Course Introduction Lecture Notes - College of Engineering, Purdue ...

Purdue IM:PACT* Fall 2016 Edition *Instruction Matters: Purdue Academic Course Transformation

Microprocessor System Design and Interfacing

ECE 362 Course Introduction https://engineering.purdue.edu/ece362

Instructor Professor Vijay Raghunathan Office: MSEE 224 Phone: 494-7392 E-mail: [email protected]

Please send all course-related correspondence to this address

Course E-mail: [email protected]

Description Introduction to (“small memory model”) control-oriented microcontroller software, hardware, and interfacing  Emphasis: basic computer engineering concepts  Not a course about “personal” or general-purpose computers, but rather about embedded microcontrollers 

Purpose To provide an introduction to microcontrollers, assembly language programming techniques, interface hardware design, embedded system design, and general computer engineering concepts  Specifically geared toward meeting core ECE curriculum requirements 

Why This Course Is Important 

Embedded microcontrollers are used extensively in process control, instrumentation, home appliances, automobiles, etc. – they represent a basic building block of modern digital systems design and the future “Internet of Things” (IoT)

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If you go into virtually any form of engineering design, there is a high probability that knowledge of embedded microcontrollers will be required

Prerequisites 

Course on high-level language programming – (Purdue equivalent: CS 159)

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Course on digital logic design – (Purdue equivalent: ECE 270)

Lab Kits/References Required NEED TO PURCHASE:  Microcontroller Kit (on-line)  DK-3 Parts Kit (on-line)  “iClicker” student response unit  Three-ring binder for notes and lab manual PROVIDED ON COURSE WEBSITE:  Numerous reference documents OPTIONAL REFERENCE TEXT: 

HCS12/9S12 - An Introduction to Software and Hardware Interfacing (2nd Ed.), Han-Way Huang, Delmar, Cengage Learning, ISBN 1435427424

Lecture Notes 

Two versions are available: – Lecture Summary Notes: intended primarily as a “skeleton reference” for following along with the lecture and taking notes during class (formatted for printing) – Class Presentation Slides: intended primarily for use as an “on screen” reference for annotating a printed copy of the Lecture Summary notes (not formatted for printing)  Posted in PDF format on the course web site (notes and slides will be progressively updated as the semester progresses)

Lab Experiments       

The lab for this course is located in room EE 056 You must consistently attend the lab division for which you have officially registered Quizzes will be given at the beginning of each lab period (starting with Lab Experiment 1) Pre-lab exercises that are assigned must be finished by the beginning of your scheduled lab Steps of experiments must be demonstrated to your lab instructor as they are completed All work for a given lab must be completed by the end of your scheduled lab period to receive credit Make-ups require an officially excused absence and pre-approval by your Lab Instructor

Homework 

Problem sets will be posted on the web site  Collected at the beginning of your scheduled lab period and returned the following week  No credit will be awarded for late homework  Your first assignment is to read the Course Policies & Procedures and Lab Policies and Procedures documents posted on the web site

Class Participation Bring your iClicker to each class meeting − a properly registered, working iClicker is required to earn class participation credit − no exceptions will be made  Attendance is required to earn class participation credit − no exceptions will be made  iClickers will be registered during class – use will begin on Friday, January 15 

Office Hours Scheduled office hours for all course staff members are posted on the course web site

We will also be using Piazza to facilitate on-line discussion

Lab Office Hours (Monday-Thursday, 7:00-10:00 PM) will start August 29

Mini-Project     

Embedded system design based on Freescale 9S12C32 Microcontroller Kit Basic requirement is to design a product that makes good use of the processor’s computational and interfacing resources Done in teams of 2-4 students (self-selected) PCB design/fabrication option available (counts for bonus credit) Design Showcase (“Spark Challenge”) participation also counts for bonus credit

Facts About Learning Design 

FACT: Very little learning occurs as a result of just listening about how to solve design problems

Facts About Learning Design 

FACT: Very little learning occurs as a result of just reading about how to solve design problems

Facts About Learning Design 

FACT: Very little learning occurs as a result of just watching someone else solve design problems

Facts About Learning Design The best way to learn design-oriented material is to put it into practice!  The best way to study for this course is to practice, practice, practice!  There are no shortcuts! 

Suggestion: Read assigned text material before lecture, and work homework problems and review for quizzes as soon after lecture as possible. Key to success: Keep current!

