LD1115H24G Human Presence Sensor Module 24 GHz millimeter wave micromotion detection module with TTL serial communication What this module does The LD1115H24G is a compact millimeter wave radar sensor designed to detect human presence and very small motions. Operating at 24 GHz, it senses micromovements that are difficult for traditional PIR sensors to detect. Data and events are delivered over a TTLlevel serial interface for straightforward integration with microcontrollers and embedded systems. Key benefits and why you need it Reliable nonoptical presence detection: Uses 24 GHz radar to work independently of visible light, making it effective in dark or lowvisibility conditions. Sensitive micromotion sensing: Detects very small movements for improved detection of stationary people making minimal motion compared to conventional motion sensors. Easy system integration: TTL serial communication provides direct compatibility with common microcontrollers and singleboard computers for rapid prototyping and deployment. Compact, boardlevel form factor: Small module size fits into tight enclosures and embedded products without significant rework. Fast response for realtime applications: Radarbased sensing provides lowlatency detection suitable for responsive control systems. Important attributes Function: Human presence detection and micromotion sensing using millimeter wave radar technology. Frequency: 24 GHz operation for precise micromotion detection. Communication: TTLlevel serial interface for data and control signals. Compatibility: Designed to interface with standard TTL serial ports found on microcontrollers and development boards. Construction: Boardlevel module suitable for PCB integration or mounting inside electronic housings. Performance: Sensitive to micromovements and designed for fast detection and event reporting. Integration and usage notes Connect the module to a microcontroller or singleboard computer using TTL serial lines for command and data exchange. Mount the module where it has a clear field of view toward the monitored area. The millimeter wave signal does not rely on ambient light. Typical integration tasks include reading presence events, logging motion timestamps, or using the module to trigger actuators or system state changes. Practical applications and scenarios Smart lighting and occupancy control: Automatically turn lights on or off based on detected presence, improving convenience in hallways, closets, and restrooms where small movements need to be detected. Automated access and security systems: Trigger door control or alert systems when human presence is detected in a monitored zone, including lowlight or visually obscured conditions. Interactive devices and robotics: Provide a sensitive proximity or wakeup sensor for kiosks, robots, or consumer electronics that must respond to subtle human motion. Why choose this module The LD1115H24G offers a compact, radarbased approach to presence sensing that complements or replaces optical and PIR sensors in applications where small movements, low light, or nonvisual detection are important. Its TTL serial interface and boardlevel design make it practical for rapid integration into embedded projects and commercial products.