What is the maximum size of external display screen supported by the control board of the 14KW dual-gun AC charging pile? Can the human-computer interaction interface be customized?

The control board of the 14kW dual-gun AC charging pile supports customization capabilities for the size of the external display screen and the human-computer interaction interface, depending on the display interface type of the MCU, video memory bandwidth, and firmware openness. In 2026, mainstream solutions will cover a full range from 2.8-inch monochrome screens to 10-inch color touch screens, but there will be significant differentiation in customization depth.

1. The hardware interface determines the upper limit of size

• SPI interface: The MCU drives the display screen through the SPI bus, with a typical speed of 10-20MHz. It supports 2.8-3.5 inch TFT color screens with resolutions of 320×240 or 480×320, such as the ILI9341 driver chip. The frame rate is limited, with a full-screen refresh rate of about 10-15fps, suitable for static UI or simple animations. The SPI bus is shared by multiple devices (Flash, metering chips), and CS line switching increases latency. For screens larger than 3.5 inches, a separate SPI or reduced frame rate is required.

• RGB parallel interface, with MCU directly outputting RGB data + synchronization signals (HSYNC/VSYNC/DE/PCLK). Supports 4.3-7 inch TFT color screens with resolutions of 800×480 or 1024×600, such as AT070TN92. PCLK typically operates at 27-33MHz, achieving a smooth frame rate of 60fps. Requires dedicated GPIO (16-24 pins), putting a strain on MCU pin resources, with dense routing on a 4-layer PCB.

• LVDS interface, RGB to low-voltage differential signaling, strong anti-interference, suitable for long distances. Supports 7-10 inch high-definition screens with resolutions of 1280×800 or 1920×1080. Requires a dedicated LVDS bridge chip (such as THC63LVD827), with a cost of 15-25 yuan. MIPI DSI high-end solution, mobile phone-grade interface, 10-inch and above 2K screens, but 7kW/14kW pile MCUs do not have this capability, only used in flagship or advertising piles above 22kW.

II. Typical configuration of 14kW dual-gun control board

• Economical model, featuring a SPI 2.8-inch screen, with a cost of 20-35 yuan. It displays charging status, battery level, and fault codes, and the UI is fixed and non-replaceable.

• Standard model, RGB 7-inch screen, costing 80-150 yuan, featuring multi-point capacitive touch, supports scanning, card swiping, start/stop, and history recording.

• Flagship model, LVDS 10-inch screen, costing 200-350 yuan, featuring high-definition video advertising, multi-language support, V2G visualization, and real-time photovoltaic power monitoring.

III. User-defined depth of human-computer interaction

• Firmware-locked type, with UI images, layout, and colors burned into Flash, allowing only manufacturers to perform OTA updates and not allowing users to make changes. Representatives: XinCheng Technology, Early TeDian, and State Grid Pile.

• The configuration is open-type, with the manufacturer providing a PC-side UI editor, and the operator changing the Logo, color scheme, and language pack, which are distributed via USB flash drive or OTA. Representatives include XinCheng Technology and Xingxing Charging.

• Fully open-source, running LVGL or TouchGFX, allowing users to design their own UI and compile and flash C code. Representatives: Geek Modification, OpenEVSE community.

IV. Customized technical boundaries

• Image resources, in BMP/JPEG/PNG formats, need to be converted according to the decoding capability of the MCU. The full-screen background image for a 7-inch screen is approximately 500KB, and 2-4MB should be reserved for Flash.

• Font library, Chinese GB2312 about 200KB, multi-language Unicode requires 1-2MB, vector font (TTF) requires FPU accelerated rendering.

• Regarding animation effects, SPI screens do not support complex animations, RGB screens can utilize DMA2D hardware acceleration, and LVDS screens can play 720p videos.

• Touch response, capacitive screen I2C interface, coordinate reporting rate of 100Hz, gesture recognition handled by firmware or UI framework.

V. Special requirements for 14kW dual-gun

• Dual-gun status display on the same screen, with the 7-inch screen divided into left and right sections, each displaying one gun: voltage/current/power/SOC/remaining time.

• Master-slave switching, with one gun charging while the other is in standby mode, the UI focus automatically follows, and touch operations do not conflict.

• Commercial interludes, flagship 10-inch screen, full-screen advertisements during charging, instant switching between plugging in and unplugging, revenue sharing model.

VI. One-sentence summary

• The control board for the 14kW dual-gun charging pile supports SPI up to 3.5 inches, RGB up to 7 inches, and LVDS up to 10 inches. Human-computer interaction has evolved from "manufacturer-closed" to "operator-configurable" to "geek-open source", showing a three-tier differentiation. By 2026, the mainstream will be the 7-inch RGB touch screen + open configuration type, with a cost of 100-150 yuan.

• It meets the requirements of dual-gun display + scanning payment + brand customization. Full open source is only suitable for tech enthusiasts, and closed firmware is being phased out by the market.

The AC charging pile control board produced by XinCheng Technology is of high quality and reasonable price. Welcome to inquire and purchase!