Learning Outcomes A student who successfully fulfills the course requirements will have demonstrated: 1. an ability to program a microcontroller to perform various tasks 2. an ability to interface a microcontroller to various devices 3. an ability to effectively utilize microcontroller peripherals 4. an ability to design and implement a microcontroller-based embedded system

Learning Objectives As part of faculty participation in the Purdue IMPACT initiative, a detailed set of learning objectives have been developed based on Bloom’s taxonomy The goal is to teach intentionally and test intentionally based on the stated outcomes and objectives A list of learning objectives is included in the Lecture Summary Notes for each outcome as well as the Class Presentation Slides

Learning Outcome Assessment  

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You will earn 1% bonus credit for each course outcome you successfully demonstrate Outcome 1 will be assessed based on scores received for the lab practical programming problems, for which a score of at least 60% on either of the two practical exams -OR- a score of at least 60% on each lab experiment will be required to demonstrate basic competency Outcomes 2 and 3 will be assessed based on lab practical concept exams, for which a score of at least 60% will be required to demonstrate basic competency Outcome 4 will be assessed based on the Embedded System Design MiniProject, for which a score of at least 60% will be required to demonstrate basic competency

90% to 100% A- / A / A+

Grade Determination

80% to 90%

B- / B / B+

70% to 80%

C- / C / C+

60% to 70%

D- / D / D+

< 60%

F

Bonus Exercises (M-P Poster, Video, Design Showcase) Class Participation (iClickers)

∆1% 5.0%

Homework Assignments (10 @ 1%)

10.0%

Lab Experiments (10 @ 2%)

20.0%

Lab Quizzes (10 @ 0.5%)

5.0%

Lab Practical Concept Assessment Exams (2 @ 15%)

30.0%

Lab Practical Programming Assessment Exams (2 @ 7.5%)

15.0%

Embedded System Design Mini-Project (Outcome 4)

15.0%

Outcome Demonstration Bonus (4 @ 1%)

∆2% 100+∆%

Grade Determination Note: There are no A / B / C / D / F “quotas”!  Goal: Minimize number of D / W / F grades!! 

Fall 2015 course GPA: 2.92

Borderline Cases and Incompletes    

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A “borderline” is officially defined as an NWP within 0.5% of a cutoff Before course grades are assigned, the instructor will carefully examine all such cases to determine if the next higher grade is warranted IMPORTANT NOTE: The “next higher grade” is NOT AUTOMATICALLY GUARANTEED!! A grade of I or E will be given only for cases in which there are documented medical or family emergencies that prevent a student from completing required course work by the end of the semester University Regulations stipulate that a student must be PASSING in order to qualify for a grade of I or E

Academic Honesty 

All cases of “cheating” will be reported to the Dean of Students Office and to the ECE Associate Head  Activities that are considered to be cheating are listed in the COURSE POLICIES AND PROCEDURES document  Resist the temptation to take short-cuts in schoolwork – they inevitably lead to shortcuts in careers!!  A professional person does not take credit for the work of someone else!

Emergency Preparedness   

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To report an emergency, call 911 To obtain updates regarding an ongoing emergency, sign up for Purdue Alert text messages, or view current status at www.purdue.edu/ea There are nearly 300 Emergency Telephones outdoors across campus and in parking garages that connect directly to the PUPD − if you feel threatened or need help, push the button and you will be connected immediately If a fire alarm sounds during class we will immediately suspend class, evacuate the building, and proceed outdoors − do not use the elevator If we are notified during class of a Shelter in Place requirement for a tornado warning, we will suspend class and shelter as directed If we are notified during class of a Shelter in Place requirement for a hazardous materials release or a civil disturbance (including a shooting or other use of weapons), we will suspend class and shelter in the classroom, shutting/securing the door and turning off the lights See the Emergency Preparedness website for additional information http://www.purdue.edu/ehps/emergency_preparedness/index.html

Important Deadlines/Restrictions     

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All lab division changes must be done through MyPurdue during the first week of classes You must attend the lab division for which you have officially registered No late pre-labs or homework will be accepted Requests for make-up labs must be approved by your Lab Instructor in advance of the evening office hour session you plan to complete the makeup Quizzes will be given at the beginning of your scheduled lab period – there will be no make-ups (quizzes missed due to officially approved absences will be pro-rated – maximum is 2) Makeup exams for planned absences on scheduled exam dates must be arranged in advance and completed during the week the exam is being administered Exams missed due to officially excused absences (illness or family emergency) will be made up during finals week

Words to the Wise Everyone currently enrolled has the potential to do well in this course  You will not do well, however, if you: 

– don’t come to class – don’t read the assignments before class – fail to do the homework problems – attempt to “cram before exams” – merely “look at” the practice exams – let your lab partner do all the work – expect to “learn by osmosis” – attempt to “cheat” in any way

Let’s Get Started!     

The first part of this course will cover assembly language and C programming techniques The second part will cover microcontroller interface design techniques The third part will cover microcontroller peripherals and application examples The fourth part will cover embedded system design considerations All of the topics covered in this course have been carefully chosen, based on how the material will be used in later courses

A LOOK INSIDE A MODERN EMBEDDED SYSTEM: THE NEST LEARNING THERMOSTAT D. G. Meyer ©2015-2016, Images Property of their Respective Owners

BACKGROUND

Nest Labs Company History • • • •

• • •

Headquartered in Palo Alto, California Designs and manufactures sensor-driven, Wi-Fi enabled, self-learning (programmable) thermostats and smoke detectors Co-founded by former Apple engineers Tony Fadell and Matt Rogers in 2010 First product was Nest Learning Thermostat (2011), inspired by Fadell’s motivation to build a better “electronic” thermostat than those currently available Google acquired Nest Labs for $3.2B early in 2014 Nest purchased Dropcam for $555M later in 2014 Latest product is Nest Protect (Smoke and Carbon Monoxide detector with voice alerts)

BACKGROUND How Nest Learns

BACKGROUND

Basic 4-Wire Circuit Thermostat Circuit Questions: 1. What is unknown? 2. What signal is (generally) not available at the thermostat? 3. What are implications of the need to switch 24VAC at up to 1 A? 4. What are implications of the unknown load impedance? 5. What are the implied restrictions on how an electronic thermostat can be powered?

