Which Rotary Display should I choose
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HMI Comparison

How to choose from 1.28-inch vs. 2.1-inch Rotary Display

— Choosing the Right HMI for Your Project

Selecting the right hardware is a critical first step for any Human-Machine Interface (HMI) project. The Rotary Screen, an innovative interactive solution, combines the intuitive nature of a touchscreen with the precise control of a physical knob, opening up new possibilities for developers.

This article provides a detailed comparison of two circular Knob Screen models from Elecrow's CrowPanel series: the 1.28-inch and the 2.1-inch versions. Through a direct analysis of their features and specifications, we'll help you make the most informed decision for your project's needs.

What is a Rotary Screen?

A Rotary Screen is an interactive module that integrates a high-definition touch display with a rotary encoder knob. It offers users two core interaction modes:

  • Touch Control: Modern UI operations like tapping and swiping via a capacitive touchscreen.
  • Knob Control: Precise value adjustment (e.g., volume, brightness) by turning the knob, and selection confirmation by pressing it, providing accurate physical feedback.

This dual-interaction model is particularly well-suited for applications requiring frequent and precise adjustments or menu navigation.

Shared Core Features

Before diving into the comparison, it's important to note that both products are built on the same powerful technology platform and share these core features:

  • High-Performance Processor: Both are equipped with the ESP32-S3R8 dual-core processor, running at up to 240MHz, with 8M PSRAM and 16M Flash to ensure smooth graphics and application performance.
  • Wireless Connectivity: Both feature built-in 2.4G Wi-Fi and Bluetooth Low Energy (BLE 5.0) to meet the networking demands of any IoT project.
  • Customizable UI: Full support for the open-source LVGL (Light and Versatile Graphics Library) allows developers to freely design and implement professional-grade user interfaces.
  • Broad Development Support: Compatible with a wide range of popular development platforms, including Arduino, ESP-IDF, PlatformIO, MicroPython, and ESPHome.
  • Expansion Interfaces: Both provide standard interfaces like UART, I2C, and FPC for easy connection to external sensors and modules.

Capability Radars

1.28-inch Screen

 

 
 
Performance
Display Quality
Portability
Expandability
Value
Info Density

2.1-inch Screen

 

 
 
Performance
Display Quality
Portability
Expandability
Value
Info Density

 

Detailed Specification Comparison

The table below provides a detailed breakdown of specifications for technical evaluation.

Feature CrowPanel 1.28-inch Rotary Screen CrowPanel 2.1-inch Rotary Screen
Picture

Product Link View Product View Product
Price $29.00 $35.70
Screen Size 1.28 inch 2.1 inch
Resolution 240 x 240 px 480 x 480 px
Core Chip ESP32-S3R8 ESP32-S3R8
Memory/Flash 8M PSRAM / 16M Flash 8M PSRAM / 16M Flash
Interaction Capacitive Touch + Rotary Knob (Rotate/Press) Capacitive Touch + Rotary Knob (Rotate/Press)
Dimensions 48 x 48 x 33 mm 79 x 79 x 30 mm
Weight 50g 80g
Special Feature LED Ambient Light -

Application Scenarios & Selection Guide

⭐ Choose the 1.28-inch Rotary Screen for:

Key Strengths: Compact, Portable, Cost-Effective, Integrated Ambient Light

  • Compact Desktop Gadgets: Perfect for creating a weather clock, stock ticker, or PC performance monitor without taking up much space.
  • Portable Devices: Ideal as the core interactive unit for handhelds, smart remotes, or DIY gaming devices.
  • Embedded Control Units: Excellent for direct integration into device panels as a dedicated knob for volume, brightness, or mode selection. The built-in LED can also serve as a status indicator.
  • Education and Prototyping: The lower cost and full feature set make it a great choice for teaching, training, and early-stage project development.

⭐Choose the 2.1-inch Rotary Screen for:

Key Strengths: Large Screen, High Resolution, Information-Rich UI

  • Smart Home Control Hubs: The larger, high-res screen allows for more complex, information-dense UIs that can display and control multiple devices simultaneously.
  • Data Visualization Dashboards: In industrial control, equipment monitoring, or scientific instruments, the high-resolution screen can clearly render charts, waveforms, and other complex data.
  • Applications Demanding High-Quality Visuals: When a crisp, detailed display is a key selling point of your product, the 2.1-inch screen is the superior choice.
  • Complex Standalone Devices: If your device needs to display multi-level menus, a full keyboard, or large amounts of text, the larger screen provides a much better user experience.

Making the Right Choice

Both of Elecrow's CrowPanel Rotary Screens are powerful HMI development modules, but they excel in different areas.

The CrowPanel 1.28-inch Rotary Screen is the ideal choice for compact and cost-sensitive projects. It stands out in portability, integration, and value, making it perfect for embedded installations and small standalone devices.

In contrast, the CrowPanel 2.1-inch Rotary Screen is designed for projects that demand a superior visual experience and greater information capacity. Its large, high-resolution screen makes it a formidable tool for control panels and data-intensive applications.

The final decision depends on your project's specific requirements for screen size, resolution, physical space, and budget. Assess your needs carefully to select the module that best fits your vision.