Week 1 What is IoT?

Lesson 1: Definition of the IoT

Lecture 1.1 IoT Example: The Refrigerator

• Basic functions
• Add computational intelligence
• Add a network connection

lecture 1.2 IoT Devices

• 21st century car - computer-based control system enable fuel injection anti-lock braking, etc.
• Internet access gives access to external computation and data ("the cloud")
  • 1970's logistical tagging - barcode
  • 21st century logistical tagging - intelligent RFID tags

lecture 1.3 IoT Devices vs Computers

• IoT devices have a main function
• Computers execute code
• IoT vs Computers
  • computer are general-purpose
  • IoT are special-purpose

Lesson 2: Trends in the Adoption of the IoT

Lecture 2.1 Trends in the adoption of IoT

• Convergence of several trends
• Cost of Hardware has decreased
• Hardware Size
• Computational Ability
• Internet Access

Lecture 2.2 IoT is Powerful and Pervasive

• Interface to the cloud
• Networking is Powerful
• IoT is Pervasive
  • At home
  • At work
  • On your person
  • Everywhere else

Lesson 3: The Importance of the IoT in Society

Lecture 3.1 Social Benefits of IoT

• Societal Benefits
  • IoT makes life easier
  • Independence from people
• Link to the world

lecture 3.2 Risks, Privacy, and Security

• Social isolation
• Dependence on technology and infrastructure
• Privacy and Security
  1. Observation by IoT devices is pervasive
  2. Data may be used to market to you
  • Purchasing an IoT device may give the manufacturer permission to use or sell your data
  • Data may be used by insurance agencies
  • Data may not be held in a secure way

Week 2 Embedded Systems

Honey, I Programmed the Blanket

Lesson 1: Features and Constraints of Embedded Systems

Lecture 1.1 What are embedded systems?

• Computer-based systems that do not appear to be computers - complexity is hidden from the user
• Much more common than desktops or laptops
• They interact with users via simple interface
• Efficiency Rules!
• Tight Constraints
  • Manufacturing cost
  • Design cost
  • Performance
  • Power
  • Time-to-market
  • Very different from traditional software engineering

Lecture 1.2 More on embedded systems

• Application Specificity
  • Embedded sys tend to be app-specific
  • Design is focused on one app
  • Higher design efficiency is possible
• Hardware/Software Codesign
  • Hardware and software are often designed together
  • More work for designers

Lecture 1.3 Generic embedded systems structure

IoTW2L1.3.png

• IP (Intellectual Property) Core
  • An integrated circuit that performs one function
  • Cheap in high volume
  • Very useful for common tasks
  • Must interact with the microcontroller
• FPGA (Field Programmable Gate Array)
  • Hardware that can be reconfigured via RAM

Lesson 2: Components of Embedded Systems

Lecture 2.1 Components of Embedded Systems

Microcontrollers

• Integrated circuit that executes a program
  • Microcontroller vs microprocessor
    1. slower
    2. less memory,fewer features
  • connected to other hardware components
  • Sends commands and receives data
  • Needs to be programmed

Programming Microcontrollers

• Write code on a host machine
• Programming the microcontroller

Use a Programmer

• Programming hardware can be used to place program in microcontroller memory

Lecture 2.2 More on components of embedded systems

Using a Development Board

1. General Purpose Processors

   • Used for any application
   • Many features included

2. Digital signal Processors

   • Made to support DSP functions
   • Vector instructions
   • Cheaper but more limited

3. Sensors

   • Provide simple information
   • More complicated data

4. Actuators

   • Cause events to occur in the environment
   • Simple actuators
   • complex actuators

Lecture 2.3 Sensors and actuators

Lesson 3: Interacting with the Physical World

Lecture 3.1 Analogue/Digital conversion

1. Analogue to Digital Conversion

   • Converts analogue data to digital data
   • used to interface with analogue sensors

2. Digital to Analogue Conversion

   • Converts digital signals to analogue signals
   • Used to interface with analogue actuators

Lecture 3.2 Basic equipment

A development board with a microcontroller the center of most projects

• Connectors: USB, Ethernet cable, jumper wires
• Inputs: Potentiometer, Photoresistor, Keypad, Buttons
• Outputs: LEDs
• Others: Resistor, breadboard

Week 3 Hardware and Software

Lesson 1: Hardware Components

Lecture 1.1 Hardware and Software

IoT devices are a combination of hardware and software
Hardware and Software components must be designed together.
Datasheets give details of each hardware component

• Physical size
• Input/output pins
• Electrical Parameters(max current, etc.)

