The document introduces Arduino and Raspberry Pi for internet of things applications. It discusses the basics of both platforms, including components, programming, and interfacing with sensors and actuators. It provides examples of blinking LEDs, reading button input, and controlling an LED based on light level. Finally, it compares Arduino and Raspberry Pi, concluding they are best used together to take advantage of their complementary capabilities.

1. Using Arduino and Raspberry Pi
for Internet of Things
Sudar Muthu (@sudarmuthu)
http://hardwarefun.com/
http://github.com/sudar

2. Who am I?
 Research Engineer by profession
 I build robots as a hobby
 Playing with Arduino for more than 4 years
 Blogger about Arduino at http://hardwarefun.com
 Moderator for Arduino India forum
http://hardwarefun.com 2

3. Objective
 Introduce Arduino
 Introduce Raspberry Pi
 Emphasis on IoT
 See how both can be used for IoT
http://hardwarefun.com 3

4. Arduino
http://hardwarefun.com 4

5. What is Arduino?
 Visual Basic for hardware
 Includes both Hardware and software
http://hardwarefun.com 5
Photo credit Arduino team

6. Different Arduino types
 Arduino Uno (The one I am going to use today)
 Arduino Mega
 Arduino Due
 Lillypad
 Arduino BT
 Arduino Ethernet
 .. and clones
http://hardwarefun.com 6

7. Getting to know the Arduino
http://hardwarefun.com 7

8. Specs (Uno, Leonardo)
Type Value
Microcontroller ATmega328
Operating Voltage 5v
Digital I/O Pins 14 (of which 6 provide PWM output)
Analog Input Pins 6
Flash Memory 32 KB (ATmega328) of which 0.5 KB used
by bootloader
SRAM 2 KB (ATmega328)
EEPROM 1 KB (ATmega328)
Clock Speed 16 MHz
http://hardwarefun.com 8

9. Identify these components in
 Microcontroller
 Power jacket
 USB jacket
 Digital pins
 Analog pins
 Reset button
Arduino
http://hardwarefun.com 9

10. Identify these components in
Arduino
 Voltage Regulator
 Power Pins (how many are there?)
 Ground Pins (how many are there?)
 Vin Pin
 Rx and Tx Pins
 ICSP Headers
http://hardwarefun.com 10

11. Identify these components in
 Power Led
 Rx and Tx Led’s
 Test Led
 Crystal
 Anything else?
Arduino
http://hardwarefun.com 11

12. Powering up Arduino
http://hardwarefun.com 12

13. Different ways to power up Arduino
 Using USB cable
 Using DC power jacket
 Giving voltage directly into Vin pin
 Giving regulated voltage directly into 5V pin
http://hardwarefun.com 13

14. Setting up Arduino
http://hardwarefun.com 14

15. Testing the setup with a “Hello
World” program
http://hardwarefun.com 15

16. Blinking LED
http://hardwarefun.com 16

17. Making a LED blink
 Insert a LED in pin 13
 Open File->Examples->Basics->Blink
 Select Tools->Boards->Arduino Uno
 Select File->Upload (or press ctrl+u)
 You should get the message “Done upload”
 Your Led should blink
 Congrats you can program Arduino now 
http://hardwarefun.com 17

18. People with electronics background
Did I miss anything?
http://hardwarefun.com 18

19. People with electronics background
Did I miss anything?
Hint: Ohm’s Law
http://hardwarefun.com 19

20. Anatomy of an Arduino sketch
http://hardwarefun.com 20

21. Printing values through Serial
 Uno has one UART hardware port, using which we
can exchange information with computer
 Very useful for debugging
 Works at a specified baud rate
 Use Serial Monitor to read values
 SoftwareSerial is also available
http://hardwarefun.com 21

22. Breadboard Basics
http://hardwarefun.com 22

23. How to use a breadboard
 The first two and the last two rows are connected
 In all the other rows, columns are connected
 Connect the first and last row to power
 Connect the second and second last row to ground
http://hardwarefun.com 23

