Homework 3: Design Constraint Analysis and Component Selection Rationale Due: Friday, February 6, at NOON

Size: px

Start display at page:

Download "Homework 3: Design Constraint Analysis and Component Selection Rationale Due: Friday, February 6, at NOON"

Randell Gerald Gardner
6 years ago
Views:

1 Homework 3: Design Constraint Analysis and Component Selection Rationale Due: Friday, February 6, at NOON Team Code Name: The_Magic_Wand Group No. 5 Team Member Completing This Homework: Michelle Zhang Address of Team Member: purdue.edu NOTE: This is the first in a series of four professional component homework assignments, each of which is to be completed by one team member. The body of the report should be 3-5 pages, not including this cover page, references, attachments or appendices. Evaluation: SCORE DESCRIPTION Excellent among the best papers submitted for this assignment. Very few 10 corrections needed for version submitted in Final Report. Very good all requirements aptly met. Minor additions/corrections needed for 9 version submitted in Final Report. Good all requirements considered and addressed. Several noteworthy 8 additions/corrections needed for version submitted in Final Report. Average all requirements basically met, but some revisions in content should 7 be made for the version submitted in the Final Report. Marginal all requirements met at a nominal level. Significant revisions in 6 content should be made for the version submitted in the Final Report. Below the passing threshold major revisions required to meet report * requirements at a nominal level. Revise and resubmit. * Resubmissions are due within one week of the date of return, and will be awarded a score of 6 provided all report requirements have been met at a nominal level. Comments: Comments from the grader will be inserted here.

2 1.0 Introduction Brief description of design project, with a focus on design constraint issues. Practical writing device that recognizes hand gestures (pen strokes) and interpret them as characters. For many years handwriting has been a dull and tedious process with little technological advancement. Team 5 looks to change this pattern with a revolutionary new product, the Magic Wand, a writing device that interprets your pen strokes and outputs the corresponding characters to a display. There are many design constraints that arise while attempting to change the hand writing landscape. The pen must contain all the required hardware for functionality while also operating off of a battery for a long enough period of time to be practical and useful. The pen must also be rugged enough to hold up to the normal wear and tear a writing device receives (drops, moisture, temperature, chewing, etc). Many of these challenges can be engineered out by choosing a proper housing for the pen electronics, but the operational requirements demand a careful choice of component selection and usage. 2.0 Design Constraint Analysis Introduce the major design constraints that will be considered in this report. Small enough hardware, enough power for all the peripherals on pen. Make sure we can have a reasonable distance between the pen and the base station. (larger the better) Accelerometer Run off battery, have orthogonal acceleration detection, proper form factor. 2.1 Computation Requirements Outline the computational tasks that your device needs to perform, and identify any real-time constraints associated with them. receive accelerometer data and transmit wirelessly and analyze accelerometer data to determine characters. 2.2 Interface Requirements Describe the general-purpose I/O functions that your device needs to perform, and identify the number of input/output pins required. Include PLDs that might be necessary to expand I/O -1-

3 capability (e.g., serial shift register) or provide support for some other I/O function (e.g., 7-segment display decoder). Also, identify any voltage/current constraints associated with each I/O signal (voltage swing required, current sourcing/sinking requirements, need for optical isolation, etc.). 16 bit for LCD (may use a shift register for data lines) Accelerometer : 2 data pins for X and Y direction. 3-5V supply, Quiescent Supply Current = 1.1mA max, PWM output = 1 KHz 1 pin for push button 6-8 pins for charger 8 pins for battery life monitor 4-8 pins for wireless module 2.3 On-Chip Peripheral Requirements Identify the on-chip peripherals required and the number of channels each peripheral needs to support (e.g., 2 channels of 10-bit ATD, 4 channels of 8-bit PWM, 2 channels of RS-232 serial I/O, 3 input capture timer channels, 2 output compare timer channels, SPI, I2C, Ethernet, etc.). SPI or 2-3 ATD Possibly SPI for LCD SPI for transceiver Accelerometer Input Capture Compare 2.4 Off-Chip Peripheral Requirements Identify any off-chip peripherals that your device requires (analog-to-digital converter, CODEC, digital-to-analog converter, keypad encoder, DTMF encoder/decoder, etc.). 2.5 Power Constraints Describe any constraints associated with power consumption/dissipation (e.g., battery powered, A.C. powered with battery backup, A.C. powered only, heat dissipation constraints due to operating environment and/or physical size of package). Battery powered pen and plug in base station Accelerometer :3-5V Quiescent Supply Current = 1.1mA 2.6 Packaging Constraints -2-

4 Describe any packaging-related constraints based on the intended application (e.g., needs to be small enough to be worn on a wrist, needs to mount in a standard 1-U rack space, needs to be made of material tough enough to withstand use by Liberal Arts majors, etc.). Small enough to write with, droppable 2.7 Cost Constraints Describe any cost-related constraints for your device (e.g., will be competing with Product X that currently has an MSRP of $99). Wii controller $40 w/o batteries Advanced pen $ Component Selection Rationale Describe the rationale for component selection, including a detailed comparison of at least two candidates for each major component choice. Discuss how the design constraints, outlined in the previous section, have driven or guided your component choices. There are four major constraints when selecting the LCD Display. Compare to 2 lines display unit, 4 lines of display unit has a better expandability for the functionality of showing casted spell images if decided to add at later stage. A backlight is neccesary for better night time visibility. It is helpful for implementation to have a thorough datasheet and reliable customer support. The price factor is also a major concern due to the limited budget. Both candidates listed meet the criteria. LCD16X4BL manufactured by Futurlec is chosen for its lower unit price. Manufacturer LCD16x4BL Futurlec Size 16X4 16X4 Backlight Yes Yes Datasheet Yes Yes Interface Parallel Parallel Price $12.90 $27.66 LCM-S01604DSF Lumex Opto/Components Inc 4.0 Summary Briefly summarize the contents of this report. -3-

5 List of References [1] Reference1 [2] Reference2 [3] Reference3 IMPORTANT: Use standard IEEE format for references, and CITE ALL REFERENCES listed in the body of your report. -4-

6 ECE 477 Digital Systems Senior Design Project Fall2008 Appendix A: Parts List Spreadsheet Vendor Manufacturer Part No. Description Unit Cost Qty Total Cost Digi-Key Freescale 9S12NE64 16-bit microcontroller $14.90 TOTAL $???.?? -5-

7 ECE 477 Digital Systems Senior Design Project Fall2008 Appendix B: Updated Block Diagram Insert an updated version of your block diagram here. The primary purpose of doing this is to give the grader a frame of reference for grading the rest of the assignment. Although no points are awarded for the block diagram, points will be taken off your score if what is written in your report is not consistent with the block diagram. Including the block diagram will also assist you with writing such sections as the interface requirements and off-chip peripherals, and more important aids the grader in understanding that what has been written is appropriate to your project. -6-

Homework 6: Printed Circuit Board Layout Design Narrative Due: Friday, February 27, at NOON

Homework 6: Printed Circuit Board Layout Design Narrative Due: Friday, February 27, at NOON Team Code Name: _Magic Wand Group No. 5 Team Member Completing This Homework: Michelle Zhang E-mail Address of