Lecture 1.2 Integrated Circuits

1. Size specifications for manufacturing
2. Electrical and thermal parameters

Integrated Circuits(ICs)

• A small electronic device made of a semiconductor material(Silicon,etc.)
• Chip is protected by a package
• Package has a set of pins to allow chip access

Lecture 1.3 Microcontroller Properties

Microcontroller Characteristics

Datapath Bitwidth

• Number of bits in each register
• Determines accuracy and data throughput

Input/output pins

• Need enough pins to support your app

Performance

• clock rates are slower than desktop

Other Microprocessor Features

• Timers
  • Needed for real-time app
• Analog-to-digital converters
  • Used to read input from analog sensors
• Low-power modes
  • Power saving is key
• Communication protocol support
  • Interface with other ICs
  • UART, I2C, SPI, etc

Lesson 2: Microcontrollers and Software

Lecture 2.1 Microcontroller Components

AVR ATmega2560

• 8-bit microcontroller
• Up to 16MHz
• 256KB of flash memory
• 4KB EEPROM, 8kKB SRAM
• Peripherals

Microcontroller Components

• Storage elements
  • Data stored in different components
  • Speed/Cost(area) tradeoff
• Register: stores a single value
• Several special-purpose registers, used internally
• General-purpose registers, used by the program

Storage Elements

• Register file: Stores many values

  • A set of registers; each has an address
  • Acts just like a memory
  • Extremely fast, expensive

• Instruction operands are here

  add $r3, $r2, $r1

• Can only read one or two registers at a time

• May contain ~32 registers

Memories

• Cache: Stores many values
  • Slower than a register file
  • Cheaper than a register file
  • Still fairly fast and expensive
• Data cache holds data that the program operates on
• Instruction cache holds program instructions

Main Memory

• very big: Gigabytes (Gb)
• Not in the CPU
• Connected to the CPU via system bus
• Memory access is slow

Lecture 2.2 Compilation and Interpretation

Software Translation

• Machine language: CPU instructions represented in binary
• Assembly language: CPU instructions with mnemonics
  • Easier to read
  • Like machine language
• High-level language: commonly used language(C,C++,Java)
  • Easier to use

All software must be translated into the machine language of the microcontroller.

Compilation and Interpretation

• Compilation: translate instructions once before running the code
  • C, C++, Java(partially)
  • Translation occurs only once, saves time
• Interpretation: translate instructions while code is executed
  • Basic, Java(partially)
  • Translation occurs every execution
  • Translation can adapt to runtime situation

Lecture 2.3 Python vs. C/C++

• Python is interpreted - a scripting language
• Python is easier to work with, if speed is not primary

vs.

• C and C++ are compiled
• C and C++ are more common for performance

Software Tool Chain

IoTW3L2.3.png

• Software written on a host
• Transferred to the flash memory in the microcontroller
• Tool chain is the set of tools needed to process the software

Lesson 3: Operating Systems

Lecture 3.1 Operating Systems

Operating System

• Manages other programs
  • Windows, Linux, IOS, etc.
• Allows many programs to be executed together
• Incorporates a nice user interface
• Needs processing power and memory
• Slowing down the system, makes development easier

Lecture 3.2 Task Support

Multiple Tasks

• Assume that one microcontroller is being used
• At least four different tasks must be performed
  1. Send video data: continuous while a user is connected
  2. Service motion buttons: whenever button is pressed, may last seconds
  3. Detect obstacles: continuous at all times
  4. Auto brake: whenever obstacle is detected, may last seconds
• Detect and auto brake cannot occur together
• 3 tasks may need to occur concurrently

Process/Task Support

• Main job of an OS is to support the Process(Task) Abstraction
• A process is an instantiation of a program;
  it must have access to:
  • the CPU
  • memory
  • other resources
    • I/O, ADC, timers, network, etc.
• OS must manage resources
  • Give processes fair access to the CPU
  • Give processes access to resources

Week 4 Networking and the Internet

Mobile networks prep for the Internet of Things
Security and the Internet of Things – are we repeating history?

Lesson 1: Networking Basics

Lecture 1.1 Why is Networking Needed?

