Ubiquitous Computing & Internet of Things (IoT)

• Mark Weiser (1952-1999) of Xerox PARC is considered the "Father of Ubiquitous Computing."
• Ubiquitous Computing aims to provide information access anytime, anywhere.
• Pervasive Computing emphasizes the practical use of available technology.
• Ambient Intelligence focuses on communication tech in future homes/smart buildings.
• Embedded Systems are information processing systems within enclosing products.
• Embedded Software is software integrated with physical processes.
• Cyber-Physical Systems (CPS) integrate computation and physical processes, combining embedded systems with dynamic physical environments.
• The Internet of Things (IoT) involves interconnected devices (sensors, actuators, phones) using unique addressing to cooperate towards common goals.
• "Industry 4.0" exploits IoT technology for production.

Opportunities and Challenges

• Opportunities for IoT include Railways, Maritime Engineering, Mechanical Engineering, Robotics, and Civil Engineering.
• Challenges include dependability, security, confidentiality, safety, reliability, repairability, and availability.
• Mismatches between physical and cyber models pose a challenge.
• Real-time constraints, hybrid systems, the Zeno effect, and sampling are challenges.
• Efficient resource use is crucial, considering energy, run-time, code size, weight, and cost.
• Big Data implications and concurrency issues are noted.
• Heterogeneity/Compositional design and interdisciplinarity are important.

Examples and Characteristics

• Examples of Embedded Systems include digital cameras, wristwatches, MP3 players, refrigerators, washing machines, microwave ovens, and calculators.
• Characteristics involve using sensors and actuators.
• Actuators convert numbers into physical effects.
• Reactive systems continually interact with their environment.
• Systems are dedicated to specific applications.
• Systems use a dedicated user interface, requiring real-time performance.
• high availability and reliability are needed.
• Development is centered around a real-time operating system.
• Easy and diskless operation is a must.
• Peripherals connect input and output devices.
• Limited memory, low cost, and low-power consumption are typical.
• Secondary memory in computer is not needed.

Tools and Standards

• Tools include a text editor, compiler/assembler, linker, library, debugger, and simulator.
• Standards include ISO/IEC/IEEE 26531:2015 (content management) and ISO/IEC 27002 (security risk management).
• Constraints involve power, compute, network, crypto, inability to patch, authentication, range, cost, and implied trust.

Development Process

• Step 1: Ideation with brainstorming among stakeholders
• Step 2: Technical Specification (purpose, block diagram, features, environment, manufacturing).
• Step 3: Architecture design
• Step 4: Component & Design Finalization
• Step 5: Test Plan (reliability checking, hardware/software validation, production testing).
• Step 6: Design Implementation (architecture to design conversion).
• Step 7: Proof of Concept Prototype Development (issue identification).
• Step 8: Field trials (performance checks).
• Step 9: Final Product Design Tweaks (based on feedback).
• Step 10: Product Launch (certifications and documentation).

Development Environment and Platforms

• An Integrated Development Environment (IDE) combines a code editor, compiler, and debugger.
• MSP430 LAUNCHPAD (Texas Instruments): low-cost, low-power microcontroller with a fast-wake power-saving mode.
• NANODE: works like an Arduino, designed for internet-connected projects.
• PINGUINO PIC32: prototyping tool originally for art students.
• STM32 DISCOVERY (STMicroelectronics): another low-cost alternative.
• TEENSY 2.0: runs Arduino software, supports Arduino libraries/skitche.

Platform-Based Design

• A platform-based design methodology reuses available hardware and software to manage complexity.

Hardware In The Loop

• Hardware in the loop is a design information flow.

Cyber-Physical Interface: Input/Output

• Sensors are key components of the cyphy-interface.
• Sensors are designed for all physical quantities
• Sensor networks are a key element of IoT.

Sensor Types

• Common sensor types: Acceleration, Image, Biometric, Artificial eyes, Radio frequency identification (RFID), and Automotive sensors.
• A signal maps a time domain to a value domain.
• Signals can be continuous or discrete in time and value.

Signal Processing

• Sample-and-Hold Circuits process discrete sequences/streams.
• Incoming signals (continuous time domain) must be converted to the discrete time domain.
• Gibbs phenomenon is the larger difference between the square wave and its approximation at the jump discontinuities of the square wave
• Aliasing occurs when different unsampled signals share the same sampled representation.

Sampling Theorem

• The Sampling Theorem states aliasing is avoided if incoming signal frequencies are less than half the sampling frequency (fs).
• The Nyquist sampling criterion relates to avoiding aliasing.
• Analog-to-Digital Converters (ADCs) convert time-to-continuous value signals into time-to-discrete value signals.
• Flash ADCs use a large number of comparators.
• Resolution refers to the # of bits produced by an ADC
• Pipelined Converters consist of a chain of converters converting bits.
• Integrating Converters use two phases for measurement and compensate for noise.
• Folding ADCs divide the input voltage range into segments.
• Delta-sigma ADCs encode signal differences (deltas) then summed up (sigma).

Cyber-Physical Interface: Output

• Displays are a crucial area.
• Electromechanical devices (motors, etc.) influence the environment.
• Digital-to-analog converters generate a current proportional to a digital signal value.
• Pulse Width Modulation is to generate sufficient power for motors, lamps, loudspeakers, etc., analog outputs would need to be amplified in a power amplifier.

Overview of Ubiquitous Computing, IoT, and related concepts like Pervasive Computing, Ambient Intelligence, and Cyber-Physical Systems. Explores opportunities in railways, maritime, mechanical, robotics, and civil engineering, along with challenges.