24. Digital Input and Output
http://hardwarefun.com 24

25. Digital Input
http://hardwarefun.com 25

26. Digital Output
The LED blink that we did at “setting up Arduino” is
Digital output
http://hardwarefun.com 26

27. Analog Input
http://hardwarefun.com 27

28. Reading Analog values from sensors
 Connect the LDR on pin A0 and Gnd
 LDR’s resistance varies based on the amount of light
present
 Read the current value using analogRead()
 Print the value in Serial Monitor
http://hardwarefun.com 28

29. Control an LED based on light
void setup(){
pinMode(13, OUTPUT);
}
void loop(){
int val = analogRead(A0);
if (val > 50) {
digitalWrite(13, HIGH);
} else {
digitalWrite(13, LOW);
}
}
http://hardwarefun.com 29

30. Analog Output
http://hardwarefun.com 30

31. Analog Output
 What is PWM?
 Analog like behavior using digital output
 Works by switching the LED on and off regularly
 Changing the brightness of a Led
http://hardwarefun.com 31

32. This is just the tip of an
iceberg
http://hardwarefun.com 32
There are tons of other
features to Arduino which I
have not talked about

33. Internet of Things
http://hardwarefun.com 33

34. http://hardwarefun.com 34
"Internet of Things" by Wilgengebroed on Flickr

35. LoT is an overloaded term
But I like this definition…
“The Internet of Things is the interconnection of
uniquely identifiable embedded computing devices
within the existing Internet infrastructure”
http://hardwarefun.com 35

36. Connecting Arduino to Internet
 Ethernet Shield
 WIFI Shield
 3G Shield
 Using another intermediate component
http://hardwarefun.com 36

37. Demo of network connectivity
using Arduino
http://hardwarefun.com 37

38. Let’s take a break 
http://hardwarefun.com 38

39. Raspberry Pi

40. Credit Card Sized
Computer
http://hardwarefun.com 40

41. GPIO Pins
http://hardwarefun.com 41 http://learn.adafruit.com/assets/3052

42. Setup Python
sudo apt-get install python-dev
sudo apt-get install python-rpi.gpio
http://hardwarefun.com 42

43. Set the status of GPIO Pins
https://github.com/sudar/r http://hardwarefun.com asp4b3erry-pi-sketches/blob/master/led-blink/led-blink.py

44. Set the status of GPIO Pins
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(12, GPIO.OUT)
try:
while True:
GPIO.output(12, GPIO.HIGH)
time.sleep(1)
GPIO.output(12, GPIO.LOW)
time.sleep(1)
finally:
GPIO.cleanup()
https://github.com/sudar/raspberry-http://hardwarefun.com 44 pi-sketches/blob/master/led-blink/led-blink.py

45. Demo
Let there be Light
https://github.com/sudar/r http://hardwarefun.com 45aspberry-pi-sketches/blob/master/led-blink/led-blink.py

46. Changing the brightness of the LED
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(12, GPIO.OUT)
p = GPIO.PWM(12, 50) # channel=12 frequency=50Hz
p.start(0)
try:
while True:
for dc in range(0, 101, 5):
p.ChangeDutyCycle(dc)
time.sleep(0.1)
for dc in range(100, -1, -5):
p.ChangeDutyCycle(dc)
time.sleep(0.1)
finally:
p.stop()
GPIO.cleanup()
http://hardwarefun.com 46
https://github.com/sudar/raspberry-pi-sketches/blob/master/led-blink/pwm.py

47. Demo
Can you see the brightness changing?
https://github.com/sudar/raspberry-http://hardwarefun.com 47 pi-sketches/blob/master/led-blink/pwm.py

48. Reading the status of the Pin
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(11, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
try:
while True:
if GPIO.input(11):
print "Button is on"
else:
print "Button is off"
time.sleep(0.1)
finally:
GPIO.cleanup()
http://hardwarefun.com 48
https://github.com/sudar/raspberry-pi-sketches/blob/master/button-input/button-input.py

49. Reading the status of the Pin
http://hardwarefun.com 49
https://github.com/sudar/raspberry-pi-sketches/blob/master/button-input/button-input.py

50. Demo
What happens when the button is pressed?
http://hardwarefun.com 50
https://github.com/sudar/raspberry-pi-sketches/blob/master/button-input/button-input.py

