Clever ESP32 Weather Display Uses Millimeter Wave Radar to Solve the Smart Home Power Problem

The creation of custom smart home displays has long been a favorite pastime for DIY electronics enthusiasts and tinkerers alike. Whether mounted on a kitchen wall, placed on a bedside table, or set beside a home office desk, these devices offer at-a-glance access to essential information like current conditions, local time, and upcoming forecasts. However, builders of these custom gadgets have historically faced a persistent, frustrating dilemma: how to handle a screen that is constantly powered on.

For many makers, energy conservation is a primary concern. When minimizing power draw is the ultimate goal, enthusiasts often turn to e-ink displays. Because electronic paper screens only require power when changing their visual state and can render static information with minimal electricity, they make ideal candidates for energy-efficient setups. Unfortunately, e-ink panels often come with limitations regarding high refresh rates, color reproduction, and dynamic animations.

Faced with these trade-offs, one clever developer and Redditor known online as sudu1988 has pioneered an alternative approach to energy savings. Rather than sacrificing display quality or relying entirely on low-power panel technology, this innovative project introduces a hardware-level solution: a sensitive radar module designed to awaken the screen only when a human presence is detected nearby.

This ESP32 Weather Display Has a Smart Power-Saving Trick Up Its Sleeve

The project, which was recently shared on the vibrant ESP32 community forum on Reddit, showcases a sophisticated desktop weather station that pulls real-time meteorological data directly from Open-Meteo. Beyond providing users with accurate local time and comprehensive weather updates, the device’s standout feature is its optional human presence detection system. Instead of remaining illuminated around the clock—wasting electricity and potentially causing a distraction in dark rooms—the display stays completely dark until someone approaches close enough to actually read the information presented on the screen.

In detailing the technical specifications of the build, sudu1988 explained the careful selection of components required to bring the smart weather display to life. At the heart of the hardware setup is a Freenove FNK0103S development board, which is powered by an ESP32-WROOM-32E microcontroller. This specific board integrates Wi-Fi connectivity, display support, and touch capabilities into a single cohesive module, significantly reducing the complexity of external wiring and making the physical assembly much more manageable for DIY builders.

Visual output and user interaction are handled by a 4-inch ST7796 display paired with an XPT2046 resistive touchscreen. This combination allows for a responsive, vibrant interface that goes far beyond simple static data readouts. However, the true innovation of the project lies in its power management strategy. To solve the perpetual illumination problem, sudu1988 integrated a Hi-Link HLK-LD2410C millimeter wave human presence radar. This specialized sensor constantly scans the immediate environment for human movement and proximity, ensuring that the power-hungry color display only draws electricity when it is actively needed by a viewer.

To house these diverse electronic components securely and aesthetically, the developer also designed a custom enclosure and stand that can be easily fabricated using a standard 3D printer. This thoughtful integration of hardware and housing elevates the project from a messy breadboard prototype into a polished, consumer-ready appliance that looks right at home on a desk or mantle.

More Projects Should Adopt This Technology

Beyond its clever proximity-sensing capabilities and efficient power management, the ESP32 weather station has been designed with a high degree of international versatility. Recognizing that tech enthusiasts span the globe, sudu1988 built robust localization support into the system. The display accommodates a wide variety of regional settings, offering support for multiple country codes and languages including Great Britain, Spain, Germany, France, Ukraine, Sweden, Italy, and Russia.

Furthermore, the software allows users to seamlessly toggle between different time formats and temperature units. For international users who are tired of mentally converting Celsius to Fahrenheit—or vice versa—whenever they check a digital forecast, this flexibility provides a welcome convenience. By combining modern microcontroller capabilities, precise millimeter wave radar technology, and thoughtful software localization, this DIY weather display demonstrates how creative engineering can overcome classic hardware limitations in the smart home space.