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Time Narration
00:01 Welcome to the Spoken Tutorial on Display counter using Arduino.
00:07 In this tutorial, we will learn to:

connect an LCD and a Push button to Arduino board and

write a program to increase the count whenever the pushbutton is pressed.

00:22 To follow this tutorial, you should have:

basic knowledge of electronics and

basic knowledge of C or C++ programming language.

00:34 To record this tutorial, I am using:

Arduino UNO Board,

Ubuntu Linux 14.04 operating system and

Arduino IDE.

00:47 In an earlier tutorial, in this series, we had created a circuit using Arduino and LCD.

We will use the same circuit in this tutorial.

01:00 Here, we will add a pushbutton and make a simple counter.
01:06 We have already learnt about the working of pushbutton in an earlier tutorial.
01:12 Now, let us learn the connection circuit details.
01:17 A pushbutton is connected to a 100 ohm resistor.
01:22 The pushbutton is connected to pin number 7 and a 100 ohm resistor is connected to the ground.
01:31 All other connections are exactly the same as in our previous experiment.
01:37 This is the live setup of the connection as shown in the circuit diagram.
01:44 Now, we will write a program in the Arduino IDE. So, let’s switch to the Arduino IDE.
01:54 First, we need to include the Liquid crystal library.
01:59 Type the code as shown.
02:02 I have initialized a variable lcd of type LiquidCrystal.
02:08 Here, pin number 12 is initialized as Register Select and pin number 11 as Enable.
02:19 The next 4 parameters represent data lines of LCD.
02:25 In the void setup function, type: lcd.begin 16 comma 2 as shown.

This command initializes the LCD with rows and columns.

02:41 Next we will setup the pin number 7 as INPUT. Type the code as shown.
02:49 In another way, we can store the pin number in a variable pbutton.

Let us define the pbutton variable as shown.

03:01 Now we will write the code for void loop.

Whenever the pushbutton is pressed, one count is increased on the LCD.

03:11 We will write a simple 'if' statement to check whether the pushbutton is pressed or not.
03:19 Before displaying the count, let us check the status of the button.
03:25 This command will set the cursor position in the LCD.

lcd.print will print the message.

03:35 We will now compile and upload the program. Now, I will press the pushbutton.
03:43 Here, we see the message “button pressed” in the LCD.

It shows that the pushbutton is working successfully.

03:54 Next, we will modify the program to set a counter.
03:58 We need a variable for counter. Now, we will initialize the variable count to zero.
04:08 Modify the print statement as shown here.

count++ will increase the count by one, each time the button is pressed.

04:21 Let us now compile and upload the program. Now, I will press the pushbutton.
04:29 It didn't work as expected. We see a different count displayed here.

Why is this so?

04:37 This is because we specified the status for button pressed.

But we didn't mention the status for button released.

04:46 The output shows the incremented number based on the button pressed time.
04:52 So, we will write a 'while' statement as shown here.
04:57 This will display the count when the pushbutton is in pressed state.

That means the pin 7 is in HIGH mode.

05:07 When you release the button, the state is LOW and it will come out of the 'while' loop.
05:14 Let me explain the program.
05:17 The program starts with initialization of the LCD. We have the variable pbutton and count.
05:26 Inside the void setup function, we have initialized the LCD with 16 columns and 2 rows.

Then the pinMode is input for the pin number 7.

05:42 In the void loop function, we are checking the condition whether the pushbutton is HIGH or not.
05:49 When the pushbutton is pressed, the cursor is set to position zero comma zero.
05:56 The lcd.print statement will print the count value.

Initially count is zero. Count plus plus would be 1.

06:09 When the button is released, it will break the while loop and come out of the loop.
06:15 Again, if you press the button, the next iteration begins and it increases the count.
06:23 Let us compile and upload the program.
06:27 Now, I'll press the button once and release it.
06:32 Again I'll press and release the button. You can see that the count is increased whenever the button is pressed.
06:42 This brings us to the end of this tutorial. Let us summarize.
06:47 In this tutorial, we learnt to:

connect an LCD and pushbutton to Arduino board and

write a program to display the count whenever the pushbutton is pressed.

07:03 Do the following assignment.

Change the same program to display the count as 2,4,6 and so on.

Compile and upload the program.

And, observe the count displayed in the LCD.

07:21 The video at the following link summarizes the Spoken Tutorial project. Please download and watch it.
07:29 The Spoken Tutorial Project tTeam:

conducts workshops and gives certificates. For more details, please write to us.

07:38 Please post your timed queries in this forum.
07:42 Spoken Tutorial project is funded by NMEICT, MHRD, Government of India. More information on this mission is available at this link.
07:53 This tutorial has been contributed by FOSSEE' and Spoken Tutorial Project, IIT Bombay'. Thanks for watching.

Contributors and Content Editors

Pratik kamble, Sandhya.np14