ECE 477Digital Systems Senior Design ProjectFall 2008

Homework 4: Packaging Specifications and Design

Due: Friday, September 26, at NOON

Team Code Name: Touch Control Group No. 4

Team Member Completing This Homework: Daniel Hum

e-mail Address of Team Member: dhum @ purdue.edu

Evaluation:

SCORE

/

DESCRIPTION

10 /

Excellent – among the best papers submitted for this assignment. Very few corrections needed for version submitted in Final Report.

9 /

Very good – all requirements aptly met. Minor additions/corrections needed for version submitted in Final Report.

8 /

Good – all requirements considered and addressed. Several noteworthy additions/corrections needed for version submitted in Final Report.

7 /

Average – all requirements basically met, but some revisions in content should be made for the version submitted in the Final Report.

6 /

Marginal – all requirements met at a nominal level. Significant revisions in 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.

1.0Introduction

Before proceeding, please read Appendix D for important information regarding recent changes made to the Touch Control.

The Touch Control is a remote control utilizing pattern recognition through multi-touch technology. It is able to interpret patterns drawn by one or more human fingers as commands to control home appliances and entertainment devices. The Touch Control is a minimalistic single-unit device, having only 1 physical button to toggle power on and off – all other device functions can be accessed through the top surface which the user draws on. The Touch Control could be sitting on a tabletop or be carried in one hand of a user, and as such should not be too bulky.

2.0Commercial Product Packaging

The Touch Control acts as a remote control for home appliances and entertainment device. Therefore, two commercial household controllers would be analyzed – the SmartLabs Design ControLinc and the SmartLabs Design RemoteLinc Wireless Remote Control.

2.1Product #1 – SmartLabs Design ControLinc

Figure 2.1.1 – Picure of the ControLinc [1]

The ControLinc is tabletop controller that controls home appliances using the INSTEON protocol [1]. It has a stand that enables it to sit on a tabletop with its main component slanted such that the control buttons faces diagonally upwards, towards the user. This makes it easy for the user to see and press the buttons from his or her upper body position, which is slightly elevated relative to the device. The ControLinc is also reasonably compact (5.0" H x 6.4" W x 3.0" D) [2] and so does not take up much space on the table.

The Touch Control does not need to be, like the ControLinc, tilted towards the user as thanks to its pattern-based touch-screen interface, the user does not need to look too carefully at where and what he is pressing. Comfort should also not be an issue since drawing on a flat surface is definitely comfortable enough, much like how one writes and draws on paper on a flat, level tabletop. The Touch Control should however learn from the fact that the ControLinc has a small footprint and so does not take up much space on a table. This is beneficial so that the device is not obtrusive.

2.2Product #2 – SmartLabs Design RemoteLinc Wireless Remote Control

Figure 2.2.1 – Picture of the RemoteLinc [3]

The RemoteLinc is a wireless remote control that controls home appliances using the INSTEON protocol. It is a handheld device, and so is small enough to fit in the user’s hand (5 3/8" H x 2 1/2" W x 1 1/8" D) [4]. It is also suitable for one-handed operation, and being wireless can be easily moved and carried around for convenience. It also features a soft-touch sueded finish for improved grip and comfort [3], which is useful since the user has to pick it up and carry it in his hand to use it.

The Touch Control unfortunately cannot be as compact as the RemoteLinc, as that would mean its touch-screen would be overly small, making it hard for the user to draw patterns on. While it would technically still be possible for the user to draw patterns on a small screen, the Touch Control strives for making drawing on it as easy and as natural as possible. It would be even tougher for one handed operation of the Touch Control while carrying it in the same hand, as that leaves the user only with his or her thumb to draw patterns with. However, the Touch Control can benefit from the RemoteLinc’s idea of using a surface finishing that improves grip. The exact material that the Touch Control would use would be suitable not just for improving the user’s grip on it, but also for improving the Touch Control’s grip on the surface that it may be sitting on.

3.0Project Packaging Specifications

The Touch Control will provide a large enough surface for the user to comfortably draw on, while at the same time will be compact enough such that it can be easily picked up and held in one hand, and also have a footprint small enough that it is not obtrusive when placed on a tabletop. It would also have a 1” strip on one edge of the touch-surface that is not touch-sensitive – this is to provide space for the user to get a good grip of the device. Lastly, it would have a rubber finishing all around expect for the touch-screen area.

The packaging will be broken up into two parts – its top surface separated from the rest of the housing, and they will be secured together by using tiny screws. For reference, the top of the device is the side with the touch-interface, and its left side is where the previously mentioned 1” strip is.The touch-screen and LCD modules will be attached to the top surface, while mostother electronic components will be on a single PCB that will be attached to the bottom portion.

