Radar and Sensor Modules
CeilSense Pro has sockets for all radar options, and you choose one of three configurations. This page explains those configurations, what cannot be combined and which air sensors are built in. Which configuration ships as standard is announced at release.
Planned behavior. The firmware for CeilSense Pro is not written yet. Where this page describes what the firmware does, that is the plan and it can still change at release.
What Is Built In
| Function | Where it comes from |
|---|---|
| Light, air pressure, CO2, temperature, humidity, VOC and NOx | Built-in sensors |
| Optical smoke sensing (experimental) | Built in |
| LED ring, buzzer, speaker, microphone, network | Built in |
| Presence, position, zones | The radar configuration |
The climate sensors are part of the device, so there is no SCD41 module to add. Presence, position and zones always need a radar.
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 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 will run 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 will run it in top installation mode. Firmware for the LD6002B on CeilSense Pro 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 a Radar
How a radar is fitted or changed in CeilSense Pro is described in the guide that comes with the release. Step-by-step photos follow at release.
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.
Afterwards, check in Home Assistant that the module is seen: LD2412 Firmware Version, LD2450 Firmware Version or Tracking Radar Firmware should show a value.
Built-In Air Sensors
The Pro has four sensors for the air in the room. Which one you use depends on what you want to know.
| You want to know | Use | Planned entities | Good to know |
|---|---|---|---|
| How stale the air is, for ventilation | SCD41 | SCD41 CO2 |
CO2 in ppm, new value every 30 seconds |
| Room temperature and humidity | SHT45 | Follow with release firmware | The dedicated sensor for temperature and humidity |
| Temperature and humidity from the CO2 sensor | SCD41 | SCD41 Temperature, SCD41 Humidity |
A second source. Use it mainly for trends. |
| Whether the air is changing, for example from cooking, cleaning products, poor ventilation or outdoor pollution | SGP41 | SGP41 VOC Index, SGP41 NOx Index |
Indices, not ppm. Look at trends, not single values. |
| Air pressure | BMP388 | BMP388 Pressure |
Also planned as pressure compensation for the SCD41 |
BMP388 Temperature is the temperature inside the device and does not replace room temperature. Recessed mounting and heat from electronics influence the temperature reading, so use temperature mainly for trends. See Calibration.
SCD41
- 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
Automatic self-calibration is planned to be off on the Pro, unlike on V2. See Calibration.
SHT45
A dedicated sensor for temperature and humidity. The prototype firmware has no SHT45 entities yet, so their names follow with release firmware.
SGP41
Measures VOC and NOx and reports both as an index from 1 to 500, not as ppm. Give it several hours of normal operation after a start or a move before you judge the readings.
BMP388
Measures air pressure, 300 to 1,100 hPa.