View source for Arduino/C2/Analog-to-Digital-Conversion/English-timed


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| '''Time''' 
| '''Narration''' 

|- 
| 00:01
| Welcome to the '''Spoken Tutorial''' on '''Analog to Digital Conversion '''using''' Arduino.''' 

|- 
| 00:07
| In this tutorial, we will learn about :  '''ADC i.e. Analog to Digital Conversion''' 

|- 
| 00:14
| '''ADC pins''' in '''Arduino''' 

'''ADC Resolution''' 
 
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| 00:19
| '''DHT11 Temperature and Humidity''' sensor 

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| 00:23
| '''Serial Monitor '''and''' Serial Plotter''' 

|- 
| 00:27
| To follow this tutorial, you should have a basic knowledge of: 

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

|- 
| 00:37
| To record this tutorial, I am using: 

'''Arduino Uno board''' 

|- 
| 00:43
| '''Ubuntu Linux 16.04 OS''' 

and  '''Arduino IDE''' 

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| 00:50
| We require few '''external components''' such as 

'''DHT11 sensor''' 

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| 00:57
| '''Breadboard''' and  '''Jumper wires''' 

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| 01:02
| In this tutorial, we will detect the temperature and humidity using '''DHT11 sensor.''' 

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| 01:09
| This '''sensor''' collects '''analog''' values and gives it to '''Arduino Uno'''. 

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| 01:15
|'''Arduino ADC''' pins will convert these '''analog''' values to '''digital''' values. 

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| 01:21
| Next, we will understand the concept of''' resolution.''' 

|- 
|01:25
|'''Arduino Uno''' has '''10-bit resolution'''.

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| 01:28
|This means, it can detect (2 to the power of 10) i.e. '''1024 discrete analog levels.''' 

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| 01:37
| '''Resolution''' is the '''smallest change''' that can be measured 

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| 01:42
|'''Arduino''' gives 5Voltz output voltage, so 5Voltz divided by 1024 levels gives '''4.89miliVoltz.''' 

|- 
| 01:56
| That means, '''Arduino Uno '''can be '''sensitive''' to a minimal change of '''4.89miliVoltz.''' 

|- 
| 02:04
| This shows the circuit connection for '''DHT11''' with '''Arduino'''. 

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| 02:10
| '''Arduino Uno''' has '''6 '''in-built''' ADC channels''' ('''A0 to A5'''). 

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| 02:17
| '''ADC channels''' read '''analog signal''' in the range of '''0-5Voltz.''' 

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| 02:23
| '''Pin 1 '''of the '''DHT11 sensor '''is connected to 5Voltz pin of '''Arduino'''. 

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| 02:30
| '''Pin 2 '''of the '''DHT11 sensor''' is the''' Data''' pin. 

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| 02:35
| This''' Data''' pin of the '''sensor''' is connected to''' analog''' pin '''A0 '''of '''Arduino'''. 

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| 02:42
| '''Pin 3 '''of the '''DHT11 sensor''' is connected to the '''ground''' pin of the '''Arduino'''. 

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| 02:48
| This is the''' live setup''' of the connection, as shown in the circuit diagram. 

|- 
| 02:53
| Now we will write the program in''' Arduino IDE.''' 

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| 02:57
|Open '''Arduino IDE.''' 

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| 03:00
| First we need to download the''' DHT11 arduino library''' to run this program. 

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|03:06
| Click on '''Sketch''' menu in the menu bar. 

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| 03:10
|Select '''Include Library''' and then click on '''Manage Libraries''' option. 

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| 03:16
| A new window will appear. 

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| 03:19
|In the top right corner, we can see a '''search''' tab. 

Here, type '''DHT11''' and press '''Enter'''. 

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| 03:28
| We can see various '''libraries''' for''' DHT11 sensor.''' 
 
|- 
| 03:33
|Scroll down to the bottom of the screen and select '''SimpleDHT''' by '''Winlin.''' 

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| 03:39
|In the '''version''' drop down box, we can select the latest version of the '''library'''. 

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| 03:45
|Click on '''Install''' button to install the '''library'''. 

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| 03:49
| The '''DHT11 library''' is now installed in the '''Arduino IDE'''. 

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| 03:54
|Click on the '''Close''' button at the right bottom of the window. 

|- 
|03:59
| Let us add this '''library''' to the '''program'''. 

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| 04:02
|Click on the '''Sketch '''menu and select '''Include Library.''' 

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| 04:06
|Newly downloaded '''library''' usually appear at the end. 

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| 04:11
|So scroll down to the bottom of the list and select '''SimpleDHT.''' 

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| 04:17
| We can see the header file''' SimpleDHT.h '''added in the code window. 

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| 04:24
| Type the code as shown. 

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| 04:27
|Here we have initialized the data pin of '''DHT11 sensor''' which is connected to '''A0.''' 