• To enhance many devices
  • Cars communicating to reduce traffic
  • Online game play
  • Access media libraries
• To access data or computational power outsider of the device

Client-Server Transactions

IoTW4L1.1.png

Client-server model is very common

• Single server, one or more clients
• Server provides a service for clients
• Server manages a resource
• Server responds to requests from the client

Computer Networks: LAN

Hierarchical system of computer-based devices which communicate

• Local Area Network(LAN) - spans a building or campus(Ethernet is most common)

Computer Networks: WAN

Wide Area Network(WAN) - Internet is best example

Computer Networks: MANET

• Mobile Ad Hoc Network(MANET) - continually changing network built from wireless, mobile devices
  • Typically short-range
  • Most common for IoT devices

Lecture 1.2 WAN Structure

A small LAN

• Ethernet is a common LAN protocol
• Ethernet switch sends messages to the right input or output

A Larger LAN

• Spans a building or campus
• Smaller LANs connected by bridges which speak both LAN protocols

A Wide Area Network

• Multiple LANs connected by routers

Lecture 1.3 Networking Components(Lab Tour)

Lesson 2: Internet Protocol

Lecture 2.1 Internet Structure

Internet Structure

• Ad hoc interconnection of networks
  • Unpredictable structure
  • Can be changed by anyone at any time
• Messages travel from source to destination by hopping through networks

Internet Protocol: Solution

• Protocol software running on each host and router
• Common communication rules for all networks
• Implement protocol(set of rules)
  • governs how hosts and routers should cooperate when they transfer data from network to network
  • TCP/IP is the protocol for the global IP Internet

Lecture 2.2 Protocols

What does an Internet Protocol Do?

• Provides a naming scheme
  • An internet protocol defines a uniform format for host addresses
  • Each host(and router) is assigned at least one of these unique internet addresses

Protocol Model

• Rules that determine how computers will communicate
• CB radio protocol
  • "Over" - I am done talking
  • "Roger" - Data received
• Rules enable efficient communication

Network Protocols

• Many networking tasks to transmit and receive data
  • Routing, flow control, arbitration
• OSI divides these tasks between network abstraction layers
• Each layer has its own responsibilities
• Each layer uses different data
  • Routing requires network topology
  • Arbitration may use message priorities

Lecture 2.3 Protocol Stack

OSI Layer Concept

• Message is received at each layer and decisions are made
• Assume layer R performs routing, transmission
  • Message M is received by layer R
  • Layer R identifies a route for message M
  • Layer R ads routing information, creating M'
  • Layer R passes message M' to the next lower layer

Encapsulation

• Communication tasks are confined to one protocol layer
• Protocol stack is the implementation(usually software) of each protocol layer

Encapsulation: Transmission

• Messages start at top layer and go down
• Message decisions are made at each layer
• Relevant information is added to the message at each layer(header or footer)

Encapsulation: Reception

• Messages start at bottom later and go up
• Relevant information is stripped at each layer
• New decisions are made, if necessary

Lesson 3: Network Layers and MATNETS

Lecture 3.1 TCP/IP Application Layer

• Transmission Control Protocol(TCP), Internet Protocol(IP)
• Protocol stack used in the Internet

• TCP/UDP used at Transport layer
  • App-to-app
• IP used at network layer
  • Host-to-host
• 4 layers total, unlike OSI's 7

Application Layer

• Protocols that directly support applications
• Information is application-specific
  • Simple Mail Transfer Protocol(SMTP): email
  • Hypertext Transfer Protocol (HTTP): web
  • Line Printer Daemon(LPD): printing

HTTP response message transmitted in response to a request for a web page (GET)

Lecture 3.2 MANETs

Mobile Ad Hoc Network (MANET)

• Self-configuring network of mobil hosts/routers
• Connected by wireless links
• Often connected to a wired LAN via an Access Point
• Common for IoT devices

IoTW4L3.2.png

MANET Issues: Power Budget

• Mobil devices are power constrained
• Standard LAN protocols must be modified
• Battery is often the heaviest component

MANET Issues: Data Rate and Security

Data rate

• Wireless bandwidth is lower than wired
• Bandwidth costs power

Security

• Power is not available for complex security
• No encryption, anti-virus, etc.

Network Programming in Practice

• We write code at the application level
• Lower levels handled by library functions
• Ex:
  • SendMessage() function creates a TCP/IP message and transmits it
  • ReceiveMessage receives a TCP/IP message and returns contents

Lecture 3.3 Packet Capture Demo