ST7789 vs ILI9341 TFT Display Controllers

HZY Engineering Notes · 2026-09-06

Choosing a driver IC for a small TFT module often comes down to two familiar part numbers: ST7789 and ILI9341. Both are single-chip controllers with integrated display RAM, both target small-to-medium panels, and both appear on a large share of the modules sold into embedded products. Yet they are not interchangeable in every design. The differences in native resolution, interface options, and ecosystem depth shape which panel sizes are readily available and how much work the firmware side will take.

This article compares the two controllers from a hardware engineering and sourcing perspective: what resolutions they typically drive, how their SPI and parallel interfaces differ, how mature their software support is, and how those factors influence module availability in the 1.3 to 2.4 inch range.

What these controllers actually do

The ST7789 (including the ST7789V and ST7789V2 variants) and the ILI9341 are display driver ICs with on-chip frame memory. The host microcontroller does not stream pixels continuously as it would with an RGB panel; instead it writes commands and pixel data into the controller's RAM, and the controller scans the panel from that memory. This architecture is what makes both parts well suited to SPI-based designs, where pin count and PCB routing are at a premium.

Because the controller owns the refresh, the host interface can be relatively slow without causing flicker. The trade-off is that the host must transfer the full frame whenever content changes, which is why interface width and bus speed dominate how responsive the display feels in animated or scrolling use cases.

Both parts support a command set that has become a de facto standard in the small-TFT world. Initialisation sequences, rotation settings, and partial-window writes are widely documented, and most embedded graphics libraries include drivers for one or both.

Typical resolutions and panel sizes

The resolution question is usually the first filter in a design. The two controllers occupy adjacent but distinct territory.

ILI9341

The ILI9341 is historically associated with 240x320 panels, the classic 2.2 inch and 2.4 inch portrait QVGA format. It also drives 240x240 and similar small formats. In practice, when engineers picture a 2.4 inch SPI TFT with a touchscreen, the ILI9341 is the controller that established that category. It supports 16-bit and 18-bit colour, and its memory layout is arranged around a 240-pixel source driver.

ST7789 and ST7789V2

The ST7789 family covers a wider spread of small formats. It is very common on 240x240 round and square panels in the 1.2 to 1.5 inch range, on 240x280 and 240x320 rectangular panels, and on some 135x240 and 172x320 variants. The ST7789V2 revision has become a default choice for 1.3 inch 240x240 modules, a format that has largely displaced older 1.3 inch panels in new designs.

For a buyer, this translates into a practical rule of thumb: if the target is a 240x320 rectangle in the 2.0 to 2.4 inch class, both controllers appear on the market, with the ILI9341 more entrenched in legacy designs and the ST7789 increasingly common in newer ones. If the target is 240x240 or a smaller square or round format in the 1.3 to 1.5 inch class, the ST7789 family dominates module availability.

At the upper end of the small-TFT range, neither controller is the right answer. Panels at 4.3 inch and above, or higher-resolution formats, typically move to RGB, MIPI, or QSPI interfaces with different controllers. Our range of 2.4 inch and larger TFT displays shows where these interface transitions tend to occur.

Interface styles compared

Both controllers offer SPI and a parallel MCU interface, but the details matter when selecting a module.

SPI variants

The ILI9341 supports a four-wire SPI mode (clock, data, chip select, and data/command) plus a three-wire nine-bit mode. Write throughput over SPI is limited by the single data line, so full-screen updates at 240x320 in 16-bit colour take a noticeable amount of time even at high clock rates. Partial updates and region writes are the usual mitigation.

The ST7789 family adds broader support for wider SPI configurations. Many ST7789 modules are offered with quad SPI options in addition to standard four-wire SPI, and the controller supports higher clock rates in many configurations. In practice, this means an ST7789-based module can be more comfortable for applications with frequent partial redraws, such as gauges or simple animations, while a standard four-wire ILI9341 module remains adequate for menus and status displays updated at human-readable rates.

If SPI bus design is new to your team, our overview of SPI TFT display interfacing covers signal naming, daisy-chaining considerations, and typical timing constraints.

Parallel interfaces

Both controllers support an 8080-style parallel MCU interface, typically 8-bit or 16-bit. Parallel mode offers much higher pixel throughput than SPI but costs a large number of GPIO pins and more complex PCB routing. On small modules, parallel mode is usually reserved for designs where the host has a dedicated external memory bus and the display is updated frequently.

Other signals

Both controllers include a TE (tearing effect) output that can be used to synchronise host writes with the panel refresh, a useful feature for avoiding visible tearing in animated content. Backlight control is not part of either controller and is handled at the module level, typically via a boost converter and a PWM-driven LED driver.

Ecosystem maturity

Ecosystem here means three things: the availability of driver code in common embedded frameworks, the volume of reference designs and example projects, and the stability of documentation.