The touch-screen and LCD panel are virtually flat, leaving the LCD backlight component the constraining factor for the top cover. The backlight will require 1” of height. The PCB will be screwed into the bottom of the device to prevent it from moving about. This will require that the bottom panel of the device provide tube-like stands that will elevate the PCB slightly, preventing damage to its underside, and also providing screw holes. The only other components not on the PCB are the battery and the battery charger. They would be placed on the right of the PCB, to minimize discomfort to the user since the battery may get warm, and by being placed on the right side it is away from the previously mentioned grip strip.

The touch-interface area will be 5” x 5”, and the device’s height will be 2” to give ample room for all the components. Including the aforementioned 1” grip strip, the Touch Control’s overall dimensions are 6” L x 5” W x 2” H. The power switch and power connector for the battery charger would be placed on the bottom left corner of the right side of the device. Due to the scope of this project, the wireless feature will not be implemented and instead some LEDs will be manipulated to demonstrate the functionality of the device. For this, the PWM output connector will be included next to the power switch.

4.0PCB Footprint Layout

The major components to be on the PCB are the Analog Devices Blackfin DSP chip, Cypress TrueTouch capacitive touchscreen controller and Analog Devices analog-to-digital (ATD) converter. The selected Polymer Li-Ion battery is 1.18” wide [5], leaving the maximum area for the PCB to be 4.82” x 5” which does not give much room for the other components, and so space should be saved wherever possible.

The packaging chosen for the DSP chip was the LQFP primarily because its other option, BGA, is highly unfavorable for attaching to the PCB. Also, the LQFP packaging is reasonably small sized at 26mm x 26mm and so is not a major issue. The touchscreen controller does not provide any options, with only 1 packaging being the 8mm x 8mm QFN packaging [6]. Finally, for the ATD the TQFP packaging was chosen for its smaller size (12mm x 10mm vs. 13.45mm x 10.20mm) [7].

5.0Summary

The Touch Control is designed for easy pattern drawing by providing the user with a reasonably sized touch area to draw on. It is also designed for both tabletop and handheld use, and has a rubber material covering most of it for improved traction between it and its surroundings. In addition, there is a strip of non-touch sensitive surface on its top to help the user grip the device. The Touch Control is also small and light enough that it can be picked up using one hand. It has been designed to meet all of its possible usage scenarios.

List of References

[1]INSTEON, “SmartLabs Design INSTEON ControLinc”, 2008. [Online]. Available: [Accessed: Sept. 25, 2008]

[2]Smarthome, “INSTEON ControLinc Tabletop Controller”, 2008. [Online]. Available: [Accessed: Sept. 25, 2008]

[3]INSTEON, “SmartLabs Design RemoteLinc Wireless Remote Control”, 2008. [Online]. Available: [Accessed: Sept. 25, 2008]

[4]Smarthome, “INSTEON RemoteLinc Wireless Remote Control”, 2008. [Online]. Available: [Accessed: Sept. 25, 2008]

[5]All-Battery.com, “Polymer Li-Ion Battery, 3.7V 430mAh(033048)”, 2008. [Online]. Available: [Accessed: Sept. 25, 2008]

[6]Cypress Semiconductor, “Multi-Touch Gesture”, 2008. [Online]. Available: [Accessed: Sept. 25, 2008]

[7]Analog Devices, “ADV7170/ADV7170”, 2008. [Online]. Available: [Accessed: Sept. 25, 2008]

Appendix A: Project Packaging Illustrations

Place all of your project packaging CAD drawings in this appendix.

Appendix B: Project Packaging Specifications

Part / Manufacturer/Distributor / Weight (est.) / Cost (est.)
6” x 5” x 2” Plastic Casing / Click Fold Plastics / 113 g / $10
10" x 9" x .006" Natural Latex Rubber Sheet / Small Parts, Inc. / 28 g / $1.75
5.7” LCD Panel / EarthLCD / 136 g / $59
Polymer Li-Ion Battery / All-Battery.com / 11 g / $5.95
Polymer Li-Ion Battery Charger / Sparkfun / 10 g / $16.95
Total / 298 g / $93.65

Figure B.1 – List of Materials Weight and Cost

Tooling Requirements:

-Screw driver

-Soldering tools

-Scissors

Appendix C: PCB Footprint Layout

Paste a to-scale PCB Footprint Layout (top copper), illustrating the footprint choices and relative location of the major components chosen (based on Homework #3) in this appendix.

Appendix D: Project Changes Since Homework 3

Since homework 3, there has been a design decision change to move towards using a capacitive multi-touch screen. This new development came after it was discovered that Cypress provided capacitive multi-touch screen solutions. Although Cypress was contacted immediately for more information and quotes, a reply has yet to be received. Nonetheless, the decision was made that large efforts will be made to ensure that the capacitive multi-touch screen solution is obtained, and so this report was written with that in mind.

The main change, other than the multi-touch screen implementation, is that the device has been redesigned to give allowance for handheld use. This involved making the device smaller and wireless.

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