I can't find any details about how much power you can get with this. Let's try a back of the envelope calculation.
My WiFi router has probably 2W. If you put this device at 1m (3') and assume that the power is evenly distributed you get 2W/(4 pi 1m^2) = 0.16 W/m^2. Let's assume that the surface of this device is 10cmx10cm (4''x4'') (quite big for a small device) and it's perfectly perpendicular, you get 0.16 W/m^2 x (.1m x .1m) = 0.0016W = 1.6 mW (and this calculation is quite optimistic, because it assumes no loss in the transmission and in the conversion or storage)
A typical LED has 30 mW (or more), so this is not enough to keep it light. Perhaps blink it once every 20 seconds.
And if the device is further away, it's worst. The calculation assumes that the distance is 1m (3'), with 2m (7') the power is reduced x4.
In the web page they show a fire detection device with a nice led that, so I'm not sure that they can collect enough power to blink the led. The surveillance camera is completely out of discussion, specially if it has a motor.
My WiFi router has probably 2W. If you put this device at 1m (3') and assume that the power is evenly distributed you get 2W/(4 pi 1m^2) = 0.16 W/m^2. Let's assume that the surface of this device is 10cmx10cm (4''x4'') (quite big for a small device) and it's perfectly perpendicular, you get 0.16 W/m^2 x (.1m x .1m) = 0.0016W = 1.6 mW (and this calculation is quite optimistic, because it assumes no loss in the transmission and in the conversion or storage)
A typical LED has 30 mW (or more), so this is not enough to keep it light. Perhaps blink it once every 20 seconds.
And if the device is further away, it's worst. The calculation assumes that the distance is 1m (3'), with 2m (7') the power is reduced x4.
In the web page they show a fire detection device with a nice led that, so I'm not sure that they can collect enough power to blink the led. The surveillance camera is completely out of discussion, specially if it has a motor.