Internet of Things, refers to the network of interconnected devices that are embedded with sensors, software, and other technologies, enabling them to collect and exchange data over the internet.

Unit-II
IoT Physical Devices &
Endpoints
By
Dr. Anup Dey
Assistant Professor
School of CS & AI
SR University, Warangal

Outline
•Introduction to RaspberryPi
•About the RaspberryPi Board
• Hardware Layout and Pinouts
•Operating Systems on RaspberryPi
•Configuring RaspberryPi
•Programming RaspberryPi
•Connecting Raspberry Pi via SSH, Remote access tools,
•Interfacing DHT Sensor with Pi
•Pi as Webserver
• Pi Camera
• Image & Video Processing using Pi.

Raspberry Pi
•The Raspberry Pi is a series of small single-board computers developed in the
United Kingdom by the Raspberry Pi Foundation to promote the teaching of basic
computer science in schools and in developing countries.
• Raspberry Pi is a low-cost mini-computer with the physical size of a credit card.
• Raspberry Pi runs various ﬂavors of Linux and can perform almost all tasks that a
normal desktop computer can do.
• Raspberry Pi also allows interfacing sensors and actuators through the general
purpose I/O pins.
• Since Raspberry Pi runs Linux operating system, it supports Python "out of the
box".

Raspberry Pi …TimeLine
• The first generation (Raspberry Pi 1 Model B) was released in
February 2012.
• It was followed by a simpler and inexpensive model Model A.
• In 2014, the foundation released a board with an improved design in
Raspberry Pi 1 Model B+. These boards are approximately credit-
card sized and represent the standard mainline form-factor.
• Improved A+ and B+ models were released a year later. A "compute
module" was released in April 2014 for embedded applications, and
a Raspberry Pi Zero with smaller size and reduced input/output
(I/O) and general- purpose input/output (GPIO) capabilities was
released in November 2015 for US$5.

Raspberry Pi …TimeLine
• The Raspberry Pi 2 which added more RAM was released in
February 2015.
• Raspberry Pi 3 Model B released in February 2016, is bundled
with on-board WiFi, Bluetooth and USB boot capabilities.
• As of January 2017, Raspberry Pi 3 Model B is the newest
mainline Raspberry Pi. Raspberry Pi boards are priced between
US$5–35.
• As of 28 February 2017, the Raspberry Pi Zero W was launched,
which is identical to the Raspberry Pi Zero, but has the Wi-Fi and
Bluetooth functionality of the Raspberry Pi 3 for US$10.

Raspberry Pi …Features
• Features a Broadcom system on a chip which includes an ARM
compatible central processing unit (CPU) and an on-chip
graphics processing unit (GPU).
• CPU speed ranges from 700 MHz to 1.2 GHz for the Pi 3 and on
board memory range from 256 MB to 1 GB RAM.
• Secure Digital (SD) cards are used to store the operating
system and program memory in either the SDHC or MicroSDHC
sizes.

Raspberry Pi …Features
• Most boards have between one and four USB slots, HDMI and
composite video output, and a 3.5 mm phono jack for audio.
• Lower level output is provided by a number of GPIO pins
which support common protocols like I²C.
• The B-models have an 8P8C Ethernet port and the Pi 3 and Pi
Zero W have on board Wi-Fi 802.11n and Bluetooth.

Raspberry Pi …Operating System
• The Foundation provides Raspbian, a Debian- based Linux
distribution for download, as well as third party Ubuntu,
Windows 10 IOT Core, RISC OS, and specialised media center
distributions.
• It promotes Python and Scratch as the main programming
language, with support for many other languages.
• The default firmware is closed source, while an unofficial open
source is available.

Linux on Raspberry Pi
• Raspbian
• Raspbian Linux is a Debian Wheezy port optimized for
Raspberry Pi.
• Arch
• Arch is an Arch Linux port for AMD devices.
• Pidora
• Pidora Linux is a Fedora Linux optimized for Raspberry Pi.
• RaspBMC
• RaspBMC is an XBMC media-center distribution for Raspberry
Pi.
• OpenELEC
• OpenELEC is a fast and user-friendly XBMC media-center
distribution.
• RISC OS
• RISC OS is a very fast and compact operating system.

Raspberry Pi …Operating System

Hardware
• This block diagram depicts Models A, B, A+, and B+. Model
A, A+, and the Pi Zero lack the Ethernet and USB hub
components.
• The Ethernet adapter is internally connected to an
additional USB port.
• In Model A, A+, and the Pi Zero, the USB port is connected
directly to the system on a chip (SoC). On the Pi 1 Model
B+ and later models the USB/Ethernet chip contains a five-
point USB hub, of which four ports are available, while the
Pi 1 Model B only provides two.
• On the Pi Zero, the USBport is also connected directly to
the SoC, but it uses a micro USB (OTG) port.

