This document provides instructions for a project to build an alarm with light using an Arduino. The project will teach students to use an Arduino to produce light with an LED and sound with a buzzer. It includes a sample Arduino sketch that uses digitalWrite to turn the LED on and off and the tone function to play tones of different frequencies on the buzzer. Students are asked to modify values in the sketch to change the tones and explore the relationship between frequency and sound.

1. ICT and Programming
Project 2:Buzzer
Alarm with Light
Mr Gee, Amir, Ms Siti
Science Educators
STEM INC
Science Centre Singapore

2. What do these things have in
common?

3. Objective
In this project, you will learn to use the Arduino to:
•Produce light in an LED and sound through a buzzer

4. What You Will Need
Breadboard Red LED
100 Ω resistor Jumper wires
Piezo buzzer

5. Setup

6. The Arduino Integrated
Development Environment (IDE)
Creating the sketch:
Step 1: Double click the icon to open up the IDE

7. Let’s get to coding!
Buzzer Alarm with Light
int ledPin = 13; // LED connected to pin 13
int tonePin = 8; // buzzer alarm connected
to pin 8
void setup()
{
pinMode(ledPin, OUTPUT); // sets the buzzer alarm as
output
}

8. Let’s get to coding!
void loop() // run over and over again forever
{
digitalWrite(ledPin, HIGH); // turn the LED on (HIGH is the
voltage level)
tone (tonePin, 200, 250); // play a tone on tone pin with 200
Hz and 250 ms
delay(500); // wait for 0.5 s
digitalWrite(ledPin, LOW); // turn the LED off (LOW is the
voltage level)
tone (tonePin, 600, 250); // Play a tone on tone pin with 600
Hz and 250 ms
delay(500); // wait for 0.5 s
}

9. Uploading the Sketch
Step 1: Click the Verify/Compile button and check for errors in
the code.
Step 2: Click the Upload button.

10. Let’s think!
1. What happens in the circuit after the code was uploaded?
2. Change the value highlighted in yellow to a higher value, say
500. Compile/Verify the program before uploading the program
again. What happens?
3. Change the value highlighted in yellow to a lower value, say
100. Compile/Verify the program before uploading the program
again. What happens?

11. Let’s think!
1. Change the circled number to a lower value, say 100.
Compile/Verify the program before uploading the program
again. What happens?
The first beep is at lower pitch.
2. Try changing the underlined value to a higher value, say 600.
Compile/Verify the program before uploading the program
again. What happens?
The first beep remains on for a longer time.(600 ms)

12. Challenge
Listen to the alarm played by the educator. Can you create
something similar to that?

13. What have you learnt?
• The tone function in a sketch
• The function of the piezo buzzer
• Relationship between frequency and sound