The ILI9341 has one of the deepest software ecosystems in the small-TFT space. Drivers exist for essentially every embedded graphics library and RTOS integration, and a very large body of example code and community discussion is available. A new design using an ILI9341 module is unlikely to encounter a software unknown.

The ST7789 ecosystem is also mature, particularly for the 240x240 formats that have become standard in wearable and compact instrument designs. Driver support in popular libraries is generally present, though variant handling deserves attention: ST7789, ST7789V, and ST7789V2 differ in some initialisation details, and a driver written for one variant may need small adjustments for another. Buyers should confirm the exact variant on the module datasheet and check that the chosen library covers it.

One practical difference is that the ILI9341's long history means more community-verified workarounds for edge cases, such as colour order quirks or offset windows on specific panels. The ST7789's broader interface options mean more configuration surface, which is an advantage for experienced teams and a small learning curve for others.

How the choice affects module availability

Controller selection is not only a firmware decision; it determines what a buyer can actually source.

• In the 2.2 to 2.4 inch 240x320 class, both controllers are widely available. Legacy designs often specify ILI9341, while newer module designs increasingly use the ST7789 family.
• In the 1.3 to 1.5 inch 240x240 class, ST7789 variants are the mainstream option. The 1.3 inch 240x240 ST7789V2 SPI module has become a volume format, and alternatives with other controllers are less common.
• In round formats, ST7789 and GC9A01-class controllers cover most of the market, with the ST7789 handling many square and near-square panels.
• In 1.8 to 2.0 inch 128x160 and 240x320 formats, both controllers appear, with availability varying by panel supplier and touch options.

For buyers, the practical implication is that specifying a controller outside the mainstream for a given size can reduce the number of available module options, extend lead times for custom builds, and complicate second-sourcing. Conversely, aligning with the mainstream controller for the chosen size usually widens the supplier pool.

Our small LCD display range spans these formats and includes modules built around both controllers, so the size and resolution decision can be made first and the controller matched to it.

Selection guidance

The following general guidance reflects how these controllers are typically positioned in module design:

• Choose ST7789 when the target is a 1.3 to 1.5 inch 240x240 panel, a small round display, or a design where wider SPI options and higher interface flexibility are valuable.
• Choose ILI9341 when the target is a 240x320 panel in the 2.2 to 2.4 inch class, or when the design benefits from the largest possible body of existing driver code and reference material.
• Do not choose either controller for panels above roughly 2.8 inch or for resolutions beyond 320x240 unless the specific module datasheet confirms support; larger or higher-resolution panels typically use RGB, MIPI, or QSPI interfaces with different controllers.
• Confirm the exact controller variant, colour order, and interface mode from the module datasheet before finalising firmware, since two modules with the same controller family can differ in initialisation.

Interface and controller combinations across a wider range

It helps to see where these two controllers sit relative to the rest of the small-TFT landscape. Modules in the 1.85 inch 320x386 class may use QSPI for higher throughput. Panels at 4.3 inch 800x480 typically use an RGB interface. Bar-type and high-resolution formats move to MIPI. For standard 128x64 monochrome graphic modules, controllers such as the ST7567 remain the norm, and character modules continue to use HD44780-command-set parts (ST7066U class).

This diversity is why module selection is usually a conversation about the whole stack, not just the controller. Backlight brightness, touch options, FPC pinout, and operating temperature range all interact with the controller choice, and a change in one can force a change in another.

Working with a module supplier

For custom projects, the controller decision should be made alongside the panel specification rather than after it. Suppliers who build modules around a range of controllers can advise which combination is currently mainstream for a given size, which affects both sample availability and long-term supply stability.

A typical custom process starts with drawings in about three days, followed by samples in about two weeks and mass production in about five to six weeks. Standard listed models are often available from very small quantities, which allows a controller and panel combination to be evaluated on real hardware before a production commitment.

Shenzhen HZY Photoelectric Technology (brand HZY) has designed and manufactured LCD modules since 2011, with TN, STN, and VA panel capability plus COG, COB, and TFT assembly lines. TFT modules span 0.71 inch to 10.1 inch, and common drivers across the range include the ST7789/ST7789V2, ST7735S, ST7701, and others, alongside interfaces from SPI and QSPI to RGB and MIPI. Modules undergo 100 percent functional inspection before shipment, and quality and environmental systems include ISO 9001, IATF 16949, and ISO 14001, with certificates available upon request.

If you are weighing an ST7789 against an ILI9341 for a new design, or need a module in the 1.3 to 2.4 inch range with a specific interface, touch option, or brightness target, send your panel requirements or target specification to our contact page. We can confirm which controller and panel combinations are currently available and what a custom build would involve.