This week’s EYE ON NPI (video) is *PIRfect* for adding human-motion detection to your product or project – it’s Panasonic’s new PaPIR sensor line-up, featuring ultra-low power current consumption, a jaunty square shape, and multiple color options so your sensors will be detecting in style.
PIR sensors are great for detection motion of humans and other large & warm things. They are particularly excellent for making your designs use less power / be more ‘green’ because you can detect when a person walks into the room or in front of your control panel: so monitors or lights can be disabled or dimmed when there’s no people around. Or your thermostat will know that it doesn’t need to turn on the AC or heat since nobody is at home. And it does this all without video cameras, face detection or cloud computing (we’re only being slightly sarcastic here!)
The PIR sensor element itself has two or more slots in it, each slot is made of a special material that is sensitive to IR. The two slots can ‘see’ out past some distance (basically the sensitivity of the sensor). When the sensor is idle, both slots detect the same amount of IR, the ambient amount radiated from the room or walls or outdoors. When a warm body like a human or animal passes by, it first intercepts one half of the PIR sensor, which causes a positive differential change between the two halves. When the warm body leaves the sensing area, the reverse happens, whereby the sensor generates a negative differential change. These change pulses are what is detected.
The Panasonic PaPIR modules take a full circuit board’s worth of PIR support components and tuck them all into the metal can that fits beneath the plastic lens of the sensor. Since it is fully integrated, you only need to solder in 3 wires: power, ground and output for instant detection up to 5 meters away.
There are other PIR sensors available, but they tend to be kind of large and are hard to integrate into a design directly. They’re best for maker projects, not necessarily products. The EKMB/EKMC designs from Panasonic brings a very compact and ultra-low power solution for when you want a small 5 meter-range PIR sensor that can be soldered directly to a board. And the power draw is super low: about 1~20uA, so it can be used for battery powered products.
Since it’s so low power, you could connect the output pin directly to an enable pin for a power supply or to a transistor for turning on power to lights or a buzzer. Note that the ambient current draw will affect the stability warm-up time and the sensitivity, so you’ll probably want to try different ones in-situ to see the minimal current draw you can get away with.
*PIRhaps* you’re interested in picking some up? Well, today is your day cause Digi-Key has all the different sizes, colors and sensitivity options available for purchase right now in stock! Visit the Panasonic EKMB/EKMC Series Flat Square Lens Type PIR Motion Sensors feature page to place your order today and you will be able to add ultra-low-power sensing by tomorrow afternoon.
See on Digi-Key at https://www.digikey.com/short/zt5bvw2j