Product of the week: PIR Motion Sensor
In this episode of "Product of the Week," everybody's favorite Gadget Guru Robin Mitchell introduces the PIR Motion Sensor from Adafruit. The PIR Sensor, manufactured by Adafruit, is a small IR sensor that is located inside a special dome that enables for detection of IR signals in all directions. This module doesn’t react to the presence of IR signals, but instead, the changes in IR signal, making it perfect for motion detection.
Why is the PIR (Motion) Sensor awesome?
What makes the PIR (Motion) Sensor awesome is that it is highly sensitive to motion, and is capable of sensing in all directions. This means that you don’t need a bazillion sensors around the room trying to capture motion. Another sweet feature of the PIR (Motion) Sensor is that it uses a single logic output that indicates if motion has been detected or not, thus really simplifying motion detection systems.
Features and specs of the PIR (Motion) Sensor
To start, the PIR (Motion) Sensor is capable of detecting people up to 7 meters away (for those living in the uncivilized areas of the world, that’s about 20 feet). While the datasheet does specify that it may be able to work on zombies, this isn't guaranteed as only objects that are hot will trigger the sensor, so if you have zombies from 7 days to die or The Waking Dead, good luck trying to pick them up with this sensor. Personally, I would recommend either a sound sensor or laser fence for such zombies. The plastic dome over the sensor provides a field of view of 120 degrees, which is substantial for motion detection.
The PIR (Motion) Sensor operates from a wide range of different input voltages from 5V to 12V, which makes using this module extremely easy (no need for power regulators). The digital output of this module is a single wire whose digital levels are 0V and 3.3V, and an adjustable onboard delay can adjust the time it takes for a signal to be generated after detecting an object.
To help with installation, a 30cm cable is provided, which gives you some freedom with mounting the sensor. As such, your controller can be mounted in a different location to the PIR module, such as in a floorboard, ceiling, or wall.
What projects can you do with the PIR (Motion) Sensor?
Primarily, this module will be used for motion detection of warm bodies, such as people and animals. As such, the first, and most common use, for the PIR (Motion) Sensor is as a security system. Mounting this board to the top corner of a room allows you to detect the presence of motion with ease, and the use of a timed security circuit can trigger alarms at certain times of the day, or when no one is around.
Another potential use for the PIR (Motion) Sensor is in wildlife cameras. A camera and sensor are connected together such that any wildlife that crosses the camera's field of view results in pictures being taken. This is especially helpful for those monitoring the local environment for biodiversity and changes in habitats.
Thirdly, this project can be used in conjunction with smart homes that need to detect the presence of individuals in a room. Hallways with automatic lights on the ceiling can pick up those walking by and automatically turns on lights. Once motion is no longer detected, the lights can be turned off.
So, to summarise the PIR (Motion) Sensor, it is a small, yet very capable motion sensor that works exceptionally well in security, monitoring, and tracking applications. The ability to accept a wide range of input voltages, a single digital output, and adjustable delay make this a highly versatile module that will make any motion detection application trivial! If you want to grab one of these, head over to the electromaker store, whip out that debit card, and get spending! Thanks for watching, and I’ll see you next time.
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