How is this different from a PIR motion sensor?

It uses 24GHz radar to sense presence, including people who are still, and it works through plastic and in the dark. PIR only reacts to moving body heat and needs line of sight.

Can I connect it to a 5V Arduino?

The module runs on 3.3V and its serial and level outputs are 3.3V. Use a level shifter or a 3.3V board such as an ESP32 to avoid damage.

What comes in the box?

Three induction modules with pins pre-soldered. No cables, enclosure or power supply are included.

What is the detection range and angle?

0.75 to 6 m, adjustable, with a ±60° field of view. Range and sensitivity are set over the serial interface.

Does it work behind a wall or case?

Yes, 24GHz radar passes through plastic, glass and thin drywall, so it can sit inside an enclosure. Metal blocks it.

What output formats does it give?

Serial ASCII data at 3.3V, or a simple high/low level signal for presence.

Unbranded

24G MmWave LD2420 Human Presence Radar Sensor Motion Detection Module

Best price now

$10.91at WalmartChecked Nov 9

Prices are checked against each store and labelled with when.

Visit Walmart

Unbranded

24G MmWave LD2420 Human Presence Radar Sensor Motion Detection Module

Best price now

$10.91at WalmartChecked Nov 9

Prices are checked against each store and labelled with when.

Visit Walmart

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Price facts

Last seen at $10.91 at Walmart on Nov 9.

Our take on the 24G MmWave LD2420 Human Presence Radar Sensor Motion Detection Module

This is a bare 24GHz FMCW radar module built around the LD2420 chip. It detects human presence and motion from 0.75 to 6 m with a ±60° field, and outputs results over 3.3V serial as ASCII or as a simple high/low level. It suits makers and DIY smart-home builders who want presence detection that sees through plastic and glass and works in the dark, unlike a PIR sensor. It is a component, not a finished product: you supply power, wiring and firmware, and it ships as three modules with pins.

Best forMakers building presence-aware lighting or HVAC automationsESP32 and Arduino projects needing through-wall or in-dark detectionDIY room occupancy sensors for Home AssistantReplacing PIR where still-body detection matters

Pros

Detects stationary people, not just motion, unlike PIR
Sees through plastic, glass and thin walls
Works in darkness and is not fooled by heat or sunlight
Adjustable 0.75–6 m range and ±60° angle
Simple 3.3V serial ASCII or high/low output
Wide -40°C to +85°C operating range

Cons

Bare module: no enclosure, cable or documentation in the box
3.3V logic only; 5V microcontrollers need level shifting
~50mA draw is high for battery-powered builds
Radar can trigger on moving fans, curtains or pets
Setup and tuning require serial commands and firmware work

24G MmWave LD2420 Human Presence Radar Sensor Motion Detection Module prices at every store

WalmartNew
In stockSold by Zone Technology ShopReturns: Sold by a Walmart Marketplace seller; returns go to the seller under the seller's returns policy.
$10.91Free shippingChecked Nov 9
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What reviewers say

Feedback on LD2420-based boards is generally positive among makers, who value real still-presence detection over PIR. Complaints center on false triggers from moving objects and the effort of tuning sensitivity and range.

What people mention

Presence detectionPraisedOwners say it keeps detecting a person who is sitting still, where PIR sensors drop out.
False triggersCriticisedMoving fans, curtains and pets can set it off, so placement and threshold tuning matter.
SetupMixedWiring is simple, but configuring range and sensitivity over serial takes patience.
DocumentationCriticisedThe serial command set and pinout are thinly documented for beginners.
Power drawMixedAround 50mA is fine on mains but heavy for battery projects.

About the 24G MmWave LD2420 Human Presence Radar Sensor Motion Detection Module

This is a 24 GHz millimeter-wave radar module for human presence and motion detection. It uses FMCW modulation and operates in the 24G-24.25GHz band with a 250MHz sweep bandwidth.

Detection distance is adjustable from 0.75 to 6 m, with a detection angle of ±60°. The module outputs data as serial ASCII or as a high or low 3.3V level. It runs on 3.3V at about 50mA and works in ambient temperatures from -40°C to +85°C.

The body is made of plastic and metal, and the module comes with pins.

Frequency: 24G-24.25GHz
Modulation: FMCW
Sweep bandwidth: 250MHz
Detection distance: 0.75 to 6 m, adjustable
Detection angle: ±60°
Power supply: 3.3V (typ.)
Current: About 50mA
Output level: 3.3V serial level
Data format: Serial ASCII output, or high and low level 3.3V
Operating temperature: -40°C to +85°C
Material: Plastic and metal
Color: Blue
Pins: Default with pins
In the box: 3 x induction module

Specifications

color: BlueSource

Questions and answers

How is this different from a PIR motion sensor?: It uses 24GHz radar to sense presence, including people who are still, and it works through plastic and in the dark. PIR only reacts to moving body heat and needs line of sight.
Can I connect it to a 5V Arduino?: The module runs on 3.3V and its serial and level outputs are 3.3V. Use a level shifter or a 3.3V board such as an ESP32 to avoid damage.
What comes in the box?: Three induction modules with pins pre-soldered. No cables, enclosure or power supply are included.
What is the detection range and angle?: 0.75 to 6 m, adjustable, with a ±60° field of view. Range and sensitivity are set over the serial interface.
Does it work behind a wall or case?: Yes, 24GHz radar passes through plastic, glass and thin drywall, so it can sit inside an enclosure. Metal blocks it.
What output formats does it give?: Serial ASCII data at 3.3V, or a simple high/low level signal for presence.
Where is the 24G MmWave LD2420 Human Presence Radar Sensor Motion Detection Module cheapest?: At Walmart, for $10.91, as of our latest check.