The LD2410B-P 24GHz radar presence sensor packs human-presence detection into a slim 35×7mm module with 1.27mm-spaced pins/pads, making it a useful option for projects where PCB space is limited. It uses FMCW radar to sense both normal body movement and the much smaller movements made by someone who is sitting, standing or otherwise remaining relatively still.
This makes it particularly useful where a conventional PIR sensor can fall short. PIR sensors detect changes in infrared energy as a warm body moves through their field of view, whereas the LD2410B-P can continue responding to subtle movement after someone has stopped walking around.
The module uses the LD2410-compatible UART protocol and works with established software including Nick Reynolds' LD2410 Arduino library and the ESPHome LD2410 component. Alongside a simple digital occupied/unoccupied output, its UART connection provides moving and stationary target information, approximate distance and radar energy data.
Bluetooth monitoring and configuration is also supported, allowing detection distance, sensitivity and other parameters to be adjusted using compatible software such as HLKRadarTool (Android / iOS).
As radar signals can pass through some non-metallic materials, the sensor may also pick up movement through thin doors, walls or plastic enclosures. Positioning the module carefully and adjusting its per-distance sensitivity settings can help limit detection to the area you actually want to monitor.
It's well suited to embedded occupancy sensing, automatic lighting, smart-home projects, equipment wake-up systems and other applications where detecting someone who isn't moving around much is important.
Important: the LD2410B-P uses 1.27mm pin spacing, so it will not plug directly into a standard 2.54mm solderless breadboard. Its narrow format is better suited to custom PCBs or just manually soldering wires to the pads. For easy breadboard prototyping, consider the LD2410C with 2.54mm pins.
This listing is available with a pre-soldered 1.27mm header or as an unsoldered/headerless module. The headerless version is useful when integrating the sensor directly into your own PCB, enclosure or wiring arrangement. Please select an option before adding to your cart.
Which presence sensor should I choose?
The LD2410C, LD2410B-P and LD2420 all use 24GHz radar for human-presence sensing, but they differ in physical layout, power requirements, configuration method and software support.
Note: 24GHz presence sensors are frequently marketed as “mmWave” devices. More precisely, a 24GHz signal has a wavelength of approximately 12.5mm, slightly longer than the conventionally defined millimetre-wave range of 10mm to 1mm.
The LD2410C offers similar LD2410 sensing and software support in a wider, breadboard-friendly format with 2.54mm pins.
The LD2410B-P (this product) provides LD2410 sensing, Bluetooth configuration and established software compatibility in a slim 35 × 7mm format, with headerless and pre-soldered options available.
The LD2420 is a separate native-3.3V design using its own serial protocol and threshold-based calibration system.
