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Kevin zhang
Kevin zhang

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Building an Industrial HMI with PX30 and a Custom 7-Inch TFT Display

#linux #programming #cpp #android

Building an Industrial HMI with PX30 and a Custom 7-Inch TFT Display

Introduction

Human-machine interfaces (HMIs) are essential components in modern industrial and embedded systems. From factory automation and medical terminals to smart vending machines and charging stations, a responsive and reliable HMI can dramatically enhance usability and efficiency. In this article, we’ll explore how to build a robust Android-based HMI using the Rockchip PX30 SoC and a custom 7-inch high-brightness TFT display.

This post will cover:

  • Why PX30 is ideal for embedded HMI systems
  • Selecting and customizing the TFT LCD panel
  • Device tree and display driver setup on Linux/Android
  • Hardware components and a sample BOM

7-inch TFT LCD

Why Choose PX30 for Industrial HMI?

The Rockchip PX30 is a quad-core ARM Cortex-A35 SoC designed for low-power applications, yet it offers sufficient performance for handling touch interfaces, video decoding, and rich UIs. It is widely used in interactive displays, smart appliances, and digital signage. PX30 provides:

  • Quad-core Cortex-A35 CPU at 1.3GHz
  • Native LVDS and MIPI-DSI support for display interfacing
  • Support for Android 8.1, Buildroot Linux, or Yocto-based OS
  • Rich peripheral support: UART, SPI, I2C, GPIO, PWM, etc.

Its power efficiency, compact package, and multimedia capabilities make it a strong candidate for industrial HMI products.

Display Selection: High Brightness and Customization

For industrial and semi-outdoor use, display readability is critical. Standard 250~300 nit TFTs are inadequate under sunlight or in high ambient light conditions. That’s why we selected the RK070CU01 TFT display:

  • Resolution: 1024 x 600
  • Brightness: 800 nits
  • Interface: LVDS
  • Viewing Angle: IPS Technology
  • FPC: Custom designed for specific connector/pinout needs

We worked with a panel manufacturer to customize the FPC cable for compatibility with our PX30 baseboard, avoiding additional adapters. The display also supports optical bonding to enhance outdoor visibility.

👉 Learn more about custom TFT display options:
Rocktech Custom TFT Display Solutions

Display Driver and Device Tree Configuration

PX30 supports various display outputs natively. In our case, LVDS was the most suitable interface. We configured the Buildroot environment to generate a lightweight Android image and adjusted the Device Tree Source (DTS) files accordingly.

Here is a simplified DTS node snippet for enabling LVDS and the RK070CU01 panel:

&lvds {
    status = "okay";
    rockchip,dual-channel = <0>;
    rockchip,data-mapping = "vesa-24";
    rockchip,output = "rgb";
    panel: panel {
        compatible = "rocktech,rk070cu01";
        backlight = <&backlight>;
        power-supply = <&vcc_lcd>;
        status = "okay";
    };
};

&backlight {
    brightness-levels = <0 64 128 192 255>;
    default-brightness-level = <255>;
    status = "okay";
};
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For touch functionality, we added support for the GT911 capacitive touch controller over I2C. Proper pinmux and interrupt/GPIO configuration ensured correct probe during boot.

👉 You can find the complete DTS and configuration examples here:
TFT Display Configs

Hardware BOM Overview

Below are the primary components used in our HMI reference design:

Component Description
PX30 SoC Quad-core ARM Cortex-A35
RK070CU01 7-inch IPS TFT, 800 nits, LVDS interface
GT911 Capacitive touch controller (I2C)
DDR4 2Gb Low-power memory for Android OS
eMMC 8GB Boot storage and system image
AXP209 PMIC for voltage regulation
Wi-Fi Module USB-based RTL8723BS or similar chipset
TPS51200 DDR termination regulator
Connector/FPC Custom FPC for display & touch interface

We kept the BOM optimized for industrial pricing while ensuring stable supply and long-term availability.

Industrial Applications and Scalability

The PX30 + 7" TFT combo is ideal for applications such as:

  • HMI Panels in Factory Automation
  • Charging Stations and EVSE Interfaces
  • Retail POS and Smart Vending
  • Medical Terminals and Diagnostics
  • Embedded Control Systems

The system supports OTA updates, UART debug logging, USB host/device operation, and even CAN bus extension with external transceivers.

Explore more high-brightness and industrial-grade displays:
👉 Industrial TFT Displays

Final Thoughts

Rockchip PX30, paired with a custom, high-brightness TFT LCD panel, provides a reliable foundation for building modern industrial HMIs. With native Android/Linux support, multiple display interfaces, and flexible BOM customization, it’s a great choice for OEMs and product teams looking to balance performance and cost.

If you're working on a similar project and want to avoid the pitfalls of poor display integration or kernel mismatches, start by aligning your panel interface and SoC capabilities early.

🛠️ Let me know if you'd like a detailed walkthrough of the DTS changes, Android BSP build guide, or display tuning with PWM backlight control!

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