How to Build a Motion Sensor – What You Need to Know

Building a motion sensor is a very technical job. If all the accessories are not present, then you might not be able to build a motion sensor that functions appropriately. In our quest to help you with your digital security needs, we have put this article together to show you how to build a motion sensor.

But before we get into that, let us walk you through the different types of motion sensors you can build.

What are the Types Motion Sensors?

The types of motion sensors used for constructing a security systems include:

i. Passive Infrared Sensors

ii. Microwave sensors

iii. Dual technology motion sensors

iv. Area reflective motion sensors

v. Ultrasonic motion sensors

vi Vibration detectors

Passive Infrared (PIR) Sensors

The passive infrared motion sensors are one of the most generally used motion sensors in home security systems. Their principle of operation is based on heat and movement within an enclosed environment.

These sensors can easily detect heat and motion from immediate surroundings by detecting changes in levels of infrared energy. While this may sound good, bear in mind that these sensors are very easily obstructed by a number of heat sources and sunlight, which therefore makes it more suitable for movement detection indoors.

Microwave (MW) Sensors

Microwave motion sensors employ the use of microwave radar technology in detecting motion. These sensors, unlike the PIR sensors, cover a much wider area and more accurately detect motion and hence prevent false alarms.

These motion detectors are also entirely defenseless to electrical disturbances and may place a high demand on your money.

Dual Technology Motion Sensors

What are Dual technology motion sensors?

A dual technology motion sensor is also known as a hybrid (combined) motion sensor. It combines features of both active and passive sensors. A microwave sensor is an active sensor that covers a much larger area and is more accurately able to detect motion.

However, a standalone microwave motion sensor cannot be trusted completely to detect motion accurately. Hence, these sensors are usually paired with PIR motion-detection technology. This combined technology ensures that the system is less liable to give off false alarms.

For this sensor to give off an alarm, both sensors have to be triggered, and this doesn’t provide the same level of safety as a separate PIR and microwave sensors would.

Area Reflective Motion Sensor

What is an area reflective motion sensor and how does it work?

An area reflective motion sensor is able to provide stable motion detection that is not affected by the condition or position of the item or person being monitored.

This sensor emits infrared rays towards the object or person and is able to detect and determine the presence of a person within a specified distance. Additionally, this sensor has a high reflectance of up to 90% and still performs even when the detection surface is greasy or dirty.

Ultrasonic Motion Sensor

The ultrasonic motion detector is an electronic device that employs ultrasound technology in detecting motion. These sensors are not only sensitive and have fast response time, but they do not also require physical contact with the object to detect motion.

Additionally, these sensors utilize the ultrasonic waves that are both inaudible and invisible to humans in an area to give precise and accurate measurements about the proximity of an object or human.

Vibration Detectors

Vibration detectors, as the name implies, are sensors that so easily detect, monitor, measure, and analyze the vibration of an object or person.

These sensors are quite flexible and can measure a variety of processes ranging from temperature change, acceleration, force, and electrical charge. These sensors can either be purchased or made in the comfort of your homes.

Buy the Hosmart Outdoor Motion Sensor

How to Set Up Motion Sensors?

To set up a motion sensor for the first time, do the following:

i. Unbox the motion detector

ii. Choose an appropriate installation location

iii. Mount the motion sensor

iv. Connect the motion sensor to a remote device

v. Configure the motion detection settings

vi. Maintain the motion detector

Unbox the Motion Detector

Every motion sensor pack comes with a list of instructions given by the manufacturer and mounting hardware to make setting up easier.  Make sure to unbox your motion detector, carefully go through these instructions and seek guidance if need be. If your sensor has two separate batteries, make sure to insert them correctly into your device.

Choose an Appropriate Installation Location

Deciding on a location is of utmost importance as mounting your device. Make sure to choose the best sensor placement as this determines the extent of coverage your device can cover.

Ideal locations for mounting are corners of a room or the hallway as these sensors are patterned with angled edges that can so easily fit into any corner in your room. Also, avoid placing your device above a piece of relatively large furniture or wooden item as this tends to limit the passage of infrared rays.

Consider mounting your device high on the wall to get optimal coverage. Bear in mind also that mounting your device opposite a room or the main entrance to the hallway enables it to pick up signals of motion immediately.

