In this next project, we’ll show you how we used a PIR sensor to detect motion, and integrated it into a creative casing that sort of resembles a large sea mammal often referred to as a “sea cow”.

This wing-flapping manatee, which we are aware is a bit of an odd mixture, is lots of fun to make and proved very useful for us in our workshop. We programmed the Manatee to flap its wings when motion is detected so it serves as a sort of “greeter” in the doorway of our workshop. You can also use this for other applications and add more functions to it, which we’ll discuss a bit later.

Putting together the circuit

To build the circuit for this project, we’ll be using an Arduino Pro Mini 328 and pair it with the Infrared PIR Sensor.

The PIR module uses infra-red radiation emitted from humans or animals to detect movement within 6 meters and you can control its sensitivity.

To power up this project we used a 9V battery. We decided to use a battery for this project because we didn’t have a close available power outlet, but if you do, you can also hook it up using a 12v adapter and then you won’t have to worry about the battery running out.


To make the flapping motion for the wings we paired the Arduino board with a small servo motor, weighing about 20 grams. The object attached to the servo will have a 180-degree rotational capability with a maximum speed of 0.18 sec per 60 degrees.


This build is pretty simple and the circuit can be done following the step-by-step wiring guide on our app.

Once the circuit is complete, you can move on to the code. As with all the projects we publish here, you’ll have to modify the original code you got from, if you want to get the same functionality that we did. The code we used can be downloaded here, and we’re more than happy to hear updates and modifications if you made any.

Physical parts


The Flying manatee is made of different 3D printed parts:

  • Front and Back covers
  • Two wings and pivots, one for each side
  • A cog wheel for the servo motor

You can find the .STL files for on our Hackster project hub under the Flying Manatee project, in the “custom parts and enclosures” section.

You may also be able to see that we created a custom PCB with a perforated breadboard for this project, to avoid using a bulky breadboard.

After you print the parts and place the PCB in place, you can put screws to hold the parts together and you’re pretty much done.

Customize the design

As always, we’d like to share with you a few modifications we thought about. For starters, you can replace Infrared PIR Motion Sensor with an Ultrasonic Range Finder. This way you’ll be able to not only detect movement but measure distance and if you really want to go crazy, you can get the Manatee’s wings to flap according to distance. In fact, you can do something even better. You could pair the range finder and the motion sensor together. This will help you detect movement and also determine the distance of the moving object. To identify distance, you could program the Manatee, using code, to flap its wings a certain number of times.

Another option is to incorporate an LCD display into the design. The display can be used to indicate distance while the flapping of the wings indicates movement.

You could also try adding a Piezo Speaker instead of the LCD display and program sounds that change as the object gets closer.

Knock knock who’s there

The Flying Manatee can be used for a lot of things. You don’t have to limit it to detecting random movement. For instance, you can use it as a silent security assistant by placing it near your door.  If there’s someone trying to get in, the flapping wings will alert you and give you time to dial 911. You can probably include LEDs in the wings so that they light up when they move. This would make it convenient for night time use.

What will you create?

We hope you have a great time building this project. We’d love to see your pics and videos. Also, tell us about any new ideas that you might have tried with this build. We’d love to learn from you.