Processor
• The Broadcom BCM2835 SoC used in the first generation Raspberry
Pi is somewhat equivalent to the chip used in first modern
generation smartphones (its CPU is an older ARMv6 architecture),
which includes a 700 MHz ARM1176JZF-S processor, VideoCore IV
graphics processing unit (GPU), and RAM.
• It has a level 1 (L1) cache of 16 KB and a level 2 (L2) cache of 128 KB.
The level 2 cache is used primarily by the GPU.The SoCis stacked
underneath the RAM chip, so only its edge is visible.
• The Raspberry Pi 2 uses a Broadcom BCM2836 SoC with a 900 MHz
32-bit quad-core ARM Cortex-A7 processor, with 256 KB shared L2
cache.
• The Raspberry Pi 3 uses a Broadcom BCM2837 SoCwith a 1.2 GHz
64-bit quad-core ARM Cortex-A53 processor, with 512 KB shared L2
cache

Performance
• The Raspberry Pi 3, with a quad-core Cortex-A53 processor,
is described as 10 times the performance of a Raspberry Pi
1.This was suggested to be highly dependent upon task
threading and instruction set use. Benchmarks showed the
Raspberry Pi 3 to be approximately 80% faster than the
Raspberry Pi 2 in parallelized tasks.
• Raspberry Pi 2 includes a quad-core Cortex-A7 CPU running
at 900 MHz and 1 GB RAM. It is described as 4–6 times more
powerful than its predecessor. The GPUis identical to the
original. In parallelized benchmarks, the Raspberry Pi 2
could be up to 14 times faster than a Raspberry Pi 1 Model
B+.

RAM
• The Raspberry Pi 2 and the Raspberry Pi 3
have 1 GB of RAM.
• The Raspberry Pi Zero and Zero W have
512 MB of RAM.

Networking
• The Model A, A+ and Pi Zero have no Ethernet circuitry
and are commonly connected to a network using an
external user-supplied USB Ethernet or Wi-Fi adapter.
• On the Model B and B+ the Ethernet port is provided by a
built-in USBEthernet adapter using the SMSCLAN9514
chip.
• The Raspberry Pi 3 and Pi Zero W (wireless) are equipped
with 2.4 GHz WiFi 802.11n (150 Mbit/s) and Bluetooth 4.1
(24 Mbit/s) based on Broadcom BCM43438 FullMAC chip
with no official support for Monitor mode but
implemented through unofficial firmware patching and
the Pi 3 also has a 10/100 Ethernet port.

Peripherals
• The Raspberry Pi may be operated with
any generic USB computer keyboard and
mouse.
• It may also be used with USB storage, USB
to MIDI converters, and virtually any other
device/component with USB capabilities.
• Other peripherals can be attached through
the various pins and connectors on the
surface of the Raspberry Pi.

Video Capabilities
• The video controller can emit standard modern TV
resolutions, such as HD and Full HD, and higher or
lower monitor resolutions and older standard CRT
TV resolutions.
• As shipped, it can emit these: 640×350 EGA;
640×480 VGA; 800×600 SVGA; 1024×768 XGA;
1280×720 720p HDTV; 1280×768 WXGA variant;
1280×800 WXGA variant; 1280×1024 SXGA;
1366×768 WXGA variant; 1400×1050 SXGA+;
1600×1200 UXGA; 1680×1050 WXGA+; 1920×1080
1080p HDTV; 1920×1200 WUXGA.

Raspberry Pi GPIO (40 Pin)
GND-8 pins, GPIO-26 pins, VCC-4 pins & Reserved-2 pins

Raspberry Pi Example:
Interfacing LED and switch with Raspberry Pi

Raspbian
• Raspbian is a Debian-based computer operating
system for Raspberry Pi. Since 2015 till now it is
officially provided by the Raspberry Pi Foundation as
the primary operating system for the family of
Raspberry Pi single-board computers.
• Raspbian was created by Mike Thompson and Peter
Green as an independent project.
• The initial build was completed in June 2012.
• The operating system is still under active
development. Raspbian is highly optimized for the
Raspberry Pi line's low-performance ARM CPUs.

Raspbian
• Raspbian uses PIXEL, Pi Improved Xwindows
Environment, Lightweight as its main desktop
environment as of the latest update.
• It is composed of a modified LXDE desktop
environment and the Openbox stacking window
manager with a new theme and few other changes.
• The distribution is shipped with a copy of computer
algebra program Mathematica and a version of
Minecraft called Minecraft Pi as well as a
lightweight version of Chromium as of the latest
version.

Basic features
• Developer
• OSfamily
Raspberry Pi Foundation
Unix-like
• Source model
• Latest release
Open source
Raspbian Jessie with PIXEL / 16.02.2017
• Marketing target Raspberry Pi
• Update method APT
• Package manager dpkg
• Platforms
• Kernel type
• Userland
ARM
Monolithic
GNU
• Default user interface PIXEL, LXDE
• License Free and open-source software licenses (mainly GPL)
• Official website https://www.raspberrypi.org/downloads/raspbian/

Finalization
• Complete the disk image writing process.
• Now insert the SD card in Raspberry Pi.
• Plug-in the power supply to the kit.
• Lets see the OS….

