How to Make an OwlBot: the Bird Intimidator – Part 3: Flashing Red LED Eyes

In this part of the project we’re going to be performing the third step of what will eventually be the OwlBot. The OwlBot will be a device that can be used as a bird intimidation tool to scare away pesky birds in the yard, around the house or barn, at restaurants, or in trees, bushes, and gardens. Hence, the phrase, “The Bird Intimidator”.

To learn why the OwlBot was created and what problem it was to solve, check out the story behind it all here.

The OwlBot (a.k.a. “The Bird Intimidator”) we’ll be making will be done in several parts. The OwlBot is an ambitious project. When complete, the OwlBot will sense motion. When motion is detected, the OwlBot should make owl sounds, perform varying movements, and flash its red eyes to intimidate and scare away pests. To put together all these tasks in one page would be too long and cumbersome, so we’ve decided to split each process we want the OwlBot to do into easy to accomplish chunks or parts as we continue on our goal to complete the OwlBot.

This is Part 3

This is part three. This third part of the OwlBot project will involve setting up its ability to have flashing red LED eyes when motion has been detected via the passive infrared sensor (PIR) we set up with our Arduino Uno in Part 1 of this OwlBot project series. While the LEDs flash, the owl sounds play from the MP3 player and dual speakers we added to our OwlBot prototype in Part 2 of this project series.

Our goal at the end of this part of the project will be to have the Arduino Uno tell the MP3 player to play owl sounds from an MP3 file to the speakers and to flash two red LEDs when motion is detected by the PIR sensor. Again, we’ll use the serial port on the Arduino IDE to print out whether or not motion is detected.

Goal of Part 3 of the OwlBot Project

A motionless, plastic great horned owl deterrent with a staring gaze might not do much over time. For the OwlBot to be effective enough to deter birds from nesting in an area throughout the year requires lifelike actions, like sound and movement. Our goal for Part 1 of the OwlBot project was to first get it to detect motion:

1. Motion Sensing: When the OwlBot is complete, we want it to be able to sense motion of a bird or other creatures, and when it does to start making owl hooting sounds. We also want it to perform various movements, as well as flash its red eyes as an added effect to help deter pesky animals in the surrounding area. We’ll end up having all these actions done in sync when motion is detected, and we’ll use an HC-SR501 PIR sensor to get the OwlBot to detect motion.

Our goal for Part 2 of the OwlBot project was to get it to play owl sounds when motion is detected by the PIR sensor:

1. Sound: We want the OwlBot to make owl sounds to notify any birds around that there’s an owl in the vicinity and that they should get the heck outta dodge. This purpose is to deter the birds from nesting close by. We’ll be using the DFRobot DFPlayer Pro Mini MP3 Player to store an audio file of owl sounds to be played. We don’t want the OwlBot to be hooting non-stop all day and night though, so we’ll use the PIR sensor to help the OwlBot sense when a bird has come near it. When a bird comes within the OwlBot’s field-of-view, then it can start making its owl calls. Of course, the OwlBot will not quite be smart enough to distinguish between a human passing by or a bird, but it’ll work fine, so we’ll just ignore those details, for now.

Now, our goal for Part 3 is to add two red LEDs to our prototype to act as the OwlBot’s eyes. When motion is detected by the PIR sensor, the owl sounds should play from the file on the MP3 player we added from Part 2 of this project, and also flash the two red LED eyes at the same time:

1. Flashing LEDs: We want the OwlBot to have a pair of flashing red LED eyes to add another characteristic to it to assist in its ability to intimidate pesky creatures within its vicinity. Not only will these flashing red LED eyes have a purpose for scaring away birds, squirrels, cats, and the like, but it should also make it look cool too 😎.

Flat Top Clear Lens Red LEDs

In order to add some animation to the OwlBot’s eyes, we’ll use a couple of red LEDs that we’ll have the Arduino to flash when motion is detected by the PIR sensor we added to the prototype back in Part 1 of this project.

I’ve chosen a flat top, clear lens, red LED variety. I chose this type LED because I didn’t want to have the typical round domed red colored LEDs sticking out like two sore thumbs next to the OwlBot’s eyes when installed on its face later on in the finished project. You can have a look at what the owl looks like here. Having a couple clear lens LEDs that are flat head would look nicer, in my opinion. You can choose whatever LEDs are available to you or that you like best.

(This parts list is a continuation of the previous parts lists from Parts 1 and 2, of the OwlBot project.)

