SmartHomeShop Docs

Radar and Sensor Modules

The CeilSense V2 base has no radar and no SCD41. You decide what the device measures by adding modules. This page helps you choose, explains what can and cannot be combined and covers fitting.

What You Get Without a Module

Function Available
Light, air pressure, LED ring, buzzer, network Always, in the base
Presence, position, zones Only with a radar configuration
CO2, temperature, humidity Only with the SCD41 module

Without a radar the device measures no presence. Without the SCD41 it measures no CO2, temperature or humidity. BMP388 Temperature is the temperature inside the device and does not replace room temperature.

Which Radar Should You Choose?

Choose one configuration. All are Hi-Link mmWave radars without a camera.

What you want Choose
To know reliably whether someone is there, also sitting still, and see where up to 3 people are LD2412 + LD2450
To track up to 5 people with a single module LD2460
To draw polygon zones in the Room Designer with the current firmware LD2460
To measure height as well as X and Y, with areas in 3D LD6002B (firmware not finished yet)

Comparison

LD2412 + LD2450 LD2460 LD6002B
Modules 2 1 1
Frequency 24 GHz 24 GHz 60 GHz
Presence, also sitting still Yes Yes Yes
People tracked Up to 3 Up to 5 (3 of them still) Up to 3
Coordinates X/Y X/Y X/Y/Z
Field of view ±75° (LD2412); ±60° × ±35° (LD2450) 120° × 90° ±60° × ±60°
Range, slant 9 m presence, 6 m tracking 6 m moving, 5 m still 3 m typical, max. 6 m
Zones 3 rectangles in the radar. Polygons in the Room Designer will follow with release firmware. Polygons in the Room Designer 4 detection areas and 4 interference areas in 3D
ESPHome Native SmartHomeShop component Native since ESPHome 2026.8

What Each Radar Sees

LD2412

Sees whether someone is there, even with micro-movements like breathing. It tells moving and still apart and gives distance and signal energy, but no X/Y position.

LD2450

Tracks up to 3 people with X and Y coordinates, speed and direction. It has 3 rectangular zones in the radar itself. Together with the LD2412 it gives you reliable presence and position.

LD2460

Tracks up to 5 people with X and Y coordinates, of which 3 can be still. It uses a single module with a wide 120° × 90° field of view. The LD2460 does not tell moving and still targets apart, so it has no separate moving or still entities. The firmware runs it in top installation mode for ceiling mounting.

Mirrors, metal wardrobes, windows and other large reflective surfaces can create a second target or shift a position. See Calibration.

LD6002B

A 60 GHz radar that measures X, Y and height of up to 3 people. It has 4 detection areas and 4 interference areas in 3D, and the firmware runs it in top installation mode. Firmware for the LD6002B on CeilSense V2 is not finished yet.

Coverage on the Floor

Module range is not floor coverage. Ceiling height, mounting, obstacles and settings decide coverage. At a 2.7 m ceiling, count on this ground radius:

Radar Movement Sitting still
LD2412 or LD2460 About 4 m About 3 m
LD6002B About 3 m all around About 3 m all around

These figures use 80 percent of the manufacturer's slant figures for ceiling mounting, limited per axis by the field of view. That is why they are lower than the module range in the comparison table. Tracking coverage is not a perfect circle: it is narrower along the axis with the smaller field of view.

Place the sensor centrally in the room.

What Cannot Be Combined

LD2412 + LD2450 is the only two-radar combination.

  • Never fit the LD2460 and the LD2412 at the same time.
  • Never combine the LD6002B with the LD2412 or the LD2460.

These modules share the same connection. Every other pair is not supported either.

The firmware has to match the modules in the device, so changing the radar configuration also means changing the firmware. See Firmware.

Fitting Modules

You receive the modules loose for self-assembly, or you choose the assembly service when you order: we fit the selected radar and SCD41 in the device for a supplement per device. Ceiling mounting and electrical installation are not included.

Disconnect all power first. Unplug USB-C and Ethernet. If the sensor is on mains, switch the circuit off and leave disconnecting it to a qualified installer.

Self-assembly in general steps:

  1. Disconnect all power.
  2. Work on a clean, dry surface and take care with static electricity: touch a grounded object before you pick up a module, and hold it by the edges.
  3. Open the device (the cap on the room side) as described in the guide that comes with the release.
  4. Fit the module in its matching socket with the correct orientation. Do not force the pins.
  5. Check that the module sits firmly. A radar can miss someone when the module was not fitted firmly.
  6. Close the device and reconnect the power.
  7. Check in Home Assistant that the module is seen: LD2412 Firmware Version, LD2450 Firmware Version or Tracking Radar Firmware should show a value.

Step-by-step photos follow at release.

SCD41 Module

The Sensirion SCD41 is a separate module for CO2, temperature and humidity. These three readings are not available without it.

  • CO2: specified range 400 to 5,000 ppm, output up to 40,000 ppm, accuracy ±(50 ppm + 2.5% of reading) between 400 and 1,000 ppm
  • Temperature: -10 to +60 °C
  • Humidity: 0 to 95 %RH, non-condensing
  • New values every 30 seconds

Recessed mounting and heat from electronics influence the temperature reading, so use temperature mainly for trends. See Calibration.

Fit it the same way as a radar module. The firmware has to include SCD41 support: without it the entities do not appear.