Mount the Motion Sensor

When mounting a PIR motion sensor, you can rest assured that the condition of your wall has little or no importance as this motion sensor is lightweight and has little or no impact on your wall.

A simple standard screwdriver can get the job done. However, an electronic screwdriver would come in handy as it will but only make the task faster. Exclusively, mounting your device becomes a whole lot easier if it comes with a mounting bracket.

Most motion sensors are accompanied by a wall bracket that simply requires you to mount on the wall before clipping the motion detector back in.

Connect the Sensor to a Remote Device

Instructions are very vital when it comes to the installation and connection of your motion detector. Remember to strictly follow the instructions on the manufacturer’s manual when connecting your device to your system.

These instructions can take you through the entire DIY procedure. You can easily select settings for your device by only using your system’s application on your smartphone or using your system’s main keyboard.

However, if your device is a smart motion detector, such as the Samsung SmartThings motion detector, you could easily connect the device to light or smart devices via the SmartThings network such that bright light comes on whenever motion is detected.

Configure the Motion Detection Settings

A wide variety of motion sensors are built with three primary settings: the instant mode, the entry delay mode, and the interior follow-up mode. These settings have their peculiarities in motion detection and analysis.

While the instant mode immediately triggers an alarm when movement is detected, the entry delay mode operates on a time-frequency between 30 – 60 seconds such that even when motion is detected, an alarm is only triggered after the system has been disarmed.

However, the interior follow-up mode applies the entry delay principle but only triggers an alarm if it comes in contact with a door. Moreover, if motion is detected without a door contact, the motion sensor immediately sounds an alarm.

Maintain the Motion Detector

Installation isn’t all there is to motion detectors. Maintaining your device is also very important. Over time, grit and dust can build up on the surface of your device, which interferes with the infrared energy and thus reducing its efficiency in detecting motion.

In addition, try cleaning the device once in a while with a slightly damp or dry cloth. Ensure that the fabric has little or no water in it. If you ever consider refurbishing or painting, make sure your motion detector is removed and neatly tucked away. If your motion sensor gets stained with paint, you may need to find a replacement for it.

Buy the Fosmon WaveLink 51005HOM Wireless Motion Detector

How to Make a Simple Motion Sensor Light (PIR)

To make a PIR motion sensor, follow these steps:

i. Gather the needed accessories

ii. Construct the circuit

iii. Build a breadboard circuit

iv. Set up an eagle PCB file

v. Transfer the PCB file

vi. Etch the PCB file

vii. Drill holes

viii. Solder all screw terminals

Gather the Needed Accessories

The components needed to construct a simple motion sensor light are easily gotten from electronic and robotic stores. If you want to evade the stress of getting these components yourself, you could as well order them on Amazon. The necessary components needed are:

A PIR motion detector — preferably HC-SRT501. This particular motion sensor has pinout -VCC, output, GND from back left to the right direction. Other accessories include BC547 NPN Transistor, Screw terminals, pins, and small copper furniture.

Construct the Circuit

How to Construct the Circuit of a PIR Motion Sensor Light

To construct a circuit that can help in running an infrared light, its output pin should move from low to high voltage resulting in a 3.3V supply in the output pin. This output pin will then be used as a switching device to switch the transistor LED on and off.

The light-emitting diodes (LEDs) are connected in series such that they consume the entire 12V supply provided by the battery, which in turn prevents burning. A higher supply voltage of more than 12V would burn out the LEDs. This circuit is controlled by two basic components: An NPN transistor and a PIR motion detector.

Build a Breadboard Circuit

A breadboard is a solderless reusable construction base for prototyping of electronics. Unlike the Veroboard, the breadboard doesn’t need a soldering work to be able to conduct electricity.

Most technicians use the breadboard to test the working effectiveness of a circuit before implementing it on Veroboard. Additionally, building a circuit on a breadboard gives you a heads up on wrong connections and enables you to work faster when using on the Veroboard.

Set Up an Eagle PCB File

What is an Eagle PCB File?

Eagle Printed Circuit Board (PCB) is an electronic design automation application that employs the schematic capture technology, aided router, and computer-aided manufacturing. This PCB is where the idealized circuit is brought to life. 

Transfer the PCB File

Since your PCB file is ready to be used, all you have to do is press hardly with an iron for about 4 -5 minutes and immediately dip into the water. Once that is done, gently rub the paper on the PCB file with your thumb and ensure that the artwork is attached to the PCB.

