{"product_id":"ld2420-24ghz-human-presence-sensor","title":"LD2420 24GHz Human Presence Sensor","description":"\u003cp\u003eThe \u003cstrong\u003eLD2420 24GHz radar presence sensor\u003c\/strong\u003e is designed for indoor projects that need to know whether a person is in a monitored area, including when they are making only small movements. It uses FMCW radar rather than changes in body heat, allowing it to detect normal movement, subtle movement and the small motions made by someone sitting or standing relatively still.\u003c\/p\u003e\n\u003cp\u003eThe module provides a straightforward digital presence output alongside a UART interface for reading presence, approximate target distance and radar energy data. Its detection area can be adjusted using configurable distance gates, with separate trigger and hold thresholds to help balance reliable detection against unwanted activations.\u003c\/p\u003e\n\u003cp\u003eThe LD2420 uses its own communication protocol and is supported by the \u003ca href=\"https:\/\/esphome.io\/components\/sensor\/ld2420\/\" rel=\"noopener\" title=\"ESPHome LD2420 component\" target=\"_blank\"\u003eESPHome LD2420 component\u003c\/a\u003e. Community-developed Arduino libraries are also available (although some limit the sensor's features), \u003cstrong\u003ehowever the LD2420\u003c\/strong\u003e \u003cstrong\u003eis not compatible with software libraries written specifically for the LD2410 family\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eUnlike a conventional PIR sensor, radar does not need a warm body to move across distinct detection zones. This makes the LD2420 useful for occupancy sensing in offices, living spaces and work areas where someone may remain seated for an extended period.\u003c\/p\u003e\n\u003cp\u003eRadar can pass through some non-metallic materials and may detect movement outside the intended area. Careful positioning and adjustment of the distance gates and thresholds can help reduce detections through thin walls, doors or enclosures.\u003c\/p\u003e\n\u003cp\u003eThe module operates directly from \u003cstrong\u003e3.3V\u003c\/strong\u003e and is well suited to ESP32 and other 3.3V microcontroller projects. It \u003cstrong\u003ecomes with a pre-soldered 2.54mm header\u003c\/strong\u003e and is suitable for use with \u003ca href=\"\/collections\/solderless-breadboards\" title=\"Solderless Breadboards\"\u003ebreadboards\u003c\/a\u003e and \u003ca href=\"\/collections\/jumper-wires\" title=\"Jumper Wires\"\u003ejumper wires\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eWhich presence sensor should I choose?\u003c\/h2\u003e\n\u003cp\u003eThe LD2410C, LD2410B and LD2420 are all 24GHz radar presence sensors capable of detecting normal movement and the smaller movements made by a relatively stationary person. The main differences are their physical format, supply requirements, configuration options and software compatibility.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe \u003ca href=\"\/products\/ld2410c-24ghz-human-presence-sensor\" title=\"LD2410C\"\u003eLD2410C\u003c\/a\u003e is a convenient general-purpose option, with a compact breadboard-friendly layout, Bluetooth configuration and broad support from existing LD2410 Arduino and ESPHome integrations.\u003c\/li\u003e\n\u003cli\u003eThe \u003cstrong\u003eLD2410B\u003c\/strong\u003e provides similar LD2410 sensing and software compatibility in a longer, narrower format, with both pre-soldered and headerless variants available.\u003c\/li\u003e\n\u003cli\u003eThe \u003cstrong\u003eLD2420 (this product)\u003c\/strong\u003e is a separate 3.3V design with its own serial protocol and threshold-based calibration system, making it better suited to projects that specifically require native 3.3V power or its different detection characteristics.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eNote\u003c\/strong\u003e: Sensors of this type are often described commercially as “mmWave” sensors. Strictly speaking, 24GHz has a wavelength of approximately 12.5mm, just outside the conventionally defined millimetre-wave range of 10mm to 1mm.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch3\u003ePresence sensor comparison\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; height: 509.438px;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"height: 19.5938px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 19.5938px;\"\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 19.5938px;\"\u003e\u003ca href=\"\/products\/ld2410c-24ghz-human-presence-sensor\" title=\"LD2410C\"\u003eLD2410C\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 19.5938px;\"\u003eLD2410B-P\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 19.5938px;\"\u003e\u003cstrong\u003eLD2420\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.5938px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 19.5938px;\"\u003e\u003cstrong\u003eSupply voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 19.5938px;\"\u003e5V\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 19.5938px;\"\u003e5V\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 19.5938px;\"\u003e3.3V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.5938px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 19.5938px;\"\u003e\u003cstrong\u003eSignal levels\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 19.5938px;\"\u003e3.3V compatible\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 