Breadboard Prototyping Parts List

1. 2x Flat Top Clear Lens Red LED
2. 2x 680Ω Resistor
3. Male-to-Male Jumper Wires

Tools Used in Project

1. The Ultimate DIY 3220-Point Breadboard (Optional)

Previously, for Part 2 of the OwlBot prototype we successfully made all the connections needed for the Arduino Uno and DFPlayer Pro Mini MP3 Player, and created the code to play owl sounds when motion was detected by the PIR sensor. Now we need to add to this prototype the red LEDs that will act as the OwlBot’s spooky eyes. We also need to update the code and add to it the functionality we need to get the LEDs to flash when motion is detected by the PIR sensor.

Again, like I mentioned in the previous parts of this build, I will be using The Ultimate DIY 3220-Point Breadboard that was made from a separate project. I may refer to The Ultimate DIY 3220-Point Breadboard as “TUDIY” throughout this project to save me from having to say it every time.

DON’T WORRY! Even though I’ll be discussing how to make connections on TUDIY throughout the following prototyping steps, I’ll provide images of how to hook up items on a generic breadboard, so you can still follow along!

LED #1

Take an LED and place the cathode (-) lead into a point on the negative rail of the negative supply of the Arduino we established on the breadboard of the Setting up 5V Power from the Arduino section in Part 1 of the OwlBot project.

Next, place the anode (+) lead of the LED into a point on the breadboard that isn’t inline with anything else. In my case, I’ve placed the first LED onto the breadboard with its anode at point a15 and its cathode in a point on the negative supply of the Arduino’s 5V supply that was established on the breadboard in Part 1.

LED #2

Now, take the second LED and place the cathode (-) lead into a point on the negative rail of the negative supply of the Arduino we established on the breadboard of the Setting up 5V Power from the Arduino section in Part 1 of the OwlBot project.

Next, place the anode (+) lead of the second LED into a point on the breadboard that isn’t inline with anything else. In my case, I’ve placed the second LED onto the breadboard with its anode at point a19 and its cathode in a point on the negative supply of the Arduino’s 5V supply that was established on the breadboard in Part 1.

Now that we have the LEDs in place on the breadboard, it’s time to install the current limiting resistors. We’re going to use a 680Ω resistor as a current limiting resistor for each red LED.

Resistor #1

Take one of your resistors and place one of its leads at a point inline with the first LED we installed. In my case, I placed one of the leads of a 680Ω resistor at point c15, inline with LED #1, from Step 1, above.

Next, place the other lead of the resistor into a point across the point separator/divider (grooved gap) of the breadboard, as shown in the image below. In my case, I’ve placed the other lead of the resistor into point f15, on the breadboard.

Resistor #2

Take another 680Ω resistor and place one of its leads at a point inline with the second LED we installed. In my case, I placed one of the leads of the resistor at point c19, inline with LED #2, from Step 1, above.

Next, place the other lead of the resistor into a point across the point separator/divider (grooved gap) of the breadboard, as shown in the image below. In my case, I’ve placed the other lead of the resistor into point f19, on the breadboard.

At this point, we have gotten the LEDs in place and we’ve connected their current limiting resistors. Next, we just need to make the final connections to the Arduino. I’ve grabbed two orange male-to-male jumper wires to complete the connection from each of the LEDs, their current limiting resistors, and to the Arduino.

Take one of the orange jumper wires and place one end of it into a point inline with the first LED and resistor. In my case, I placed one end of an orange jumper wire at point j15. Next, place the other end of the orange jumper wire into pin 4 of the Arduino.

Now, take the other orange jumper wire and place one end of it into a point inline with the second LED and resistor. In my case, I placed one end of the orange jumper wire at point j19. Next, place the other end of the orange jumper wire into pin 5 of the Arduino.

That’s it for our connections! Next, we just need to add to our code from Part 2 of the OwlBot project the functionality of blinking the red LEDs when motion is detected by the PIR sensor.

Now that you've assembled the third part of the OwlBot prototype, it's time to update the code we created in Part 2 of this project!

If you're interested in continuing this fun project and are ready to get the code for your Arduino for Part 3, then head over to our page and go to the section titled Programming the Arduino to Make to Flash the LEDs here.

At our page titled "How to Make an OwlBot: The Bird Intimidator – Part 3: Flashing Red LED Eyes", you'll find a more detailed version for the steps of this prototype build, more close up images, and documents, as well as a more thorough parts list. You'll also find the steps and accompanying videos to instruct you to complete this project in its entirety.

Thanks for trying out this neat project. Hope you had fun! Stay tuned for Part 4, where we'll add a couple of solenoids and a DC motor to this project to make our OwlBot have movement when motion is detected. Remember to keep at it and stay motivated!