PoojaMoolya at 05:50, 23 January 2020

2020-01-23T05:50:43Z

PoojaMoolya: Created page with " {| border=1 | '''Time''' | '''Narration''' |- |00:01 | Welcome to the spoken tutorial on '''Pulse Width Modulation.''' |- |00:06 | In this tutorial we will learn abou..."

2020-01-23T05:28:44Z

Created page with " {| border=1 | '''Time''' | '''Narration''' |- |00:01 | Welcome to the spoken tutorial on '''Pulse Width Modulation.''' |- |00:06 | In this tutorial we will learn abou..."

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{| border=1
| '''Time'''
| '''Narration'''

|-
|00:01
| Welcome to the spoken tutorial on '''Pulse Width Modulation.'''

|-
|00:06
| In this tutorial we will learn about: '''PWM i.e Pulse Width modulation'''

|-
|00:13
| '''PWM Duty Cycle'''

|-
|00:16
| '''PWM Frequency'''

'''L293D Motor Driver IC'''

|-
|00:24
| To follow this tutorial, you should have basic knowledge of:

'''Electronics''' and '''C or C++''' programming language

|-
|00:35
| To record this tutorial, I am using

'''Arduino Uno board'''

|-
| 00:40
| '''Ubuntu Linux 16.04 OS'''

'''Arduino IDE '''

|-
|00:46
| We will also require some external '''components''' such as:

'''Breadboard'''

|-
|00:53
| '''10K Ohm Potentiometer'''

'''LED'''

|-
| 00:58
| '''220 ohm Resistor'''

|-
| 01:01
| '''Jumper Wires'''

'''Push Button'''

|-
|01:05
|'''DC Motor'''

|-
|01:08
| and '''L293D Motor Driver IC'''

|-
|01:14
| '''PWM signal '''is a square wave signal which has a high frequency i.e '''1KHz'''.

|-
| 01:22
| '''PWM''' is a technique by which the width of the '''pulse''' is varied.

|-
|01:28
| It is done while keeping the frequency of wave constant.

|-
|01:33
| '''PWM signal''' consists of two main properties that define its behaviour.

|-
|01:40
| They are '''Duty Cycle''' and '''Frequency.'''

|-
|01:44
| It is the percentage of time, a '''digital signal''' is on, over a period of time.

|-
|01:50
| '''Duty cycle''' can be varied from 0% to 100%..

|-
|01:55
| The formula to calculate the percentage of '''duty cycle''' is shown here.

|-
|02:01
| '''tON '''is equal to the duration of time when '''signal''' is high.

|-
|02:06
| '''tOFF '''is equal to the duration of time when '''signal''' is low.

|-
|02:11
| '''Time Period''' is''' tON + tOFF'''.

i.e. It is equal to the sum of '''on''' time and '''off''' time of '''PWM signal'''.

|-
|02:24
| Frequency determines how fast the '''PWM''' completes a '''cycle'''.

|-
|02:29
| i.e. How fast it switches from '''HIGH''' to '''LOW''' states.

|-
|02:34
|We will perform one simple experiment by varying '''duty cycle'''.

|-
|02:39
| This will control the brightness of '''LED'''.

|-
|02:43
|'''Arduino Uno''' has 6 '''PWM channels.'''

|-
|02:48
| Pins 3, 5, 6, 9, 10, 11 on '''Arduino Uno''' are '''PWM channels.'''

|-
|02:58
| '''PWM channels''' are denoted by''' tilde '''sign.

|-
|03:02
| Let us see the circuit connection now.

|-
|03:05
|Connect '''anode''' leg of the '''LED''' to pin 9 of '''Arduino''' through '''220 ohm resistor.'''

|-
|03:13
| Connect '''cathode''' leg of the '''LED''' to '''ground'''.

|-
|03:17
| This is the '''live setup''' of the connection.

|-
|03:20
| Do the connection as shown in the image.

|-
|03:23
| Let us open the''' Arduino IDE'''.

We will write a '''program''' to change the brightness of '''LED''' using '''PWM''' pin.

|-
|03:32
| Type the code as shown.

|-
|03:35
| We have assigned the '''PWM pin 9''' to the '''variable LED_Pin.'''

|-
|03:42
| We have initialized '''duty_cycle_value''' as 1 for an '''LED''' to turn '''ON'''.

|-
|03:51
| Inside '''void setup''', we will write '''pinMode function'''.

|-
|03:56
| We have declared '''pin 9''' of the '''Arduino''' as '''OUTPUT'''.

|-
|04:01
| Inside '''void loop function''' we will write this code.

