Choisir un écran LCD pour votre projet est une étape cruciale dans le développement de produits. Un mauvais choix peut conduire à des cycles de développement prolongés, cost overruns, and even hardware redesign. This guide will help you make informed decisions amidst complex parameters.
Why LCD Display Selection Is Crucial
The LCD display is the core window through which users interact with your device. An inappropriate choice can trigger multiple problems:
-
Performance Bottlenecks: Insufficient interface bandwidth causes video stuttering.
-
Increased Development Difficulty: Complex interfaces require deep hardware knowledge and challenging software debugging.
-
Wasteful Costs: Overpaying for high-performance screens or making an entire batch unusable due to improper selection.
Transition: To avoid these issues, understanding display interfaces is the first step.
Understanding LCD Interfaces: Core to the Right Choice
The display interface connects your main controller to the screen, determining data transmission method, vitesse, and system complexity. Here’s a breakdown of the main types:
Spice / I2C: Ideal for Small Microcontroller Projects
-
Spice (Interface périphérique série)
-
Avantages: Low pin usage, simple driving, excellent community support.
-
Drawback: Low bandwidth, suitable only for small screens.
-
Cas d'utilisation: Arduino, ESP8266/ESP32 projects.
-
-
I2C (Integrated Circuit Bus)
-
Avantages: Extremely low pin usage.
-
Drawback: Very low bandwidth.
-
Cas d'utilisation: Small OLEDs or character LCDs.
-
Transition: While SPI and I2C are simple, larger displays require higher-bandwidth solutions.
Parallel RGB: Embedded System Workhorse
-
High bandwidth and low latency, sufficient for smooth video.
-
Relatively simple to drive, intuitive logic.
-
Drawback: Complex PCB routing, susceptible to interference.
-
Cas d'utilisation: Embedded Linux systems, medium-size screens.
LVDS: Industrial and Automotive Stability
-
Excellent interference immunity and long transmission distances.
-
Requires additional sender/receiver chips.
-
Cas d'utilisation: Industrial panels, automotive infotainment, medical screens.
MIPI-DSI: Mobile Devices and High-Performance Applications
-
Extremely high bandwidth and low pin count.
-
Optimized for power consumption.
-
Cas d'utilisation: Smartphones, comprimés, high-end SBCs.
Core Parameters Beyond Interfaces
Even after choosing an interface, other parameters affect the display’s suitability.
Résolution: Not Always “Higher Is Better”
-
High resolution increases data volume, memory usage, and GPU load.
-
Recommendation: Balance screen size and viewing distance.
-
Classic embedded resolutions: 480×272 (4.3”), 800×480 (5-7”), 1024×600 (7-10.1”).
Screen Size and Touch Functionality
-
Size must fit the physical enclosure.
-
Touch options:
-
Resistive Touch: Low cost, can use any object, lower accuracy.
-
Tactile capacitif: Multi-touch, smooth experience, high transmittance.
-
Profondeur de couleur: Visual Quality vs System Load
-
RGB565 (16-bit): ~65,000 colors, sufficient for industrial UI.
-
RGB888 (24-bit): ~16.7 million colors, needed for videos/photos.
Transition: Once parameters are filtered, practical selection becomes easier.
Practical Selection Steps: Five Key Phases
-
Determine Main Controller Capabilities: Interface support, RAM, GPU.
-
Define Application Requirements: Text, graphique, video, touch needs.
-
Consider Environment and Budget: Indoor/outdoor, BOM constraints.
-
Filter Core Parameters: Type d'interface, résolution, screen size.
-
Evaluate Supply Chain: Stability, cost, documentation, sample support.
Conclusion: Matching Your Display to Your Project
-
Small MCU + Static Content: SPI/I2C
-
Embedded Linux + Medium Screens: Parallel RGB
-
Industrial/Automotive Large Screens: LVDS
-
High-Performance Mobile Devices: MIPI-DSI
Choosing an LCD is a systems engineering process balancing performance, complexity, and cost. Following these steps ensures your project avoids common pitfalls.
Transition: If you still have questions, leave a comment and our technical experts will assist.