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| 04:34
|This '''command''' creates a '''DHT object'''. 
 
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| 04:38
| Inside '''void setup function''', type the code as shown: 

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| 04:43
|'''Serial.begin() function''' initiate the '''serial communication'''. 

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| 04:48
|It sets the '''data rate''' in''' bits per second''' for '''serial data transmission.''' 

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| 04:54
|'''9600''' represents the '''baud rate'''. 

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| 04:58
|'''delay(500)''' is the '''delay time''' for the '''sensor''' to '''boot'''. 

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| 05:03
|'''Serial.print command''' prints the '''header''' as specified here. 

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| 05:08
| Now we will write the code for '''void loop.''' 

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| 05:12
|We have created two '''variables, temperature''' and '''humidity''' for '''DHT sensor''' output. 

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| 05:20
|'''dht11.read,''' reads the '''data''' from the '''sensor'''. 

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| 05:25
|It stores the result in '''microcontroller’s register.''' 

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| 05:29
|These lines prints the temperature in '''degree Celsius''' and humidity in '''percentage'''. 

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| 05:36
|'''delay(2000)''' updates the current humidity and temperature readings every''' 2 seconds.''' 

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| 05:43
|This code is available in the '''Code files''' link of this tutorial. 
 
You can download and use it. 

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| 05:51
| Click on the''' compile''' button to verify your''' program.''' 

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| 05:55
|A pop up window will appear to save the current '''program'''. 

Save the '''program''' as '''DHT11.''' 

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| 06:05
|Now click on '''upload''' button to upload the current '''program''' on''' Arduino.''' 

|- 
| 06:11
| We will see the output in the '''Serial monitor screen.''' 

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| 06:15
|For this, click on the''' Tools '''menu and select '''Serial monitor.''' 

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| 06:21
|The '''serial monitor''' window opens. 

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| 06:25
|Temperature and humidity of the current place is displayed as expected. 

Close the window. 

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| 06:33
| Next we will see the output in the '''serial plotter'''. 

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| 06:37
| Let us modify the '''program'''. 

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| 06:40
|'''Comment''' the line '''Serial.print( “Temperature & Humidity :”);''' as shown. 

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| 06:47
|This will not print the text '''Temperature''' and '''Humidity'''. 

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| 06:52
|For plotting, we require only the values of temperature and humidity. 

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| 06:58
| Let us upload the current '''program''' to see the results on '''serial plotter'''. 

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| 07:04
|Click on the''' tools menu''' and select '''serial plotter. ''' 

The '''serial plotter''' window opens. 

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| 07:12
| We can see two lines simultaneously plotting the points. 

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| 07:18
|The blue line indicates the temperature which is around 28 to 30 °C. 

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| 07:25
|The red line is the humidity reading which is near to 45%. 

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| 07:31
|The readings will vary depending upon where the experiment is done. 

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| 07:36
|Now cover the '''sensor''' with your hands and you will see the fluctuating readings. 

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| 07:43
|Close the window. 

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| 07:45
| It is useful for '''humidity''' readings between '''20% to 80% '''with''' ∓5% RH''' i.e. '''(Relative Humidity)''' 

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| 07:56
| It is useful for temperature readings between''' 0 to 50 °C '''with''' ∓2 °C''' 

|- 
| 08:06
| This brings us to the end of this tutorial. Let us summarize. 

|- 
| 08:12
| In this tutorial, we learnt about: 

'''ADC i.e. Analog to Digital Conversion''' 

|- 
| 08:19
| '''ADC pins''' in '''Arduino''' 

'''ADC Resolution''' 

|- 
| 08:25
| '''DHT11 Temperature''' and '''Humidity sensor''' 

'''Serial Monitor '''and''' Serial Plotter''' 

|- 
| 08:33
| As an assignment: 

Raise an alarm by glowing the built in '''LED''' '''pin 13''' of the '''Arduino''' 

|- 
| 08:41
| Modify the above existing code. 

Hint: Use '''If-else statement'''. 

|- 
|08:48
| Add 1 or 2 °C to the temperature value that you get on the '''serial monitor'''. 

|- 
| 08:55
| To increase the temperature reading, cover the '''DHT11 sensor '''with your hands. 

|- 
| 09:02
| Refer to the '''Assignment''' link of this tutorial for the source code. 

|- 
|09:07
| The video at the following link summarizes the '''Spoken Tutorial Project''' 

Please download and watch it. 

|- 
| 09:15
| The '''Spoken Tutorial Project''' Team conducts workshops and gives certificates. 

|- 
|09:21
| Please post your timed queries in this '''forum''' 

|- 
| 09:27
| '''Spoken Tutorial Project''' is funded by''' MHRD, Government of India''' 

|- 
| 09:34
| This tutorial has been contributed by '''FOSSEE''' and Spoken Tutorial Project, IIT Bombay. 

And this is Saurabh signing off. 

Thanks for joining. 

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