In the wave of smart home, commercial, and industrial automation, precise, reliable, and non-contact "human perception" has become a core requirement. From determining whether someone is in a room to control lights and air conditioning, to detecting unauthorized entry into restricted areas, and tracking personnel movement to provide precise services, traditional infrared pyroelectric sensors are no longer sufficient. To address this, Chengdu Ebyte, leveraging its deep technological expertise, has launched the high-performance E54-24LD12 series millimeter-wave radar modules. With their high precision, multi-functionality, and low power consumption, they are redefining the boundaries of "intelligent perception."

Today, we will provide an in-depth analysis of four star products in the E54-24LD series: E54-24LD12A, E54-24LD12B, E54-24LD12C, and E54-24LD12D, helping you find the most suitable "intelligent eye."

I. Introduction to the E54-24LD12 Series Millimeter-Wave Radar Modules

The E54-24LD12 series operates in the 24GHz ISM free band, employing FMCW (Frequency Modulated Continuous Wave) technology. Combined with advanced radar signal processing and intelligent algorithms, it ensures stable and accurate detection of human targets, whether in vigorous motion, subtle movements, or stationary states.

1. E54-24LD12A: A Pioneer in Wide-Coverage Motion and Micro-Motion Sensing

Core Positioning: High-performance, wide-coverage motion and micro-motion human body detector.

Key Performance: Dimensions are 20mm × 20mm; detection distance up to 10 meters (moving human body); detection angle ±60°. It supports UART/GPIO interfaces, providing a visual host computer tool for flexible configuration of sensing distance, trigger threshold, and no-person reporting time.

Applicable Scenarios: Ideal for scenarios requiring medium-to-long-range, large-area human presence detection, such as: presence sensing in large conference rooms and shopping mall corridors, automatic switching of intelligent lighting, and intrusion detection in smart security systems.

2. E54-24LD12B: The Expert in Vital Sign Detection

Core Positioning: Optimized for detecting static vital signs (such as breathing and heartbeat), achieving true "vivid presence sensing."

Key Performance: More compact size (18mm × 15mm), reducing volume without sacrificing performance. Its maximum detection distance is 4.5 meters, possessing extremely high detection sensitivity, capable of distinguishing minute physiological activities from environmental interference. It also supports fine-tuning of sensitivity parameters using visualization tools.

Applicable Scenarios: Its primary application is in scenarios with stringent requirements for static human detection. Examples include: automatic opening and closing of smart toilet seats (determining if someone approaches/leaves), vital sign monitoring in smart elderly care mattresses, reminders for prolonged sitting at office desks, and "static personnel lingering" detection in high-end security systems.

3. E54-24LD12C: The King of Ultra-Low Power Battery Power

Core Positioning: An ultra-low power human presence sensor tailored for battery-powered IoT devices.

Key Performance: Power consumption is its biggest highlight, with a typical operating current as low as 65 microamps (μA). Combined with an intelligent intermittent operating mode, a single battery can last for several years. Detection distance is 6 meters (in motion). It uses a 19mm × 16mm package and supports IAP (In-Application Upgrade) for easy maintenance and upgrades.

Applicable Scenarios: Any "presence/absence" detection scenario requiring battery power and long-term operation. Typical applications include: wireless smart door locks (automatically wakes up when someone is at the door), battery-powered wireless sensor lights, low-power smart doorbells, and various mobile or low-power devices requiring adhesive installation and inconvenient wiring.

4. E54-24LD12D: High-Precision Multi-Target Trajectory Tracking Master

Core Positioning: Upgraded from "presence detection" to **"spatial positioning and trajectory tracking"**, achieving real-time positioning and tracking of single or multiple targets.

Key Performance: This is the most powerful model in the series, employing a one-transmitter, two-receiver antenna design. It can not only detect the presence of targets within a region, but also simultaneously track the real-time position (distance, angle) and speed information of up to three targets, reporting this data via a UART interface.

Key Performance: It boasts a data refresh rate of up to 10Hz, ranging accuracy of 0.15 meters, and angle accuracy of 2 degrees, providing intuitive trajectory visualization through accompanying host computer software. It also supports an "area monitoring" function, allowing users to customize key areas of focus.

