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Microcontroller Interfacing Projects

Microcontroller Interfacing Projects . Microcontroller Interfacing. Microcontroller Interfacing. Microcontroller Interfacing. Microcontroller Interfacing. Microcontroller Interfacing. Microcontroller Interfacing. Student Project: PERIPHERALS AND MOTHERBOARD FOR THE BASIC STAMP. PURPOSE.

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Microcontroller Interfacing Projects

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  1. Microcontroller Interfacing Projects

  2. Microcontroller Interfacing

  3. Microcontroller Interfacing

  4. Microcontroller Interfacing

  5. Microcontroller Interfacing

  6. Microcontroller Interfacing

  7. Microcontroller Interfacing

  8. Student Project:PERIPHERALS AND MOTHERBOARD FOR THE BASIC STAMP

  9. PURPOSE • The purpose of this project is to design a set of motherboard core and peripheral modules for high-throughput applications to be implemented in grades 7 – 12 and in senior electrical engineering laboratories.

  10. Teaching OBJECTIVE 1. ELECTRICAL COMPONENT BEHAVIOR 2. ELECTRICAL ENGINEERING DESIGN STRATEGIES 3. TECHNICAL SKILLS GOALS • TO DEVELOP AN EFFICIENT ENVIRONMENT THAT WILL PRODUCE: • UNDERSTANDING OF ELECTRICAL CIRCUIT BEHAVIOR • WORKING PROTOTYPES FOR A LARGE VARIETY OF PROJECTS

  11. Requirements • Modularity • Manufacturing • Physical Packaging • Reliability

  12. Design Strategy • Use Stamp as Foundation Controller for multiple peripheral modules • Use communication between Stamps to increase complexity of a project • Create condensed packaged Motherboard/Module demo’s

  13. Foundation Controller • Output Current for I/O pins for Stamp I/II • DOS based application to interface BSI • Programming Languages • Memory Size • I/O pins • Port interface between PC/Basic Stamp

  14. Stamp Communication • Serin program command • Hardware implemented for communication process

  15. Packaging • Transport Circuit Design to PC Board • Package multiple demo’s into one overall storage unit

  16. 7-Segment Module

  17. LED Module

  18. Dipswitch Module

  19. MotherBoard/Module Demo’s FOUNDATION: BASIC STAMP II MICROCONTROLLER PERIPHERALS: DISPLAYS TRANSDUCERS STEPPERMOTORS SERVOMOTORS THERMISTORS LED’S

  20. Stamp/Module Costs • Source: Hosfelt Electronics, Inc 888-264-6464 • or 800-524-6464 • Catalog 99R customer #397M12 • page stock# item ea quan tot • 47 51-393 DIP switch w/rocker actuator $.85 20 $17.00 • 82 42-104 Solderless breadboard $10.95 10 $109.50 • 105 13-398 Minature speaker $.99 20 $19.80 • 117 25-350 3mm Red LED $.12 200 $24.00 • Tot $170.30

  21. Continued Cost Analysis • HOSFELT ELECTRONICS, INC Catalog 99B Cust #397M12 (MSU-ECE) • Page Part no quan item ea tot • 28 80-243 2 pkt #65 carbide drills $3.25 $6.50 • 28 80-247 2 pkt #53 carbide drills $3.25 $6.50 • 47 51-334 20 mercury tilt switch $.75 $15.00 • 67 7406 50 Hex inverter $.39 $19.50 • 72 42-194 8 4"X6" PC board $5.99 $47.92 • 86 21-267 100 16-pin DIP socket $.08 $8.00 • Total: $103.42

  22. Continued Cost Analysis • page stock# item ea quan • 62 AO2047-ND 9-pin D-sub connector, female $2.15 25 53.75 • 62 AO245-ND 25-pin D-sub connector, male $3.02 25 75.50 • 224 ZHB6718CT-ND H-bridge $3.76 20 75.16 • 384 KC003T-ND Minature thermistor $2.43 20 48.64 • Tot $253.05

  23. Continued Cost Analysis • page cat# item size $ea quan $tot • /cclad-s.htm S1-36G 1/16" FR4 glass epoxy • with 1 oz copper foil 3x6 $12.20 10pkg 122.00 • /chemphot.htm • KD-1G type-S Develop soln 1Gal $32.90 1 32.90 • PRSK-1G type-S Stripper 1Gal $92.45 1 92.45 • /chemetch.htm#Ferric Chloride • E-1G Ferric Chloride 1Gal $20.80 1 20.80 • FSB-500 Scotchbrite pad 12x24 $21.00 1 21.00 • /chemplat.htm • ITP-1QT Immersion Tin plate 1qt $23.80 2 47.60 • tot $336.75

