I am using the Aeon-Labs 4-in-1 multi-sensor, USB-powered full-time, with a Vera 2. I conducted some motion sensing tests today in bright daylight while adjusting the pot on the back for sensitivity. It’s now at its midpoint. I can trigger it by walking in its path up to about 25 feet away.
I tried the same tests tonight in full darkness, including driving my car with its lights on right by it, and it didn’t trigger. I finally had to walk up to within 4 feet of it and wave my hand at it to trigger it. 
I thought it detected motion regardless of light level?
Chris Cheng with Aeon-Labs replied to my question with the following answer:
I suggest tuning the Multisensor sensitivity for night time instead if it is of more priority. The Multisensor should be able to detect movement at night, but this may require to have the sensitivity much higher.
What I’ve seen is that if I calibrate it in the daytime for minimal false triggers by turning down the sensitivity it won’t trigger at night unless I wave my hand right in front of it. If I crank up its sensitivity for night use it’ll trigger frequently. I have tried the sensitivity dial at half-way and it false triggers during the day but barely responds at night. Next up: increase sensitivity until it triggers at night and disarm it during the day (because who needs a porch light on during the day?).
The physics on these devices is amazing, but they are using InfraRed spectrum, of which the sun radiates quite nicely.
More IR light bouncing around creates a much better state for which to detect changes. Lower overall IR, lower response.
Your car’s lights won’t affect it too much as they really don’t radiate much IR.
On that note, you could try to add to your presence settings to look for a swift change in light, as in your car coming up the driveway. Another possible trigger to capture what you are looking for.
On that note, you could try to add to your presence settings to look for a swift change in light, as in your car coming up the driveway. Another possible trigger to capture what you are looking for.[/quote]
Thank you for the insights, Bulldoglowell! What and where are “presence settings”? I noticed in another recent thread you use the HomeSeer HSM100-S3 Z-Wave Multi Sensor outdoors. Does it exhibit the same day vs night behavior?
An example would be detecting a car, using the dramatic change in light when it approaches. You can use the light sensor component in your multisensor to aid in capturing the presence of a car in the driveway.
More options, more likely to detect.
I’ll continue the conversation here.
[quote=“Bulldoglowell, post:5, topic:180965”]An example would be detecting a car, using the dramatic change in light when it approaches. You can use the light sensor component in your multisensor to aid in capturing the presence of a car in the driveway.
More options, more likely to detect.
I’ll continue the conversation here.[/quote]
Interesting idea! But my impression of the Aeotec’s illumination sensor is that it can only push data or have its data be pulled at programmed time intervals; it isn’t “triggered” by external events like the motion sensor. So short of polling it constantly how could you use it to detect a car’s lights?
If you have power to it, set it to frequently transmit updates on the light sensor, if you want to try it.