Aqara FP400 Review: Spatial Multi-Sensor with Comprehensive Person Detection

Using the relatively new mmWave radar technology, the Aqara FP400 sensor is designed to operate without physical contact, as demonstrated in our test. At the same time, the model aims to impress with its wide coverage area and is even said to be capable of detecting up to 10 people in a room. We took a close look at the Spatial Multi-Sensor and reveal whether the manufacturer’s promises actually hold up.

Package Contents at a Glance

The contents of the Aqara FP400 Sensor package are remarkably compact: In addition to the device itself, the package includes a wall mount with screws and anchors, as well as a double-sided adhesive mount. Also included are a Quick Starter Guide and a USB-C to USB-C cable, which ensures a power supply.

The cable itself is two meters long and should therefore be suitable for most installation locations without any issues. If you need a longer cable, you can use any standard USB-C cable.

However, an Aqara Hub is not included, though it is required for use. For our Aqara FP400 review, we used the Aqara Hub M100. It works with all popular AI assistants such as Google Home, Alexa, and Apple Home.

Technical Details

Product	Aqara FP400
Dimensions	64 x 64 x 29.5 mm
Connection Type	USB-C, Bluetooth
Wireless Protocols	Zigbee, Thread
Field of view	120°
Operating temperature	-10 °C to 50 °C
Protection rating	IPX5
Relative humidity	0 to 95%
Product colors	White
Price (MSRP)	€79.99*

Aqara FP400 Review: Design & Build Quality

Visually, the sensor is quite appealing, as its white color and round design ensure that it blends seamlessly into a wide variety of settings. The only downside is that it requires a constant power connection via a cable, which noticeably disrupts the elegant design.

That said, there are no criticisms to be made regarding the build quality. The product also feels good to the touch, although it’s unlikely to be handled much once it’s installed.

Another highlight is the built-in hinge, which is mounted between the wall mount and the sensor and ensures optimal alignment. It provides enough resistance to hold the sensor in the desired position with millimeter precision, yet can be adjusted with minimal effort.

The only button on the underside is easy to reach but requires a bit more pressure to activate. This isn’t a major issue, however, since it’s only used to turn the sensor on and off. Once turned on, the sensor can do its job thanks to its power connection.

Setup & Installation: A Hub Is Required

An Aqara hub is required to receive the data transmitted by the sensor and integrate it with your smart home system. Before hanging the Aqara FP400 in place, you should first set up the hub and the free Aqara Home app.

Integrating the sensor into the app takes just a few seconds thanks to the corresponding QR codes located directly on the device and in the user manual. To do this, the sensor must first be connected to a power source via a cable before the corresponding QR code is scanned using a smartphone or tablet. Bluetooth then enables a connection to the app and directly to the Aqara Hub.

When mounting the sensor on a wall or ceiling, it’s best to follow the corresponding steps in the app. These steps clearly explain how and where to mount the sensor and what details (height, orientation, exact location on the wall or ceiling) to pay attention to.

In my test, I chose to mount the sensor using the magnetic disc: drill a hole in the wall, insert a wall plug, and secure the disc with a screw. After that, I was able to attach the sensor’s magnetic back to the metal disc. Finally, all that’s left is to make the appropriate adjustments in the app.

Zigbee & Thread: Choosing the Right Network Technology

During setup, users must decide whether they want to use Thread or Zigbee as the device protocol. The former is a networking technology developed specifically for devices in smart home systems. In plain language, this means: If you want to connect the Aqara FP400 sensor to your own smart home ecosystem—such as Apple Home, Alexa, Google Home, or Home Assistant—you should use this protocol.

Zigbee is a similar protocol, but it’s supported by other smart home networks. In addition to Aqara itself, these include Signify (Philips Hue), the IKEA Home Smart System, FRITZ! Smart Home, as well as Samsung SmartThings and Amazon Alexa (via compatible Zigbee hub systems).

So if you want to use the native features of the Aqara app or even own a compatible Aqara smart home system, you should definitely choose Zigbee. The manufacturer even points out that the widest range of features is only available when using the native Aqara smart home system.

For our test with Google Home, however, we opted for Thread. The installation took about ten minutes, as the necessary firmware had to be downloaded via the Aqara app and then transferred to the FP400 sensor via Bluetooth. Every time you switch from Zigbee to Thread (and vice versa), this software must be transferred again.

After that, there’s a brief setup process—which takes only about a minute—before you can start using the device. Finally, there was another quick setup via the Google Home app, which also took about a minute. After that, I was able to set up my first automations right away.

Aqara FP400 in a Real-World Test

To be fair, we’d like to point out that there were some initial issues integrating the Aqara FP400 into Google Home and using its associated features. A software update has since apparently resolved the problem, as all features were available to us afterward.

In the office, the Aqara FP400 now ensures, for example, that the music being played automatically pauses when no people are detected in the room. When a person is detected again, the music resumes. In addition, the lights turn on automatically as soon as the lux level—which is also measured by the sensor—drops below a certain threshold—but only if there’s actually someone in the room.

Zone detection also works really well; thanks to 60-GHz mmWave radar, it’s surprisingly precise. This allows you to set up specific zones within a room and assign separate automations to them. For example: If I’m in the armchair zone for at least 15 seconds, the reading light turns on automatically when the lux level falls below a certain threshold. If the two of us are in the game table zone, the board game playlist starts via Spotify and the lights at the table turn on.

As with any smart home system, the same applies here: the possibilities of the Aqara FP400 are limited only by your imagination. In principle, it’s also possible to turn on the heat as soon as people are detected in the room. Or to automatically close or open the blinds in the bedroom as soon as people are detected at a specific time and the lux levels exceed or fall below a certain threshold.

Privacy: No Camera or Microphone Required

We’d also like to mention a brief positive point: Since the Aqara FP400 uses radar technology, the device can operate entirely without cameras or a microphone. This offers a major advantage, particularly in terms of privacy, since no faces need to be stored and no conversations need to be recorded.

However, it’s important to note that while there is no directly personally identifiable information, radio waves are used to detect whether people are present in the relevant rooms. This data may then be stored in the cloud, which could potentially reveal patterns. So anyone who is particularly cautious about such data should carefully check in advance exactly what data is being stored here, how, and where.

Aqara FP400 Review: Our Conclusion

The Aqara FP400 sensor is best described as a practical addition to existing smart-home systems. For those who already own smart devices and want to control them via automations, this sensor offers an elegant and practical solution. The person detection works really well and, thanks to 60-GHz mmWave radar, can perform its task without any issues even in dark rooms.

However, those who value having as few visible cables as possible may be disappointed by the constantly visible power connection. An integrated battery might have been helpful here, but that’s really just nitpicking. It’s also a bit more expensive than traditional motion sensors and even pricier than the Aqara P100 (see our review). Otherwise, though, we’re absolutely impressed by the Aqara FP400 sensor’s features, accuracy, and low rate of false alarms.