Smart Devices with Arduino

Advanced Challenges

Learning Outcomes

  1. Learn how to use Sensors with Arduino

  2. Create a Smart Device for a real-world use case using Arduino

  3. Learn about Interfacing external devices with Arduino


In the previous Arduino challenge, you learned how to create a Knight Rider Styles light. You learned how to code a simple program using Arduino to create a program that exists in the real world. In this activity, we are going to explore what are the limits of the Arduino capability.


As discussed in the previous activity, Arduino is capable of interfacing the real world with the virtual world. Last activity we saw how OUTPUT can be sent to the real world from Arduino in the form of Light (Blinking of LEDs). But how does the Arduino board get INPUT from the real world? The answer is simple: USING SENSORS. 


A sensor is a device which detects or measures a physical property and records / indicates it. There are different types of sensors for measuring different physical properties of the environment like Light - Light Sensors, Sound - Sound Detector, Temperature - Thermistor Sensor, Humidity, etc. 



Today your challenge is to create a Smart Device. What is a Smart Device? It is a device which can perform its function without the need for human interaction. In this activity, you will be creating a simple Smart Device. Here is the problem: In modern days, robbery has become a big issue, specially in urban areas. Having a burglar alarm system is very costly & hard to maintain. Your challenge is to create a simple burglar alarm that sounds if someone enters through your main door.


To create this you will be using a Sensor called an Ultrasonic Sensor. As the name indicates, ultrasonic sensors measure distance by using ultrasonic waves. The sensor head emits an ultrasonic wave and receives the wave reflected from the target. Ultrasonic Sensors measure the distance to the target by measuring the time between the emission and reception. Simply said, it can detect depth. Ultrasound/sonar waves are used by ships to identify the depth of the sea level. The ship bottom sends an ultrasound signal to the seabed. Then it detects how much time it takes the signal to reflect and come back. The depth is simply calculated by; Distance = 0.5 * speed * time taken. 


The HC-SR04 ultrasonic sensor uses SONAR to determine the distance of an object just like the bats do. It offers excellent non-contact range detection with high accuracy and stable readings in an easy-to-use package from 2 cm to 400 cm or 1 inch to 13 feet. The operation is not affected by sunlight or black material, although acoustically, soft materials like cloth can be difficult to detect. It comes complete with an ultrasonic transmitter and receiver module.


How to complete the challenge:

Use the ultrasonic sensor to identify if a robber has entered through the door & use it to sound an alarm or buzzer. A tutorial on how you can implement this is given under the Learning Materials. Create a short video demonstrating the working device and write a blog post on how you solve the problem.


Upload/Submit the following 

* Video mp4 file of the demonstration of the project 

* Arduino code of the program 

* Blog Post link on how you solved the problem


Answer the questionnaire in Step 3 to complete this advanced challenge.


Good luck!

Learning Resources


Getting Familiar

To Complete, follow these steps :

Go through the learning resources given above, 

Step 1 :

Upload the deliverable

Click Here

Step 2 :

Answer the questions 

Click Here

Step 3 :