In the era of rapid technological advancement, smart home products are constantly evolving. As a key component, smart toilets are gaining increasing favor among consumers. From basic functions like seat heating and water washing to today’s complex intelligent operations, the development of smart toilets reflects how technology enhances quality of life. Among these advancements, the application of radar modules has become a critical breakthrough for achieving higher-level intelligence in smart toilets.
1. Unveiling the Working Principle of Radar Modules
The working principle of radar modules is based on the magic of electromagnetic waves. Like a tireless "little guard," it continuously emits electromagnetic waves of specific frequencies into the surrounding space. When these waves encounter an object, they reflect back like a ball hitting a wall, forming echo signals. The receiver in the radar module quickly captures these echoes and performs complex, precise data processing. By analyzing characteristics of the echo signals—such as return time and frequency changes—the radar module can accurately obtain key information about the object, including distance, movement speed, orientation, and approximate size.
Take car reversing radar as an example, which uses ultrasonic ranging (similar to radar’s electromagnetic wave-based principle, both relying on wave reflection). When a driver reverses, sensors on the rear bumper emit ultrasonic waves. Upon encountering an obstacle, the waves reflect back, and the sensors process the echoes through complex algorithms to determine the obstacle’s position. The system then displays the distance to the driver via a monitor and emits warning signals of varying frequencies, assisting safe parking. While the radar modules in smart toilets differ in working frequency bands and signal processing, the core principle of using wave reflection to obtain object information remains the same.
2. Diverse Application Scenarios of Radar Modules in Smart Toilets
(1) Automatic Lid Opening/Closing
Traditional toilets require users to manually lift or lower the lid—a cumbersome process that poses hygiene risks in public restrooms. Radar modules transform this: when a user approaches within the module’s effective sensing range, it detects changes in electromagnetic wave reflection caused by the human body. A high-performance processor analyzes these signals to confirm human presence and triggers the control system, which drives a motor to automatically raise the lid. After use, when the user leaves, the radar detects their departure and signals the lid to close. This hands-free operation enhances convenience and hygiene. For example, Holtek’s HLK-LD2411 radar module senses human approach/exit within 2 meters, triggering GPIO signals to a microcontroller for automatic lid control, significantly improving user experience.
(2) Automatic Flushing
After use, automatic flushing is critical. When the user stands up and moves away, the radar module detects the change in human position, signals the flushing system, and initiates a preset program to adjust water intensity and angle for thorough cleaning. This eliminates the need for manual button pressing, reducing hygiene risks and forgetfulness. Advanced models even use radar data (e.g., usage time, sitting posture) to intelligently adjust water volume and pressure for personalized flushing, enhancing smart functionality.
(3) Presence Sensing and Energy-Saving Mode
Prolonged standby of smart toilets wastes energy. Radar modules address this with presence sensing: if no human is detected for a period, the module signals the toilet to enter energy-saving mode, turning off or reducing power to non-essential functions (e.g., seat heating, lighting). When the user returns, the radar detects their presence and restores normal operation. This balances convenience with energy efficiency, aligning with sustainability goals and saving electricity costs.
(4) Automatic Light Control
To improve nighttime or low-light usage, some smart toilets feature lighting. Radar modules coordinate with the lighting system to turn lights on when detecting an approaching user and off after they leave. This avoids energy waste from forgotten lights while adding a touch of technological warmth to the bathroom.
3. Advantages of Radar Modules for Smart Toilets
(1) Precise Sensing Performance
Compared to traditional infrared pyroelectric sensors, radar modules offer higher accuracy and stability. Infrared sensors are prone to interference from environmental temperature and light—for example, struggling to detect humans in summer when ambient temperatures approach body heat. Radar modules, based on electromagnetic wave reflection, are less affected by environmental factors, reliably detecting human position and movement in extreme temperatures or lighting conditions. This consistency ensures stable, uniform user experiences.
(2) Flexible Sensing Distance Adjustment
Different scenarios require varying sensing distances. Radar modules allow easy adjustment of detection ranges via internal parameter settings or external software. In small home bathrooms, shorter ranges prevent accidental triggering; in large public restrooms, longer ranges enable proactive service. This flexibility adapts smart toilets to diverse environments and user needs.
(3) Strong Anti-Interference Capability
In homes with multiple electronic devices, electromagnetic interference is common. Radar modules use mature CMOS technology with single-chip integration and self-calibration, filtering out ambient noise to focus on human-reflected signals. Even near high-interference devices like microwaves or hairdryers, radar modules accurately detect humans, ensuring reliable operation. This robustness guarantees stable performance in complex environments, supporting the toilet’s intelligent functions.
