Arduino/C2/Analog-to-Digital-Conversion/English-timed

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
00:19	DHT11 Temperature and Humidity sensor
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
00:50	We require few external components such as DHT11 sensor
00:57	Breadboard and Jumper wires
01:02	In this tutorial, we will detect the temperature and humidity using DHT11 sensor.
01:09	This sensor collects analog values and gives it to Arduino Uno.
01:15	Arduino ADC pins will convert these analog values to digital values.
01:21	Next, we will understand the concept of resolution.
01:25	Arduino Uno has 10-bit resolution.
01:28	This means, it can detect (2 to the power of 10) i.e. 1024 discrete analog levels.
01:37	Resolution is the smallest change that can be measured
01:42	Arduino gives 5 Volts output voltage, so 5 Volts divided by 1024 levels gives 4.89 miliVolts.
01:56	That means, Arduino Uno can be sensitive to a minimal change of 4.8 9miliVolts.
02:04	This shows the circuit connection for DHT11 with Arduino.
02:10	Arduino Uno has 6 in-built ADC channels (A0 to A5).
02:17	ADC channels read analog signal in the range of 0-5 Volts.
02:23	Pin 1 of the DHT11 sensor is connected to 5 Volts pin of Arduino.
02:30	Pin 2 of the DHT11 sensor is the Data pin.
02:35	This Data pin of the sensor is connected to analog pin A0 of Arduino.
02:42	Pin 3 of the DHT11 sensor is connected to the ground pin of the Arduino.
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.
02:57	Open Arduino IDE.
03:00	First we need to download the DHT11 arduino library to run this program.
03:06	Click on Sketch menu in the menu bar.
03:10	Select Include Library and then click on Manage Libraries option.
03:16	A new window will appear.
03:19	In the top right corner, we can see a search tab. Here, type DHT11 and press Enter.
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.
03:39	In the version drop down box, we can select the latest version of the library.
03:45	Click on Install button to install the library.
03:49	The DHT11 library is now installed in the Arduino IDE.
03:54	Click on the Close button at the right bottom of the window.
03:59	Let us add this library to the program.
04:02	Click on the Sketch menu and select Include Library.
04:06	Newly downloaded library usually appear at the end.
04:11	So scroll down to the bottom of the list and select SimpleDHT.
04:17	We can see the header file SimpleDHT.h added in the code window.
04:24	Type the code as shown.
04:27	Here we have initialized the data pin of DHT11 sensor which is connected to A0.
04:34	This command creates a DHT object.
04:38	Inside void setup function, type the code as shown:
04:43	Serial.begin() function initiate the serial communication.
04:48	It sets the data rate in bits per second for serial data transmission.
04:54	9600 represents the baud rate.
04:58	delay(500) is the delay time for the sensor to boot.
05:03	Serial.print command prints the header as specified here.
05:08	Now we will write the code for void loop.
05:12	We have created two variables, temperature and humidity for DHT sensor output.
05:20	dht11.read, reads the data from the sensor.
05:25	It stores the result in microcontroller’s register.
05:29	These lines prints the temperature in degree Celsius and humidity in percentage.
05:36	delay(2000) updates the current humidity and temperature readings every 2 seconds.
05:43	This code is available in the Code files link of this tutorial. You can download and use it.
05:51	Click on the compile button to verify your program.
05:55	A pop up window will appear to save the current program. Save the program as DHT11.
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.
06:15	For this, click on the Tools menu and select Serial monitor.
06:21	The serial monitor window opens.
06:25	Temperature and humidity of the current place is displayed as expected. Close the window.
06:33	Next we will see the output in the serial plotter.
06:37	Let us modify the program.
06:40	Comment the line Serial.print( “Temperature & Humidity :”); as shown.
06:47	This will not print the text Temperature and Humidity.
06:52	For plotting, we require only the values of temperature and humidity.
06:58	Let us upload the current program to see the results on serial plotter.
07:04	Click on the tools menu and select serial plotter. The serial plotter window opens.
07:12	We can see two lines simultaneously plotting the points.
07:18	The blue line indicates the temperature which is around 28 to 30 °C.
07:25	The red line is the humidity reading which is near to 45%.
07:31	The readings will vary depending upon where the experiment is done.
07:36	Now cover the sensor with your hands and you will see the fluctuating readings.
07:43	Close the window.
07:45	It is useful for humidity readings between 20% to 80% with ∓5% RH i.e. (Relative Humidity)
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.

Contributors and Content Editors

PoojaMoolya