PATENTS

Ease of Installation US Patent 8,523,083 (filed Jun. 2012, issued Sep. 2013) THERMOSTAT WITH SELF-CONFIGURING CONNECTIONS TO FACILITATE DO-IT-YOURSELF INSTALLATION ABSTRACT A thermostat is configured for automated compatibility with HVAC systems that are either single-HVAC-transformer systems or dualHVAC-transformer systems. The compatibility is automated in that a manual jumper installation is not required for adaptation to either single-HVACtransformer systems or dual-HVAC-transformer systems. The thermostat has a plurality of HVAC wire connectors including a first call relay wire connector, a first power return wire connector, a second call relay wire connector, and a second power return wire connector. The thermostat is configured such that if the first and second external wires have been inserted into the first and second power return wire connectors, respectively, then the first and second power return wire connectors are electrically isolated from each other. Otherwise, the first and second power return wire connectors are electrically shorted together.

PATENTS

Event Forecasting System US Patent 8,620,841 (filed Aug. 2012, issued Dec. 2013) DYNAMIC DISTRIBUTED-SENSOR THERMOSTAT NETWORK FOR FORECASTING EXTERNAL EVENTS ABSTRACT Systems and methods for forecasting events can be provided. A measurement database can store sensor measurements, each having been provided by a non-portable electronic device with a primary purpose unrelated to collecting measurements from a type of sensor that collected the measurement. A measurement set identifier can select a set of measurements. The electronic devices associated with the set of measurements can be in close geographical proximity relative to their geographical proximity to other devices. An inter-device correlator can access the set and collectively analyze the measurements. An event detector can determine whether an event occurred. An event forecaster can forecast a future event property. An alert engine can identify one or more entities to be alerted of the future event property, generate at least one alert identifying the future event property, and transmit at least one alert to the identified one or more entities.

PATENTS

Event Forecasting System

PATENTS

Advanced Energy Harvesting (“Power Stealing”) Strategy US Patent 8,511,577 (filed Aug. 2012, issued Aug. 2013) THERMOSTAT WITH POWER STEALING DELAY INTERVAL AT TRANSITIONS BETWEEN POWER STEALING STATES ABSTRACT A thermostat includes a plurality of HVAC (heating, ventilation, and air conditioning) wire connectors including a connection to at least one call relay wire. The thermostat may also include a powering circuit, including a rechargeable battery, which is configured to provide electrical power to the thermostat by power stealing from a selected call relay wire. The power stealing may include an active power stealing mode, in which power is taken from the same selected call relay wire that is used to call for an HVAC function, and an inactive power stealing mode in which, in which no active call is being made. The powering circuit may be configured to substantially suspend (or at least reduce the level of) power stealing for at least a first time period following each transition of the thermostat from between operating states.

PACKAGING DESIGN Printed Circuit Boards

PACKAGING DESIGN Subsystem Assembly

BLOCK DIAGRAMS High Level

BLOCK DIAGRAMS Microcontroller (Back Plate)

KEY FUNCTIONS

Mechanical Causation of Insertion Sensing Signals

KEY FUNCTIONS

Accommodation of Single and Dual Transformer Installations

SCHEMATIC DETAILS Connection Sensing Mechanism

Use of auto-switching connectors for automatically selecting a source for power harvesting

SCHEMATIC DETAILS Connection Sensing Mechanism

SCHEMATIC DETAILS Power Supply - 1

“high voltage” buck converter

SCHEMATIC DETAILS Power Supply - 2

Bootstrap LDO

SCHEMATIC DETAILS Power Supply - 3

Battery LDO and charging circuitry

SCHEMATIC DETAILS

Output Drive for Connection Between RC and W (or Y / G)

Why is a transformer required? Why is PWM used?

Most electronic thermostats accomplish this function (switching AC signals) using a relay or an (optically isolated) thyristor (triac or SCR) – why is such a complicated circuit used by the Nest Thermostat to perform essentially the same task?

RELIABILITY & SAFETY FEMCA* of Power MOSFETs

Questions:

1. What happens if the MOSFETs heat up (even just a few degrees above ambient)? 2. What is the most likely cause of power MOSFET failure? 3. What happens if either or both MOSFETs fail open? 4. What happens if either or both MOSFETs fail shorted? 5. What is the criticality level of either of these failure modes? *failure effects mode and criticality analysis

WANT TO LEARN MORE?

Or, analyze, design, and/or build something like this?

Take ECE 477 Digital Systems Senior Project!