Applicable Scenarios: Suitable for scenarios requiring spatial interaction and intelligent decision-making. For example: lights turn on when someone enters and off when they leave, with brightness adjusting to follow the person's movement; in smart commercial showrooms, screens display content based on the visitor's precise location and orientation; in smart bathrooms, toilet seats or faucets precisely adjust their movement based on a person's approach and departure.

II. Application Scenarios: From Concept to Implementation

Smart Home Full-Scene Interconnection: In the living room, the E54-24LD12D can be installed on the ceiling to track the location of family members in real time. When someone moves from the sofa to the dining room, the lighting and air conditioning direction can automatically adjust accordingly. In the bathroom, the E54-24LD12B can accurately sense when someone is approaching the toilet or sink, automatically lifting the lid, turning on the lights, and starting the exhaust fan, automatically resetting after the person leaves. In the bedroom, the E54-24LD12C can be used as a low-power night light, only illuminating at a low brightness when someone is detected getting out of bed, ensuring safety without disturbing sleep.

Smart Commerce and Building Automation: In the office, deploying the E54-24LD12B under each workstation can accurately determine whether a seat is occupied. Combined with an energy management system, it enables on-demand lighting and air conditioning control, achieving energy savings of up to 30%. In retail store entrances or near shelves, the E54-24LD12A can be used for customer flow statistics and hotspot area analysis. In conference rooms, the E54-24LD12D can track the location and movement of attendees, automatically controlling multi-zone lighting, curtains, and the orientation of display screen content.

Industrial Safety and Smart Elderly Care: In hazardous areas of factories (such as robot work areas), deploying the E54-24LD12D allows for the establishment of electronic fences. Once personnel enter the preset warning trajectory range, an audible and visual alarm is immediately triggered, and the equipment stops operating. In nursing home rooms, the E54-24LD12B's vital sign detection function can monitor the elderly person's breathing and heart rate non-contactly and imperceptibly while lying down. If abnormal prolonged stillness or absence of vital signs is detected, an alarm is immediately sent to the nursing station.

III. Common Problems and Core Solutions

1. Shortened or unstable detection distance?

Causes: A metal object or a strong reflective surface (such as a large area of glass or tile) is directly in front of the antenna, or the module is installed inside a metal casing.

Solution: Ensure that the area directly in front of the antenna is unobstructed. It is recommended to use a plastic casing (such as ABS or PP) with good transparency to 24GHz electromagnetic waves. 1. When installing multiple modules, avoid direct beam alignment and maintain a minimum spacing of 0.5 meters.

2. False alarms (reporting someone is present even when no one is present) or missed alarms (someone is present but not detected)?

Causes: Continuously swaying curtains, green plants, or rotating fans/air conditioner vents above the sensing area may interfere. It could also be due to improper trigger/hold threshold settings.

Solution: Optimize the installation environment and avoid continuously moving non-human interference sources. Use the visual host computer tool provided by EBITE, connect the module, and scan the ambient background noise using the "Data Acquisition/Analysis" function to recalibrate or automatically generate appropriate detection threshold values.

3. Module does not respond upon power-up or communication fails?

Causes: Incorrect power supply voltage (e.g., connecting 5V to A/B/C models that only support 3.3V), excessive power supply ripple, incorrect serial cable connection (TX/RX cross-connection), or incorrect baud rate setting (especially since the D model defaults to 256000bps instead of the more common 115200bps).

Solution: Strictly verify the power supply voltage range in the product manual and use a stable power supply. When using a USB-to-TTL adapter, ensure TX-RX are cross-connected, GND is a common ground, and select the correct COM port and baud rate in the PC's serial port tool.

4. How to integrate with my main control system (such as a microcontroller or Raspberry Pi)?

Brief description: All E54-24LD series modules provide a standard UART serial communication protocol.

Steps: Cross-connect the serial port pins of the main control MCU with the module's TX/RX pins. According to Chapter 5, "Communication Protocol," in the product manual, write a program to parse the data frames periodically reported by the module (e.g., AA FF 03 00 ... 55 CC format for the D model) to obtain information such as human body status, distance, angle, and coordinates, thereby implementing your business logic.

The E54-24LD12A/B/C/D series millimeter-wave radar modules, with their complete product range, superior performance indicators, and extensive development support, provide a full-stack solution for intelligent upgrades across various industries, from "sensing presence" to "sensing trajectory." Whether for consumer applications seeking ultimate cost-effectiveness or industrial and commercial projects demanding high reliability, this series offers an ideal solution.