Etch the PCB File

Next, put your PCB file in Ferric Chloride. On the other hand, you may want to try out Hydrogen peroxide for this experiment.

Drill Holes

Try drilling holes with a screwdriver. Better luck you have if you have an electronic screwdriver or drill, as this makes the process faster.

Solder All Screw Terminals

Ensure that your drill terminal is the only 1mm, then solder the right angle header and led. After that, solder your LEDs to your copper board (Veroboard). You can use any color of your choice.

Next, solder the transistor to the Veroboard and ensure that the flat side of the transistor is facing the LEDs. Then solder the PIR and power it.

Video: Making a Simple DIY Motion Sensor

If you want to build a homemade motion sensor, check out this video…

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Building a motion sensor is a very technical task. However, there is a simple motion sensor that just about anyone can set up. You just have to gather the needed accessories, build the circuits, transfer the artwork, and solder the screw terminals.

How to Build a Motion Sensor – Related FAQs

How Do You Trick a Motion Sensor?

To trick a motion sensor so that it is not triggered when it detects movement, shied your body with styrofoam. Bypassing door sensors and window sensors is not all that difficult because they come with magnetic field energy that trips if they are high enough. The person trying to bypass motion sensors should know the extent of their coverage and steer clear of it.

The most effective way of tricking motion sensors is to reset them by directing infrared or near-infrared light to a specific wavelength. This will blind the motion sensors until the light is removed from their direction.

Are There Light Bulbs that are Motion Sensor?

There are smart bulbs that come with motion sensors. This type of security device is usually meant for outdoor use. The light bulb will come on when the motion sensor notices any movement. For the battery not to run down or to conserve electricity, the light bulb staying time can be adjusted. Most of these light bulbs are also designed to be energy-saving.

Motion sensor light bulbs are exquisitely constructed to penetrate light walls, glass and veneer. The downside of this is that they usually give lots of false alarms. But then, they offer more protection.

Can a Shadow Set Off a Motion Detector?

A motion detector can be set off by the cast of a shadow because that’s how they have been programed to work. Even leaves blowing in a tree can set off motion detectors unless they are installed in an appropriate location. To ensure that a motion sensor is not activated by shadows or wind, reduce its sensitivity.

Using heavy blinds can ensure that motion detectors do not detect small changes in infrared energy caused by shadows. The manufacturer of a motion detector can adjust its settings to stop it from giving false alarms.

Do Motion Sensors Have Cameras in Them?

Some motion sensors come with built-in cameras. These devices are known as video motion sensors. They are a combination of an advanced motion detection and video processing system. The motion detectors will start recording once they notice any changes in motion. This type of security devices help to conserve storage space because they only record when it is necessary.

The two features of this device can be used independently and still very easy to install and operate. If a motion sensor does not come with an inbuilt camera, users can incorporate a pin-hole camera and it will work just as well.

How Do I Connect Two Motion Sensors Together?

To connect two motion detectors together, wires them in parallel direction to each other. The lights will not go off until the one of the motion sensor’s staying time has elapsed. But note that two motion sensors can only be connected together if they are designed to be controlled by a switch.

Also, if a motion sensor is designed to switch mains voltage with a relay to the white line, then it can be paired with another motion sensor. The downside of this framework is that electricity consumption is doubled. Hence, reducing the staying time of the lights is important.

Can a Television Set Off a Motion Detector?

A Television cannot trigger motion detectors because they are designed to only detect motion of physical objects and not variations in sound or light. The working principle of motion sensors is different from that of the human eye. Rather, they use heat, light, and microwave signals to detect movement. The television does not move, so a motion sensor will not notice its presence even if it is in its coverage area.

There are many things that causes a motion detector to give false alarms, but television is not one of them.

Do Overhangs Decrease the Coverage Range of Motion Sensors?

Hanging a motion sensor detector over a large piece of furniture or under an overhang reduces the cover range of the sensor. Remember how wearing a hat reduces your field of view? So it is when a motion sensor is under an overhang.  The sensing angle is reduced by two, and so is the cover range of the sensor.

Also, infrared rays are essential in detecting motion. So, be sure that the infrared rays emitted from the sensor are not blocked or disturbed. A motion sensor’s wave cannot necessarily penetrate through hard walls and large furniture.