Programming Languages
• Python [Recommended for coding]
• C
• C++
• Java
• Scratch

Software Management on Pi
• sudo apt-get update
• sudo apt-get upgrade
• sudo apt-get install <package>
• sudo apt-get download <package>
• sudo apt-get remove <package>
• sudo apt-get purge <package>
• sudo apt-get dist-upgrade

Accessing Pi in Linux
• The Rpi can be accessed in Linux terminal
by secure shell.
• The Pi GUI can be accessed using VNC
server.

Raspberry Pi Interfaces
• Serial
• The serial interface on Raspberry Pi has receive (Rx) and
transmit (Tx) pins for communication with serial peripherals.
• SPI
• Serial Peripheral Interface (SPI) is a synchronous serial data
protocol used for communicating with one or more peripheral
devices.
• I2C
• The I2C interface pins on Raspberry Pi allow you to connect
hardware modules. I2C interface allows synchronous data
transfer with just two pins - SDA (data line) and SCL (clock
line).

Raspberry Pi Example:
Interfacing LED and switch with Raspberry Pi
from time import sleep
import RPi.GPIO as
GPIO
GPIO.setmode(GPIO.BC
M)
#Switch Pin
GPIO.setup(25,
GPIO.IN) #LED Pin
GPIO.setup(18, GPIO.OUT)
state=false
def toggleLED(pin):
state = not state
GPIO.output(pin,
state)
while True:
try:
if (GPIO.input(25) ==
True):
toggleLED(pin)
sleep(.01)
except
KeyboardInterrupt:
exit()

Raspberry Pi Camera Module
• The Raspberry Pi Camera Module v2 replaced the
original Camera Module in April 2016.
• The v2 Camera Module has a Sony IMX219 8-
megapixel sensor (compared to the 5-megapixel
OmniVision OV5647 sensor of the original camera).
• The Camera Module can be used to take high-
definition video, as well as stills photographs. It’s easy
to use for beginners, but has plenty to offer advanced
users if you’re looking to expand your knowledge.
• You can also use the libraries we bundle with the
camera to create effects.

• You can read all the gory details about IMX219
and the Exmor Rback-illuminated sensor
architecture on Sony’s website, but suffice to
say this is more than just a resolution upgrade:
it’s a leap forward in image quality, colour
fidelity, and low-light performance.
• It supports 1080p30, 720p60 and VGA90 video
modes, as well as still capture. It attaches via a
15cm ribbon cable to the CSI port on the
Raspberry Pi.

• The camera works with all models of
Raspberry Pi 1, 2, and 3.
• It can be accessed through the MMAL and
V4L APIs, and there are numerous third-
party libraries built for it, including the
Picamera Python library.
• The camera module is very popular in
home security applications, and in wildlife
camera traps.

Open Raspberry Pi Configuration

Rotating the Camera
You can rotate the image by 90, 180, or 270
degrees, or you can set it to 0 to reset.

Converting and Playing Video
• The video format need to get converted
to MP4. So install gpac.
sudo apt-get install gpac
• Now convert the video to MP4:
MP4Box -fps 30 -add video.h264 video.mp4

Effects
• The resolution of the capture is configurable.
• By default it’s set to the resolution of your monitor,
but the maximum resolution is 2592 x 1944 for still
photos and 1920 x 1080 for video recording.
• Try the following example to set the resolution to
max.
• Note that you’ll also need to set the frame rate to
15 to enable this maximum resolution:
• The minimum resolution allowed is 64 x 64. Try
taking one at that resolution.

Effects: Frame rate and Resolution

Annotation Text Sizes
• You can set the annotation text size with
the following code:
camera.annotate_text_size = 50
• Valid sizes are 6 to 160. The default is 32.

Annotation Colors
• You can also alter the annotation colours.
First of all, ensure that Color is imported
by amending your import line at the top:
from picamera import PiCamera, Color
• Then amend the rest of your code as
follows:

Image Effects
•
•
• You can use camera.image_effect to apply a
particular image effect.
Theoptions are: none, negative, solarize, sketch, denoise, emboss, oilpaint, hatch, gpen,
pastel, watercolor, film, blur, saturation, colorswap, washedout, posterise, colorpoint,
colorbalance, cartoon, deinterlace1, and deinterlace2.
Thedefault isnone.

AWB mode
• You can use camera.awb_mode to set the auto white
balance to a preset mode to apply a particular effect.
• The options are: off, auto, sunlight, cloudy, shade,
tungsten, fluorescent, incandescent, flash, and horizon.
The default is auto.

Exposure mode
• You can use camera.exposure_mode to set the exposure
to a preset mode to apply a particular effect.
• The options are: off, auto, night, nightpreview,
backlight, spotlight, sports, snow, beach, verylong,
fixedfps, antishake, and fireworks. The default is auto.

Internet of Things, refers to the network of interconnected devices that are embedded with sensors, software, and other technologies, enabling them to collect and exchange data over the internet.

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