SPI for faster graphic displays when possible
- Use I2C when simple wiring is more important than speed
- Check current consumption before powering displays from a small regulator
- Check logic voltage before connecting 5V and 3.3V boards
Conclusion
The right display is the one that matches the job. Character LCDs are practical for text, OLEDs are excellent for compact status screens, TFT LCDs are useful for color graphics, ePaper is ideal for static low-power information, and LED displays are best when brightness and visibility matter.
A good display choice saves pins, power, memory and development time. Before buying or designing around a display, check the controller chip, interface, voltage, current consumption and software support.