|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
|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.|
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|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.|