  24. Continued Cost Analysis • BS1-IC BASIC stamp 1 @$30.60 ea quan 15 • tot = $459, S&H not included.

  25. Test Specification • Size Dimensions • Component Reliability • Code Functionality • Overall System Test Test Certification • Manufacturing of Printed Circuit Boards • Component Choice • Code Functionality • System Test

  26. Conclusions • Success was achieved for project implementation for grades 7 – 12 • Shortcoming: Did not construct projects of appropriate complexity for senior design electrical engineering laboratories Future Progress • Continued design and manufacturing of motherboard/peripheral module demo’s to be implemented in senior level electrical engineering laboratories

  27. Modularity for a Robotic Locomotion System

  28. Modularity of Robotic Systems • 1. Electrical modules • 2. Mechanical modules • 3. Software modules • 4. Electrical/mechanical/software modules: • a) of one type • b) of few types

  29. Case Study Approach Early Stages An exploration into the overall goal of our project where modularity is defined providing an overview into the mechanical structures and communication architecture. System & Design Analysis A detailed examination of the mechanical, electrical, and communication components of the electro-mechanical system. Future Perspective A hindsight perspective of problems encountered while elaborating on improvements for the process while providing an outlook upon the project’s future.

  30. The Early Stages Overall Goal What is the point of this project? Modularity? What is modularity?. An overview of the system architecture from a high level in order to understand the integration with lower level components. Architecture Overview

  31. Overall Goal • Investigation of modularity • Design of a component to act as a universal interface between the base unit and components • Improved wheel modular unit and base • Implementation of an efficient bus system with expansion capabilities with hardware

  32. What is Modularity? • Modular/ Modularity (adjective) • “Designed with standardized units or dimensions, as for easy assembly and repair or flexible arrangement and use.” • Application to Robotics • Easily attachable and detachable modules • Each module contains the necessary mechanical and electrical components (I.e. motors, microprocessors, etc.)

  33. Architecture Overview Servo Motor 1 Exploded View FT Chip Slave Processor Slave Processor Servo Motor 2 Master Processor • Consists of single master processor where all program instructions originate. • Independent slave processor allow for device independent calibrations. • Instructions passed from master->slave->FT639 (drives servo motors directly) Slave Processor Slave Processor

  34. System and Design Analysis An exploration of the mechanical design of: body, universal insert module, and servo motor housing. Mechanical Design An exploration of PCB design, master module, and the slave module. Electrical System Communication Controls An explanation of the communication of the overall integration system.

  35. Design Criteria Dimension Explanation Size • Small and compact to keep weight to a minimal Weight • Lightweight allows for decreased torque requirements on motors while allowing for increased mobility Functionality • Ability to be functional pliable and adaptable • Possibility to incorporate sensors • Mobility in terms of a wheel and with legs

  36. Body Design Design 1 Design 2 • Components • made entirely of plexiglass • sides are individual pieces • Problems • slightly lighter • many parts • Components • made entirely of plexiglass • each side is one single piece • Problems • heavy • a lot of manufacturing

  37. Body Design Final Design • Components • 2 sheets of 6x10x0.25” plexiglass – Manufactured using CNC machine • 12 Aluminum threaded Round Standoffs: ¼” OD, 1-1/2” length • Advantages • Light weight • less manufacturing (standoffs are off the shelf products • a total of 8 slots for modules

  38. Universal Insert Module Initial Design: Two part component

  39. Universal Insert Module • Final Conception • One piece component made of plastic or aluminum. • Easily manufactured with the use of the machine from Mechanical Engineering Dept at PSU.