Let me explain the code.

|-
|04:08
| '''While''' loop executes the code till the '''duty_cycle_value''' is below 255.

|-
|04:17
| '''analogWrite() function''' is used to generate '''PWM signal'''.

|-
|04:22
| We are passing two '''parameters'''. i.e '''PWM''' pin number and the '''duty cycle''' value.

|-
|04:30
| The '''duty cycle''' value must be between 0 to 255 i.e between 0voltz and 5Voltz

|-
|04:40
| We will keep a '''delay''' of 3000 millisecond i.e. 3 seconds

|-
|04:46
| Click on the '''compile''' button to verify your '''program'''.

|-
|04:51
| A pop up window will appear to save the current '''program'''.

|-
|04:55
| Let us save the '''program''' as '''LED_Brightness '''and click on the '''Save''' button.

|-
|05:03
| Now click on '''upload''' button to upload the current '''program''' on '''Arduino''' board.

|-
|05:09
| We can see the brightness of '''LED''' increasing gradually.

|-
| 05:15
| Next, we will do an experiment to control the speed and direction of a '''DC motor.'''

|-
|05:22
| This is the '''pinout''' diagram of '''L293D motor driver IC.'''

|-
|05:28
| The speed of the '''motor''' is controlled by '''EN 1''' and '''EN 2''' of the '''IC'''.

|-
|05:36
| The direction of the '''motor''' is controlled by '''IN1, IN2, IN3, IN4''' of the '''IC'''.

|-
|05:45
| We can control 2 '''motors''' at a time using this '''IC'''.

|-
|05:50
| In our experiment, we will connect only one '''DC motor'''.

|-
| 05:55
| Let us see the circuit connection now.

|-
|05:58
| Pin 1, pin 8 and pin 16 of '''driver IC''' are connected to''' 5V.'''

|-
|06:05
| Pin 4 and pin 5 of '''driver IC''' are connected to '''ground'''.

|-
|06:11
| Pin 2 and pin 7 of '''driver IC''' are connected to pin 11 and pin 10 of '''Arduino'''.

|-
|06:20
| 2 '''push buttons''' are connected to pin 12 and pin 13 of '''Arduino'''.

|-
|06:27
| These '''push buttons''' are used to control the direction of '''DC motor'''.

|-
|06:33
| '''10Kohm potentiometer''' is connected to control the speed of the '''DC motor'''.

|-
|06:39
| Middle pin of '''potentiometer''' is connected to '''analog''' pin A0.

|-
|06:45
| Pin 3 and pin 6 of '''driver IC''' are connected to '''DC motor'''.

|-
|06:51
| Do the connection as shown in the image.

|-
|06:55
| This is the '''live setup''' of the connection, as shown in the image.

|-
|07:00
| I have fixed a wheel on the shaft of the '''motor'''.

|-
|07:04
| This will help to see the rotation and varying speed of '''motor''' clearly.

|-
|07:10
| Now we will write a '''program''' for this circuit to work.

|-
|07:14
| Let’s switch to '''Arduino IDE.'''

|-
|07:18
| Type the code as shown here.

We have initialized the connection between '''Arduino''' and '''driver IC'''.

|-
|07:28
| '''Potentiometer''' pin is connected to '''analog''' pin A0.

|-
|07:33
| '''fwdbuttonPin '''is the '''variable''' for '''push button''' connected to pin 13 of '''Arduino'''.

|-
|07:40
| '''bckbuttonPin '''is the '''variable''' for '''push button''' connected to pin 12 of '''Arduino'''.

|-
|07:47
| '''ICpin2''' and''' ICpin7 '''are the '''variables''' which indicate pin 2 and pin 7 of the '''IC'''.

|-
|07:57
| They are connected to pin 11 and pin 10 of '''Arduino''' respectively.

|-
|08:04
| First we make sure that the '''potentiometer, motor''' and '''push buttons''' are in '''LOW''' state.

For that we have initialised it to 0.

|-
|08:15
| In the''' void setup function''', we will write this code.

|-
|08:20
| '''pinMode function''' defines the pins as '''INPUT''' or '''OUTPUT'''.

|-
|08:25
| '''fwdbuttonPin''' and '''bckbuttonPin''' are set to '''INPUT_PULLUP '''mode.

|-
|08:32
| In this mode we are using '''Arduino’s''' internal '''pull-up resistors'''.

|-
|08:38
| To know about the '''INPUT_PULLUP''' mode, refer to the manual.

|-
|08:44
| Click on the '''Help menu''' in the '''Arduino IDE.'''