19.5938px;\"\u003e3.3V compatible\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 19.5938px;\"\u003e3.3V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.5938px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 19.5938px;\"\u003e\u003cstrong\u003eConfiguration\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 19.5938px;\"\u003eBluetooth or UART\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 19.5938px;\"\u003eBluetooth or UART\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 19.5938px;\"\u003eUART\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 58.7812px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 58.7812px;\"\u003e\u003cstrong\u003eReported target information\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 58.7812px;\"\u003eSeparate moving and stationary target data\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 58.7812px;\"\u003eSeparate moving and stationary target data\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 58.7812px;\"\u003ePresence, distance and radar energy data\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 58.7812px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 58.7812px;\"\u003e\u003cstrong\u003eDetection tuning\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 58.7812px;\"\u003eSeparate moving and stationary sensitivity for each distance gate\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 58.7812px;\"\u003eSeparate moving and stationary sensitivity for each distance gate\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 58.7812px;\"\u003ePer-gate trigger and hold thresholds with calibration support\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 58.7812px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 58.7812px;\"\u003e\u003cstrong\u003eTypical maximum range\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 58.7812px;\"\u003eApproximately 6m\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 58.7812px;\"\u003eApproximately 6m\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 58.7812px;\"\u003eUp to approximately 8m\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 58.7812px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 58.7812px;\"\u003e\u003cstrong\u003eArduino compatibility\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 58.7812px;\"\u003eEstablished LD2410 libraries\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 58.7812px;\"\u003eEstablished LD2410 libraries\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 58.7812px;\"\u003eUses a separate LD2420 protocol and software integration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.1875px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 39.1875px;\"\u003e\u003cstrong\u003eESPHome compatibility\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 39.1875px;\"\u003eESPHome LD2410 component\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 39.1875px;\"\u003eESPHome LD2410 component\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 39.1875px;\"\u003eSeparate ESPHome LD2420 component\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.1875px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 39.1875px;\"\u003e\u003cstrong\u003ePhysical format\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 39.1875px;\"\u003eCompact, breadboard-friendly PCB\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 39.1875px;\"\u003eLong, narrow PCB\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 39.1875px;\"\u003eCompact square PCB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.1875px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 39.1875px;\"\u003e\u003cstrong\u003eHeader options\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 39.1875px;\"\u003ePre-soldered header\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 39.1875px;\"\u003ePre-soldered or headerless variant\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 39.1875px;\"\u003ePre-soldered header\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 78.375px;\"\u003e\n\u003ctd style=\"width: 19.1657%; height: 78.375px;\"\u003e\u003cstrong\u003eBest suited to\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 26.2807%; height: 78.375px;\"\u003eGeneral prototyping, Bluetooth tuning and established software support\u003c\/td\u003e\n\u003ctd style=\"width: 25.558%; height: 78.375px;\"\u003eProjects needing a narrow PCB or direct integration without headers\u003c\/td\u003e\n\u003ctd style=\"width: 23.9955%; height: 78.375px;\"\u003eNative-3.3V projects and threshold-based calibration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eFeatures\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e24GHz FMCW radar presence sensing\u003c\/li\u003e\n\u003cli\u003eDetects movement, micro-movement and relatively stationary people\u003c\/li\u003e\n\u003cli\u003eDetection range of up to approximately 8m for moving targets\u003c\/li\u003e\n\u003cli\u003eClose-range detection from approximately 0.2m\u003c\/li\u003e\n\u003cli\u003eApproximate target distance and radar energy reporting\u003c\/li\u003e\n\u003cli\u003eConfigurable minimum and maximum detection distance\u003c\/li\u003e\n\u003cli\u003ePer-gate trigger and hold thresholds\u003c\/li\u003e\n\u003cli\u003eCalibration support for measuring background energy\u003c\/li\u003e\n\u003cli\u003eAdjustable presence timeout\u003c\/li\u003e\n\u003cli\u003eSimple digital occupied\/unoccupied