Thanks for your review! I have a number of Aqara FP2’s and FP300. I just got an FP400 this weekend and am very pleased with it. I use both HomeKit and Home Assistant, and one target I strive for is for HomeKit not to be dependent on Home Assistant, and vice-versa. Yeah, I know I can add devices to Home Assistant and expose it from HA to HomeKit, but I prefer that they are not dependent on each other. This was a challenge with FP2. I added my FP2 to HomeKit, but in order for Home Assistant to see the FP2, I had to use the Presence Soft Sensor feature (see What is the Presence Soft Sensor and how to set it up for better automations?) , so HA can see the presence info (plus, the feature allows other devices such as door sensors to weigh in on presence, although for mmWave sensors, door sensors in my experience aren’t that important).
Anyway, I really do like the Zigbee & Matter support of the FP400. I added my FP400 to my Aqara M3 hub via Zigbee. The zones were automatically exported via Matter from the M3 hub to both Home Assistant and HomeKit, which allows HomeKit and HA to be independent of each other.
One tip for Home Assistant users: eachl Aqara zone is exported to HA as a device. In addition to the room-level device (containing occupancy and luminance info), f you have multiple zones defined in Aqara, you will wind up with multiple devices - one HA device per Aqara zone. All the HA devices are named “Spatial Multi-Sensor FP400”, with entities that belong to it for Occupancy, sensitivity, hold time, etc. I renamed my HA devices to be the name of the zones I created in the Aqara app, and then recreated the entity id. Likewise, the M3 exports, via Matter, the Aqara zones to HomeKit, and also calls the Occupancy sensors in HomeKit “Spatial Multi-Sensor FP400”, and I renamed them to match the Aqara zone names.
It would have been nice if the device names were already named after the names used in the Aqara app. I had to go to each zone and then based on its occupancy, rename the devices in HA and HomeKit.
I really wish that posture was supported. I use my FP400 in my Home Theater room. Normally, I want all lights to be off when watching a movie since I use a projector). So, it would have been easy to turn on/off lights depending on if anyone is or is not standing. Without posture detection, I had to create zones for seating and for the floor, and if someone enters the floor zone, then turn on the path lights. But it’s a bit tricky doing this since the floor area is also covered by legs when seats are reclined and leg rests go up.
Overall, I’ve been using the FP400 for 2 days, and it has worked very well for me. I have not gotten ghost/phantom issues yet. Like the FP2, placement is critical. At least with the FP2, fine tuning the placement, even tilt of the sensor, helps minimize or even eliminate ghosting issues. I believe FP400 is supposed to be even less prone to ghosting than the FP2, but placemenbtn is still important. I’ve only used FP2 for 2 days, but so far, I like it. I don’t plan on replacing my FP2s yet, but the FP400 will be my go-to sensor for other rooms (as long as a plug is conveniently located and I need multi-zone support; otherwise FP300 is what I use).
EDIT: I wanted to add - if you were to add a new zone in the Aqara app, the existing zones in Home Assistant are unaffected. Only the new zone is added. However, if you add a new zone in the Aqara app, all the old zones will be deleted from HomeKit and all zones will be resent from the M3 hub to HomeKit.