Embedded Systems Introduction PowerPoint PDF

Embedded Systems Introduction to Embedded System Dr. Abdulkadir Jeilani Mohamud Email: [email protected] / [email protected] Embedded System Books Required Acquisitions Textbook Arduino (R3)...

Embedded Systems Introduction to Embedded System Dr. Abdulkadir Jeilani Mohamud Email: [email protected] / [email protected] Embedded System Books Required Acquisitions Textbook Arduino (R3)+ cable Buy: $54 Arduino IDE Rent: $40.50 EduShield (Project Book) Arduino(R3) + USB cable  Arduino IDE Download the latest Arduino IDE from http://arduino.cc/ This is the Java program used to create, write, compile and upload the embedded software. Download the latest Serial-to-USB drivers from http://www.ftdichip.com/Drivers/VCP.htm. These drivers allow for RS-232 serial communications via your computer’s USB port. Once installed, they create a virtual serial port, so the IDE is able to connect to the Arduino hardware via a physical USB cable. Project Book System A system is an arrangement in which all its unit assemble work together according to a set of rules. It can also be defined as a way of working, organizing or doing one or many tasks according to a fixed plan. For example, a watch is a time displaying system. Its components follow a set of rules to show time. If one of its parts fails, the watch will stop working. So we can say, in a system, all its subcomponents depend on each other. Embedded System As its name suggests, Embedded means something that is attached to another thing. An embedded system can be thought of as a computer hardware system having software embedded in it. An embedded system can be an independent system or it can be a part of a large system. An embedded system is a microcontroller or microprocessor based system which is designed to perform a specific task. For example, a fire alarm is an embedded system; it will sense only smoke. Definition Embedded System: any device that includes a computer but is not itself a general – purpose computer Hardware and software – part of some larger systems and expected to function without human intervention Respond, monitor, control external environment using sensors and actuators Embedded System An embedded system has three components:  It has hardware.  It has application software.  It has Real Time Operating system (RTOS) that supervises the application software and provide mechanism to let the processor run a process as per scheduling by following a plan to control the latencies. RTOS defines the way the system works. It sets the rules during the execution of application program. A small scale embedded system may not have RTOS. So we can define an embedded system as a Microcontroller based, software driven, reliable, real-time control system. Examples Personal digital assistant (PDA) Printer Cell phone Automobile: engine, brakes, dash, etc Surveillance Systems Automobiles Automobiles Characteristics of Embedded Systems Must be dependable: Reliability: R(t)= probability of system working correctly provided that is was working at t=0 Maintainability: M(d)= probability of system working correctly d time units after error occurred. Availability: probability of system working at time t Safety: no harm to be caused Security : confidential and authentic communication Characteristics of Embedded Systems Must be efficient: Energy efficient Code-size efficient (especially for systems on a chip) Run-time efficient Weight efficient Cost efficient Characteristics of Embedded Systems Many ES must meet real-time constraints: A real-time system must react to stimuli from the controlled object (or the operator) within the time interval dictated by the environment. !For real-time systems, right answers arriving too late (or even too early) are wrong. Characteristics of Embedded Systems Reactive and Real time – Many embedded systems must continually react to changes in the system's environment and must compute certain results in real time without any delay. Consider an example of a car cruise controller; it continually monitors and reacts to speed and brake sensors. It must compute acceleration or de-accelerations repeatedly within a limited time; a delayed computation can result in failure to control of the car. Advantages and Disadvantage Advantages Easily Customizable Low power consumption Low cost Enhanced performance Disadvantages High development effort Larger time to market ES – Processors Processor is the heart of an embedded system. It is the basic unit that takes inputs and produces an output after processing the data. For an embedded system designer, it is necessary to have the knowledge of both microprocessors and microcontrollers. Types of Processors Processors can be of the following categories: General Purpose Processor (GPP) o Microprocessor o Microcontroller o Embedded Processor o Digital Signal Processor o Media Processor Application Specific System Processor (ASSP) Application Specific Instruction Processors (ASIPs)  Microprocessor Vs Microcontroller Microprocessor Microcontroller Microprocessors are multitasking Single task oriented. For example, in nature. Can perform multiple a washing machine is designed tasks at a time. For example, on for washing clothes only. computer we can play music while writing text in text editor RAM, ROM, I/O Ports, and Timers RAM, ROM, I/O Ports, and Timers can be added externally and can cannot be added externally. vary in numbers. These components are to be embedded together on a chip and are fixed in numbers. Designers can decide the number Fixed number for memory or I/O of memory or I/O ports needed. makes a microcontroller ideal for a limited but specific task. External support of external Microcontrollers are lightweight memory and I/O ports makes a and cheaper than a microprocessor-based system microprocessor. heavier and costlier. External devices require more A microcontroller-based system space and their power consumes less power and takes What is embedded system The integration of: Sensors Actuators Energy conversion device Converts power to the kind needed by the controlled device. Motor, brake, pump, etc Intelligence With a system to produce More capable, versatile, and robust performance Appropriate Microcontroller Use A microcontroller is a correct tool to use when: Intelligence is required in the system. The complexity of a system is reduced when using one. The cost of the microcontroller is “less” than using discrete components to do the same job A variety of sensors and actuators must be one be integrated in the system. Communication with other devices is necessary. Concept Map “Embedded System” Example SawStop Powerful electric table saws can cut off fingers. How to prevent this? Organic bodies are conductive, and generally softer than wood. Using this knowledge can be a clue to solving the problem. Smart saw applied a small electrical signal to the blade When blade contacts skin, the signal changes The change activates the safety system. Example SawStop Controller hardware Computer (analog or digital ) Microcontroller Communication circuit Other device of UI Controller software C / C++ / Arduino IDE for many functions Assembly language for higher speed functions Why Arduino The Arduino environment has been designed to be easy to use for beginner who have no software or electronics experience. With Arduino, you can build objects that can respond to and or control light, sound, touch, and movement. Arduino has been used to create an amazing variety of things, including musical instruments, robots, light sculptures, games, interactive furniture, and even interactive clothing.