51. Combining Input and Output
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(11, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
GPIO.setup(12, GPIO.OUT)
try:
while True:
if GPIO.input(11):
print "Button is on"
GPIO.output(12, 1)
else:
GPIO.output(12, 0)
time.sleep(0.1)
finally:
GPIO.cleanup()
http://hardwarefun.com 51
https://github.com/sudar/raspberry-pi-sketches/blob/master/button-and-led/button-and-led.py

52. Combining Input and Output
http://hardwarefun.com 52
https://github.com/sudar/raspberry-pi-sketches/blob/master/button-and-led/button-and-led.py

53. Demo
Let’s control the LED by pressing the button
http://hardwarefun.com 53
https://github.com/sudar/raspberry-pi-sketches/blob/master/button-and-led/button-and-led.py

54. What more can be done?
http://hardwarefun.com 54

55. More protocols
 I2C
 SPI
 Serial
http://hardwarefun.com 55

56. Interacting with webcam
 “PyGame” provides easy interface
 Can get fancy using “opencv”
 Both USB and GPIO interface are supported
http://hardwarefun.com 56

57. Distributed Computing
 Each Pi can be used as cheap node
 Form grids using a cluster of Pi’s
 Can share CPU, memory and disk space
http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/
distributed-computing/
http://hardwarefun.com 57

58. Limitations
 No built-in Analog to Digital support
 Can’t run Inductive load (motors)
 Is not real-time (CPU might be busy)
 No “safe circuits” present
 Operates at 3.3V and is not directly compatible with
Arduino voltage
http://hardwarefun.com 58

59. Arduino vs Raspberry Pi
for IoT
http://hardwarefun.com 59

60. Advantages of Raspberry Pi
 Entire Linux software stack is available
 It is very easy to connect to internet
 Can be programmed using variety of programming
languages
http://hardwarefun.com 60

61. Disadvantage of Raspberry Pi
 Accessing hardware is not real-time. If the CPU is
busy, then interfacing with hardware can be delayed
 No built-in Analog to Digital converter available
 Does not have enough power to drive inductive loads
 The hardware design is not open source. Even though
it is not a big deal, for some people it might a deal
breaker
http://hardwarefun.com 61

62. Advantages of Arduino
 Very easy to get started
 Very easy to extend it and has tons of user
contributed shields and libraries. Shields are available
to do pretty much anything
 Can be used to for real-time applications
 Everything (both hardware, software and IDE) are
open source
 Not much programming knowledge needed to do
basic stuff
http://hardwarefun.com 62

63. Disadvantages of Arduino
 Not very powerful when compared with Raspberry Pi
(Micro processor vs Micro controller)
 You need to program using either Arduino or C/C++
(or assembly if you really want to)
 Connecting to internet is slightly difficult (you have
shields and libraries, but is not straight forward), but
not impossible.
http://hardwarefun.com 63

64. In Short..
Feature Raspberry Pi Arduino
Processor Speed 700 MHz 16 MHz
Programming Language No limit Arduino, C/C++
Real-time Hardware No real-time In real-time
Analog to Digital Convertor No Yes
Hardware Design Closed source Open source
Internet Connection Very easy Not easy, but doable
http://hardwarefun.com 64

65. My Solution?
http://hardwarefun.com 65

66. Use both together 
Best of both worlds
http://hardwarefun.com 66
http://learn.adafruit.com/assets/3199 http://learn.adafruit.com/assets/2123

67. Links
 Source code - https://github.com/sudar/raspberry-pi-sketches/
 My blog - http://hardwarefun.com
 Python GPIO - https://code.google.com/p/raspberry-gpio-
python/
 Distributed computing using Pi -
http://www.cl.cam.ac.uk/projects/raspberrypi/tutorial
s/distributed-computing/
http://hardwarefun.com 67

68. Links
 Arduino – http://arduino.cc
 Asimi – A simple bot using Arduino
http://hardwarefun.com/project/asimi
 Getting started with hardware programming
http://hardwarefun.com/tutorials/getting-started-with-hardware-
programming
 Getting started with Arduino
http://hardwarefun.com/tutorials/getting-started-with-arduino-
and-avr
http://hardwarefun.com 68

69. Questions
Thank You
Sudar Muthu (@sudarmuthu)
http://hardwarefun.com/
https://github.com/sudar/arduino-robotics-workshop
https://github.com/sudar/raspberry-pi-sketches
http://hardwarefun.com 69