Then click on '''Reference.'''

|-
|08:50
| This opens an offline page in your browser.

Scroll down.

|-
|08:55
| Click on '''INPUT_PULLUP. '''

|-
| 09:00
| Switch back to '''Arduino IDE.'''

|-
|09:03
| '''ICpin2 '''and''' ICpin7 '''are set to '''OUTPUT''' mode to drive the '''motor'''.

|-
|09:10
| Next we will write the code in '''void loop function'''.

|-
|09:14
| '''analogRead command''' will read the '''analog''' value from the '''potentiometer'''.

|-
|09:20
| This value will be given to '''analog''' pin A0.

|-
|09:24
| Depending upon the '''potentiometer''' value, the speed of the '''motor''' will vary.

|-
|09:30
| '''map command''' will convert the '''analog''' value to '''digital'''.

|-
|09:35
| '''fwdbuttonState''' and '''bckbuttonState''' will fetch the '''signal''' if '''push button''' is pressed.

|-
| 09:43
| The '''IF command''' checks, if the '''push button''' connected to pin 12 or pin 13 is pressed.

|-
|09:50
| This enables the '''motor''' to rotate in a clockwise or anti-clockwise direction.

|-
|09:56
| Suppose we don’t press any of the two '''buttons'''.

|-
|10:00
| Then the '''else command''' ensures the '''motor''' is in '''OFF''' condition.

|-
|10:05
| This code is available in the '''Code file''' link of this tutorial

You can download and use it.

|-
|10:13
| Click on the '''compile''' button to verify the '''program'''.

|-
|10:17
| Let us save the program as '''PWM_Motor''' and click on the '''Save''' button.

|-
|10:25
| Now click on '''upload''' button to '''upload''' the current '''program''' on '''Arduino'''.

|-
|10:31
| Now we will see the output of the above '''program'''.

|-
|10:35
| I’ll press the '''push button''' connected to '''pin 13'''.

|-
|10:39
| We can see the '''motor''' rotating in the clockwise direction.

|-
|10:43
| Now I will release the '''push button'''.

|-
|10:47
| The '''motor''' will stop rotating and it will be in '''OFF''' state.

|-
|10:52
| Now again, I’ll press the '''push button''' connected to '''pin 12'''.

|-
|10:57
| We can see the '''motor''' is rotating in anti-clockwise direction.

|-
|11:02
| We can change the speed of '''motor''' by adjusting the '''potentiometer''' connected to A0.

|-
| 11:14
| This brings us to the end of this tutorial. Let us summarize.

|-
|11:20
| In this tutorial, we learnt about

'''Pulse Width modulation'''

|-
|11:26
| '''PWM Duty Cycle'''

|-
|11:29
| '''PWM Frequency '''and How to control speed and direction of '''DC motor.'''

|-
|11:38
| As an '''assignment''':

Connect a '''Buzzer''' instead of '''LED''' in the above circuit connection.

|-
|11:45
| Upload the same '''program''' and check the output.

|-
|11:49
| You would hear a noise with different frequencies.

|-
| 11:53
| Here is the output of the assignment.

|-
|12:01
| The video at the following link summarizes the '''Spoken Tutorial''' project.

Please download and watch it.

|-
|12:09
| The''' Spoken Tutorial Project''' Team conducts '''workshops''' and gives certificates.

For more details, please write to us.

|-
|12:19
| Please post your timed queries in this '''forum'''.

|-
|12:23
| '''Spoken Tutorial''' project is funded by '''MHRD, Government of India'''.

|-
| 12:29
| This tutorial has been contributed by FOSSEE and Spoken Tutorial Project, IIT Bombay.

And this is Saurabh signing off.

Thanks for joining.

|}

@@ Line 210: / Line 210: @@
 |-
 |04:30
-| The '''duty cycle''' value must be between 0 to 255 i.e between 0voltz and 5Voltz
+| The '''duty cycle''' value must be between 0 to 255 i.e between 0 volts and 5 Volts
 |-

Arduino/C2/Pulse-Width-Modulation/English-timed - Revision history

PoojaMoolya at 05:50, 23 January 2020

PoojaMoolya: Created page with " {| border=1 | '''Time''' | '''Narration''' |- |00:01 | Welcome to the spoken tutorial on '''Pulse Width Modulation.''' |- |00:06 | In this tutorial we will learn abou..."