So you've got a project in mind — maybe a handheld device, a sensor readout, or a custom control panel — and you know you need a display. You search "TFT LCD module" and suddenly you're staring at a wall of sizes, interfaces, and specs with no obvious starting point.

This guide cuts through that. We'll walk through the four things that actually matter when picking a TFT LCD module, and by the end you'll know exactly what to look for.

Start with size — but think about your enclosure first

The instinct is to pick a screen size based on how much information you want to display. That's backwards. Start with your physical enclosure and work inward.

A 3.5" display might look perfect on a breadboard, but if your final product has a 60mm wide housing, you've got a problem. Measure your available panel cutout first, then match a module to it.

Here's a rough breakdown of where common sizes land in real-world projects:

• 0.96" – 1.3" — Wearables, small sensor nodes, badge-style displays. Minimal real estate, but perfectly readable for a few lines of data.
• 1.8" – 2.4" — The sweet spot for handheld devices and DIY instruments. Big enough to show a UI, small enough to keep the build compact.
• 2.8" – 3.5" — Touchscreen territory. Common in industrial HMIs, portable testers, and Raspberry Pi projects.
• 4.0" – 5.0" — Panel PCs, in-vehicle displays, home automation controllers.
• 7.0" – 10.1" — Full tablet-scale. Used in kiosks, medical carts, and industrial consoles.

If you're unsure, go one size smaller than you think you need. Oversized displays are one of the most common early mistakes in hardware prototyping.

Resolution: don't optimize for specs, optimize for legibility

Higher resolution sounds better on paper. In practice, it only matters relative to screen size.

A 240×320 display at 1.8" gives you roughly 222 PPI — sharp enough for clean icons and readable text. That same resolution on a 3.5" panel drops to about 114 PPI, which starts looking coarse if you're rendering small fonts.

A simple rule: if you're displaying text smaller than 12pt equivalent, or rendering detailed graphics, aim for at least 150–200 PPI. For basic status readouts and large icons, anything above 100 PPI is fine.

Don't chase 4K on a microcontroller project. Your MCU will bottleneck long before the display does.

Interface: this is where most people get tripped up

The interface determines how your MCU communicates with the display — and if they don't speak the same language, nothing works, regardless of how good the panel is.

SPI (Serial Peripheral Interface): The most beginner-friendly option. Uses 4–5 pins, works with almost every microcontroller (Arduino, ESP32, STM32, Raspberry Pi). Slower than parallel, but for displays up to about 2.4", the speed difference is invisible to the human eye.

MCU Parallel (8080/6800) Faster data transfer than SPI. More pins required (8 or 16 data lines). Preferred when you need faster refresh rates — scrolling maps, real-time waveforms, video.

MIPI DSI High-speed serial interface used in larger displays (5" and up). Common in systems with dedicated display processors. Not typically used in bare MCU projects.

LVDS / RGB is used in larger industrial panels. Requires a display controller IC between your processor and the screen.

For most maker and embedded projects under 3.5", SPI or 8080 parallel covers 95% of use cases. If you're using an ESP32 or STM32, SPI is usually the easiest starting point.

Driver IC: the unsung detail

Every TFT module has a driver chip that handles the actual pixel addressing. The driver IC determines which software libraries will work out of the box.

Common ones you'll encounter:

• ILI9341 — The most widely supported driver in the maker ecosystem. If you want the most library support (Adafruit GFX, LVGL, TFT_eSPI), look for this one.
• ST7789 — Excellent for small, high-resolution displays. Popular on 1.3" and 1.54" square panels.
• ILI9488 — Common on 3.5" modules with 18-bit color.
• ST7796 — Good choice for 4" displays, faster than ILI9488 in most configurations.

If you're buying from a supplier and the driver IC isn't listed in the spec sheet, ask before you order. Debugging display issues caused by a misidentified driver IC is a frustrating way to spend a weekend.

Touch or no touch?

Resistive touch is cheaper and works with a stylus or gloved hands — good for industrial and outdoor use. Capacitive touch is smoother and supports multi-touch gestures, but costs more and requires a separate controller IC (typically GT911 or FT6236).

If touch isn't core to your UI, skip it. Every additional component is another potential failure point in a prototype.

Browse POLCD's TFT LCD module range

We manufacture TFT LCD modules from 0.96" to 10.1", covering SPI, MCU parallel, RGB, and MIPI interfaces. Every module ships with a datasheet and sample code. If you're not sure which one fits your project, send us your specs, and we'll point you in the right direction.

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