ESP32 LD2450 Multi-Target Presence Sensor with Home Assistant

The LD2450 is one of the more interesting mmWave sensors for Home Assistant because it is not just a simple “occupied or not” radar. ESPHome describes it as a human presence, motion detection and tracking radar that can track the position of moving targets in real time, including distance, angle, and speed relative to the sensor. That makes it far more useful for directional room automations and multi-person spaces than the usual one-bit presence sensor.

Why the LD2450 is different

A lot of presence sensors are basically glorified yes/no detectors. They can be useful, but they do not really tell you where someone is.

The LD2450 is different because it is built for target tracking. ESPHome’s documentation says it can expose real-time measurements such as:

target distance
target angle
target speed
X and Y coordinates
per-target data
zone-based presence logic

That means you can do things like:

turn on desk lights only when somebody is near the desk
keep the sofa lamp on when someone is sitting on the sofa
ignore movement in a doorway while tracking the main seating area
build left/right or near/far automations in one room

That is the real appeal. It is not just presence. It is position-aware presence.

Why use an ESP32 with it

You use the LD2450 with an ESP32 because ESPHome already has an official ld2450 component. That matters a lot. It means you do not need old custom external components or weird hacks anymore. ESPHome added native LD2450 support in 2025.3.0, calling it “the long-awaited Ld2450,” and the official component is now the sensible starting point.

Using an ESP32 and ESPHome gives you:

direct Home Assistant integration
local processing
easy entity creation
configurable zones and settings
cleaner updates than custom integrations

Bluntly, now that the official component exists, there is very little reason to build a new LD2450 setup the hard way.

What you need

an ESP32 development board
an HLK-LD2450 radar module
jumper wires
a stable 5V or 3.3V-powered setup depending on your board and wiring design
Home Assistant
ESPHome

The important technical point from the ESPHome docs is that the LD2450 uses UART, and ESPHome strongly recommends using a hardware UART because the sensor’s default speed is 256000 baud. The docs also say parity must be NONE and stop_bits must be 1.

Before you start: firmware requirement

This bit matters.

ESPHome says the LD2450 should be running firmware V2.02.23090617 or later for proper integration functionality. If it is older, update it first using the vendor’s HLKRadarTool mobile app.

If you skip this and things behave strangely, do not immediately blame ESPHome. Sometimes the boring answer is the right one: outdated sensor firmware.

Wiring the LD2450 to the ESP32

The official docs focus on UART setup rather than giving one single mandatory pinout, so a typical practical approach is:

LD2450 TX → ESP32 RX
LD2450 RX → ESP32 TX
GND → GND
VCC → appropriate power rail for your module and board setup

Visual wiring diagram

The LD2450 uses a UART connection, so the wiring is simple once you remember the golden rule:

LD2450 TX goes to ESP32 RX
LD2450 RX goes to ESP32 TX

Wiring overview

HLK-LD2450 radar                ESP32
──────────────────────────      ─────────────────────
VCC   ───────────────────────▶  5V or 3V3*
GND   ───────────────────────▶  GND
TX    ───────────────────────▶  GPIO16 (RX)
RX    ───────────────────────▶  GPIO17 (TX)

* Use the correct supply voltage for your specific LD2450 board/module version and your wiring setup.

Pin-by-pin table

LD2450 pin	Connect to ESP32	Purpose
VCC	5V or 3V3	Power
GND	GND	Ground
TX	GPIO16 (RX)	Radar sends data to ESP32
RX	GPIO17 (TX)	ESP32 sends config data to radar

Recommended ESP32 UART pins

A common clean setup is:

GPIO17 as TX
GPIO16 as RX

That matches this ESPHome config:

uart:
  id: uart_ld2450
  tx_pin: GPIO17
  rx_pin: GPIO16
  baud_rate: 256000
  parity: NONE
  stop_bits: 1

Quick “don’t get it backwards” reminder

This is the part people mess up:

sensor TX → ESP32 RX
sensor RX → ESP32 TX

Not TX to TX.
Not RX to RX.

LD2450 wiring tip: The module uses high-speed UART at 256000 baud, so use a hardware UART on the ESP32, keep wiring short, and double-check that TX/RX are crossed correctly.

┌────────────────────┐         ┌────────────────────┐
│     HLK-LD2450     │         │       ESP32        │
├────────────────────┤         ├────────────────────┤
│ VCC                ├────────▶│ 5V / 3V3           │
│ GND                ├────────▶│ GND                │
│ TX                 ├────────▶│ GPIO16 (RX)        │
│ RX                 ◀─────────┤ GPIO17 (TX)        │
└────────────────────┘         └────────────────────┘

A common example on ESP32 dev boards is to use a secondary hardware UART, such as GPIO16 and GPIO17, but the exact pins depend on your board. The part that matters is using a real hardware UART that supports the required baud rate reliably. That recommendation comes directly from the ESPHome docs.

What the LD2450 is good at

The LD2450 is mainly for indoor human target tracking. ESPHome describes the module as part of Hi-Link’s 24 GHz millimeter-wave radar series and says it is primarily intended indoors for location tracking of moving human targets.

So it is well suited to places like:

home offices
living rooms
kitchens
hallways
open-plan rooms
bed positioning or desk positioning projects

It is less appealing if all you want is the simplest possible occupancy sensor for a tiny room. In that case, a simpler LD2410-type setup is often enough. The LD2450 makes more sense when you actually care about where the person is.