output\u003c\/li\u003e\n\u003cli\u003eUART data and configuration interface\u003c\/li\u003e\n\u003cli\u003eDedicated ESPHome LD2420 integration\u003c\/li\u003e\n\u003cli\u003eNative 3.3V operation\u003c\/li\u003e\n\u003cli\u003ePre-soldered breadboard-compatible 2.54mm header\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSensor type\u003c\/td\u003e\n\u003ctd\u003e24GHz FMCW radar presence sensor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDetection\u003c\/td\u003e\n\u003ctd\u003eMovement, micro-movement and relatively stationary people\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDetection range\u003c\/td\u003e\n\u003ctd\u003eApproximately 0.2m to 8m, depending on target and installation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum moving-target distance\u003c\/td\u003e\n\u003ctd\u003eUp to approximately 8m\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum micro-movement distance\u003c\/td\u003e\n\u003ctd\u003eUp to approximately 6m\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDetection angle\u003c\/td\u003e\n\u003ctd\u003eApproximately ±60°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSupply voltage\u003c\/td\u003e\n\u003ctd\u003e3.0V to 3.6V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTypical supply voltage\u003c\/td\u003e\n\u003ctd\u003e3.3V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAverage operating current\u003c\/td\u003e\n\u003ctd\u003eApproximately 50mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterfaces\u003c\/td\u003e\n\u003ctd\u003eUART and digital presence output\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUART baud rate\u003c\/td\u003e\n\u003ctd\u003e115200 baud on the supplied v1.6.1 firmware\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLogic level\u003c\/td\u003e\n\u003ctd\u003e3.3V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBluetooth\u003c\/td\u003e\n\u003ctd\u003eNot supported\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePin spacing\u003c\/td\u003e\n\u003ctd\u003e2.54mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003eApproximately 20 × 20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtocol compatibility\u003c\/td\u003e\n\u003ctd\u003eLD2420-specific UART protocol\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFirmware\u003c\/td\u003e\n\u003ctd\u003ev1.6.1+\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eResources\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/esphome.io\/components\/sensor\/ld2420\/\" rel=\"noopener\" title=\"ESPHome LD2420 Sensor\" target=\"_blank\"\u003eLD2420 Sensor in ESPHome\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.alldatasheet.com\/datasheet-pdf\/pdf\/2247899\/HI-LINK\/HLK-LD2420.html\" rel=\"noopener\" title=\"LD2420 datasheet\" target=\"_blank\"\u003eLD2420 datasheet\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003ePinout\u003c\/h3\u003e\n\u003cp\u003eWe tested our initial batch of these sensors and they were running\u003cstrong\u003e firmware version 1.6.1 or greater\u003c\/strong\u003e (this matters for the pinout):\u003c\/p\u003e\n\u003ctable style=\"height: 90px;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"height: 18px;\"\u003e\n\u003ctd style=\"width: 8px; height: 18px;\"\u003e1\u003c\/td\u003e\n\u003ctd style=\"width: 34.6719px; height: 18px;\"\u003e\u003cstrong\u003e3V3\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 540.844px; height: 18px;\"\u003e3.3V power input. \u003cstrong\u003eDo not connect this module to a 5V supply.\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 18px;\"\u003e\n\u003ctd style=\"width: 8px; height: 18px;\"\u003e2\u003c\/td\u003e\n\u003ctd style=\"width: 34.6719px; height: 18px;\"\u003e\u003cstrong\u003eGND\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 540.844px; height: 18px;\"\u003eGround connection.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 18px;\"\u003e\n\u003ctd style=\"width: 8px; height: 18px;\"\u003e3\u003c\/td\u003e\n\u003ctd style=\"width: 34.6719px; height: 18px;\"\u003e\u003cstrong\u003eOT1\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 540.844px; height: 18px;\"\u003eTX\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 18px;\"\u003e\n\u003ctd style=\"width: 8px; height: 18px;\"\u003e4\u003c\/td\u003e\n\u003ctd style=\"width: 34.6719px; height: 18px;\"\u003e\u003cstrong\u003eRX\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 540.844px; height: 18px;\"\u003eRX\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 18px;\"\u003e\n\u003ctd style=\"width: 8px; height: 18px;\"\u003e5\u003c\/td\u003e\n\u003ctd style=\"width: 34.6719px; height: 18px;\"\u003e\u003cstrong\u003eOT2\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 540.844px; height: 18px;\"\u003eSecondary digital output. Function may vary with firmware and configuration.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003ePackage Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1x LD2420 24GHz Human Presence Sensor \u003cstrong\u003e(header pre-soldered)\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"The Pi Hut","offers":[{"title":"Default Title","offer_id":55974843122049,"sku":"106691","price":3.5,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0176\/3274\/files\/ld2420-24ghz-human-presence-sensor-the-pi-hut-106691-1250931780.jpg?v=1784911629","url":"https:\/\/thepihut.com\/products\/ld2420-24ghz-human-presence-sensor","provider":"The Pi Hut","version":"1.0","type":"link"}