After a brief experiment, I’ve gone all in on home automation, mainly using Aqara products. I have 17 FP300s around the house and I’m using it all through Zigbee2MQTT and Home Assistant. All the sensors are on firmware 6542. Generally it’s working well, but most of the problems I have seem to do with false or spurious readings from presence sensors and the most unreliable are in the two rooms where I have two sensors. In both cases the sensors are positioned on either side of a pillar, pointing away from each other. One room uses two sensors just because of the length of the room and they are treated as the same. If either of them shows presence then there is presence in the room. The other room has two seating areas and the lighting for each area is controlled by the sensor in that half.
Are there any guidelines as to how these should be configured or set up, for sensitivity, distance zones, spatial AI, etc. so as to avoid crosstalk between the presence radars of each sensor in the room.
If you use Zigbee mode, you are able to configure max range of the FP300. Open the device page, click three dots → On-Site Configuration → Detection Range.
The app will also show you how far is currently detected presence to help you set the distance properly. Setting this on both FP300s will help with separation of those two areas.
But unfortunately I can’t help with how to prevent interference. My FP300 regularly thinks there is someone when I open the window (I think the air from outside has dust and mmWave sensor just assumes it’s a person). Or when I turn on the oven, the heat triggers the PIR sensor. It needs about 20-30 minutes and then it corrects itself. I haven’t been able to fix this problem, I just live with it, because the sensor automates the LED strip, which is not too bright
Multiple FP2s in the same space generally won't interfere if not directly facing each other, allowing simultaneous operation in various modes.
That said, based on my own testing, I’ve had consistently worse results when using two mmWave sensors to cover the same room. I can’t say for certain that RF interference is the cause, but whatever the reason, I’ve found a single well-positioned sensor to be more reliable and predictable than trying to overlap coverage with two sensors.
So I’d definitely experiment with placement and orientation before assuming that adding a second sensor will improve coverage.
For one of the rooms (kitchen) I am experimenting with the “busy” end being PIR-only and the other end (with seating) using mmwave. That way the room should avoid radar conflicts.
The other room has two distinct seating areas with lighting, so needs two presence sensors with separate automations. Currently these two sensors are close together, but pointing away from each other, either side of a corner pillar. I’m am now worried about a radar “back-beam”. I wonder if things would improve if I move one sensor to another corner, still pointing away. The optimum positioning may take me some time.