Example ESPHome YAML

Here is a clean starting example for an ESP32 with the LD2450 on a hardware UART.

esphome:
  name: ld2450-presence
  friendly_name: LD2450 Presence

esp32:
  board: esp32dev
  framework:
    type: arduino

logger:

api:

ota:

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

uart:
  id: uart_ld2450
  tx_pin: GPIO17
  rx_pin: GPIO16
  baud_rate: 256000
  parity: NONE
  stop_bits: 1

ld2450:
  uart_id: uart_ld2450

binary_sensor:
  - platform: ld2450
    has_target:
      name: "LD2450 Has Target"
    has_moving_target:
      name: "LD2450 Has Moving Target"
    has_still_target:
      name: "LD2450 Has Still Target"

sensor:
  - platform: ld2450
    target_count:
      name: "LD2450 Target Count"

    target_1:
      x:
        name: "Target 1 X"
      y:
        name: "Target 1 Y"
      speed:
        name: "Target 1 Speed"
      angle:
        name: "Target 1 Angle"
      distance:
        name: "Target 1 Distance"

    target_2:
      x:
        name: "Target 2 X"
      y:
        name: "Target 2 Y"
      speed:
        name: "Target 2 Speed"
      angle:
        name: "Target 2 Angle"
      distance:
        name: "Target 2 Distance"

    target_3:
      x:
        name: "Target 3 X"
      y:
        name: "Target 3 Y"
      speed:
        name: "Target 3 Speed"
      angle:
        name: "Target 3 Angle"
      distance:
        name: "Target 3 Distance"

ESPHome’s official docs confirm the component supports target tracking metrics like distance, angle, speed, and coordinates, and the API docs also show direction-related enums such as approaching, moving away, and stationary.

What entities you actually get

The exact entity list depends on your YAML, but the official component is designed to expose much more than a single occupancy state. In practice, useful entities include:

overall target present
moving target present
still target present
target count
per-target X/Y position
per-target distance
per-target angle
per-target speed

That is what makes the LD2450 worth the extra effort. With simpler sensors, you get presence. With the LD2450, you get presence plus spatial context.

Zones are where this gets interesting

The raw target coordinates are useful, but zones are what turn the sensor into something genuinely practical.

Instead of asking “is there someone in the room,” you can ask:

is someone in the desk zone
is someone in the sofa zone
is someone near the TV wall
is someone in the doorway but not actually in the room

The ESPHome component and underlying API docs include zone support, and the community discussion around LD2450 products and setups has also focused heavily on area detection and exclusion areas because that is the feature that makes multi-target radar feel smarter than basic PIR or basic occupancy.

For real homes, zones are the whole point.

Good Home Assistant use cases

Desk lighting

Turn on task lighting only when someone is sitting near the desk, not just whenever the room has movement.

Sofa presence

Keep ambient lighting and media automations active only when someone is actually in the sofa area.

Hallway filtering

Ignore traffic passing through a doorway so lights in the main room do not keep changing unnecessarily.

Dual-purpose room logic

In an office/guest room or kitchen/dining room, use different automations based on which zone is occupied.

That is where the LD2450 earns its keep. Otherwise, you are paying for richer tracking data and then throwing it away.

Placement matters more than people admit

All mmWave sensors are sensitive to placement, but multi-target tracking makes this even more obvious.

A few practical rules:

mount it where it can see the useful part of the room
avoid pointing it straight through busy walk-through paths unless that is your goal
think about the coordinate system before defining zones
test with real people standing and sitting where they actually use the room
do not expect one sensor to understand your room layout automatically

The official docs emphasize the LD2450 as an indoor human target tracker, not a magic room-awareness box. You still need to place it sensibly and tune it.

LD2450 vs simpler presence sensors

The easiest way to think about it:

PIR: cheap, simple, motion only
basic mmWave: presence, sometimes stillness detection, but not much location awareness
LD2450: target tracking with coordinates and multiple targets

So the LD2450 is not automatically the best choice for every room. It is the better choice when:

you want zones
you want multi-person tracking
you want directional automations
you want to distinguish one side of a room from another

If you only need “turn bathroom light on when someone enters,” it is probably overkill.

Common problems

No data or flaky data

The first things to check are the boring ones:

firmware version on the LD2450
UART pin mapping
hardware UART usage
baud rate set to 256000
parity and stop bits matching the official requirements

Those requirements come directly from the ESPHome docs.

Entities appear but automations feel weird

That usually means one of these:

poor sensor placement
zones not tuned properly
you are using raw target data when a binary zone entity would be better
the room is too busy for your current logic

Target tracking works but does not feel useful

That usually means you have not turned coordinates into actual room logic yet. Raw X/Y numbers look clever in dashboards, but zones and practical automations are what make the setup worth having.

A practical automation idea

A good starting pattern is:

use has_target as broad occupancy
use a zone or target coordinates for the main action
add a short delay before clearing presence
keep the automation simple at first

For example:

if desk zone occupied → turn on desk lamp
if sofa zone occupied → turn on warm ambient light
if only doorway area triggered → ignore

That is much better than trying to use every possible entity from day one.

Final thoughts

The ESP32 LD2450 combination is one of the more advanced and useful Home Assistant presence projects because it gives you something most cheap sensors do not: real target tracking. The official ESPHome component now makes it much easier to build than it used to be, as long as you respect the UART requirements and firmware version requirements.

The blunt summary is this: if you want simple occupancy, buy something simpler. If you want position-aware presence with multiple targets, the LD2450 is where things start getting genuinely interesting.