  40. Servo Motor Housing • Problem • Resulting moments on servo horns • Deformation of servo horns Original Design

  41. Servo Motor Housing • Solution • Redirect moment onto a shaft made of stronger material • shafts connected to servo motors with use of gears and chains Lower Servo Unit (Driving) Upper Servo Unit (Steering) • 6-32 set screws • connects to insert module Steering Shaft connection Steering Shaft Driving Shaft Ball Bearing slot • 6-32 set screws • set steering shaft to lower unit

  42. Assembled Module • Spacers • 4 pieces • ¼” OD, 1/8” lenght • Upper servo unit • made of ABS 1.25x3x1’’ • manufactured using CNC machine • Insert Module • made of ABS • manufactured using FDM machine Servo Motors • Shafts • Drill Rods • Shafts from toy car • Lower servo unit • made of ABS 1.25x3x1’’ • manufactured using CNC machine • Wheel • taken from toy car

  43. Final Assembly Complete assembly of robot with four wheel modules inserted into the body

  44. Master Module Inputs Outputs Power Source: provides power to the micro-controller and also to the slave modules for their respective micro-controllers. Data Line Out: Utilizes a serial line sending data and individual instructions to each slave module component (i.e. such as speed, position) containing a micro-controller Data Line In: consists of a single serial line coming from each individual slave module carrying valuable data instructions from each slave (i.e. may include speed, position, error, and feedback information) Dedicated Bus System for SEND Basic Stamp II Micro- controller Dedicated Bus System for RECEIVE • 2 individual bus systems for sending and receiving data to avoid data collisions • Primary Program sequence contained within

  45. Slave Module Schematic Microcontroller Pin Assignments Pin 0 Dedicated COM to FT639 chip Pin 14 Dedicated SEND line to master Pin 15 Dedicated RECEIVE line to master • Each slave module unit is independent unit containing: FT639 servo controller chip, 1 Basic Stamp II microcontroller • 2 dedicated 5V lines (servo motors & chips) • 180 degree and 360 degree servo motor on board Courtesy of Kapil and Darnel • Each slave module unit is independent unit containing: FT639 servo controller chip, 1 Basic Stamp II microcontroller • 2 dedicated 5V lines (servo motors & chips)

  46. PCB Circuit Board Future Expansion Future Expansion Servo Power System Power System Ground RCV Line SND Line • Generated circuit board to be inserted into each module unit to allow for processing on the slave as opposed to master • Generated custom-designed PCB schematic sending NC and drill files for production • 2 layers: Top layer (red) and Bottom layer (blue) • 3 dedicated channels for power and ground • 2 dedicated I/O channels for communication with the master • 2 dedicated channels for future expansion (hardware id sequence)

  47. Communication Controls Master Module Unit ($FD) …….. ($FF) …….. Slave Module Unit (Addressed at $FF) • Addressing ($FC, $FD, $FE, $FF) • Allows for routing of information from master to appropriate slave unit • Sends data serially at 2400 baud • Allows handshaking while slave constantly pings for incoming data • Checks to see which modules are plugged in routing data and adjusting program accordingly • Flow Sequence • Master -> Slave > FT chip -> Slave -> Master Address Servo Position Completion Address

  48. Problems Encountered Manufacturing Mechanically Problem: Inability to align parts consistently on the CNC machine. Result: Not using the bearings for the wheel shaft Problem: Gear Specifications and slippage Result: Utilized two set screws and drilled into shafts but reduced torque Problem: Inability to produce high quality and tolerant parts through fusion deposition modeling (FDM). . Result: Loss tolerances upon inserting screws with high accuracy. Problem: Turning Mechanism for the wheel module unit Result: Moment still exists but is greatly reduced with spacer

  49. Problems Encountered Electrically Problem: Data loss and Collisions Result: Consolidated send and receive lines on individual bus systems and utilized improved power supply Problem: Faulty Connectors/ connections Result: Reconnecting slave unit several times until communication link established. Investigate better quality connectors. Problem: Sending data from master to slaves several times before communication sequence established Result: Integrated system works at times. Problem currently under further investigation. Problem: Data transmission Speeds Result: Utilized a 2400 baud transfer rates due to limitations imposed by the FT639 chip even though optimal transfer rate between Basic Stamps was found to be 9600 baud.

  50. The Next Generation Model • Solutions to Gear Slippage • use of metal gears to prevent stripping from screws • the use of larger gears to provide a better contact for the set screws • modifications to servo motor housing to incorporate a larger diameter size shaft Speed control with the use of encoders • Hardware ID tags • determine location of module that is plugged in relative to the body • Use of a multiplexer to control data flow • Allows for more uniform integration with the software tagging • Implementation of a Feedback System • Implementing proximity and various other sensors to create a “smart system” creating a feedback loop

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