Transcript ECE 477 Final Presentation Group ?? Fall 2004

ECE 477 Design Review
Team 8(SLOW)  Spring 2006
Outline
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Project overview
Project-specific success criteria
Block diagram
Component selection rationale
Packaging design
Schematic and theory of operation
PCB layout
Software design/development status
Project completion timeline
Questions / discussion
Project Overview
• Designing an LED panel by cascading 10 5x7 LED
dot matrices.
• A built in embedded server on the microcontroller to
edit/display text messages on the LED panel via a
website.
• Scrolling feature to display long text messages.
• Allows users to display the outdoor temperature
using a temperature sensor.
• Display current time using a highly accurate internal
clock.
Project-Specific Success Criteria
• Ability to display ASCII character strings on
an LED matrix.
• Ability to save messages and configuration
data in non-volatile memory.
• Ability to measure and display the outdoor
temperature.
• Ability to display the current time (based on
highly accurate internal clock).
• Ability to configure display and edit
messages via an embedded server.
SLOW Block Diagram
Component Selection Rationale
Microcontroller :
Must have a timer module for the clock, a ATD port for the temperature sensor, built in
ethernet controller, PWM module.
Choices :
Freescale MC9S12NE64CPV
80 pin package, 38 I/O pins and 10 input only
64K of FLASH memory
ATD ports
Timer Module
A IEEE 802.3 compliant ethernet controller
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Rabbit RCM 3750
33 I/O pins
Built in Ethernet Controller
512K of FLASH memory
We decided with the MC9S12NE64CPV as it has a low cost, easily attainable and has a
enough number of input output pins. Also, the MC9S12NE64CPV has good documentation
as compared to the Rabbit microcontroller.
Component Selection Rationale
LED Driver
Toshiba TB62708 with a 16 bit shift register and latching ability
- Low cost
- Programmable Output current from 5mA to 90mA
- Current sourcing device
We required a 12 bit shift register for our design but we could only find current sinking
ones.
ULN2003A Darlington Array
- 16 Bit package
- Sinks upto 500mA of current( our sink current came upto 105mA)
- Recommended by our TA Brian as used by him for one of his LED projects
RJ45 Jack
- Recommended by the microcontroller data sheet
Packaging Design
Considerations :
• LED’s panel is big enough and can be seen
from a distance of up to 30 feet.
• Aluminum Case
• Weight estimation : around 3.4 lbs and
mountable on a wall.
• Dimension is 17” x 4” x 3”
Packaging Design – 3D view
Packaging Design – Front
Packaging Design - Bottom
Schematic/Theory of Operation
Schematic/Theory of Operation
Schematic/Theory of Operation
Schematic/Theory of Operation
Schematic/Theory of Operation
Schematic/Theory of Operation
• Total Parts : 88
17 Capacitors
25 Resistors
1 crystal
10 Darlington transistors
10 LED displays
2 Power Regulators
1 BDM
1 Temperature Sensor
2 Diodes
3 Switches
10 LED drivers
2 Inductors
1 Microcontroller
1 RJ-45
1 Header
1 12V Power Adapter
PCB Layout – Whole Layout
PCB Layout – Top Layer
PCB Layout – Bottom Layer
PCB Layout - Microcontroller
PCB Layout - Microcontroller
PCB Layout – Power
PCB Layout – Shift Register and
transistors
PCB Layout – RJ45
Software Design/Development Status
– All programming and decoding will be done on
the Microcontroller
– Even without the PCB, MC9S12NE64
Development board can be used to write code
and test our components.
– LED matrices are driven by column therefore
making it possible to control text scrolling.
Project Completion Timeline
• Week 8 (This week) – Finalize PCB / Design Review
• Week 9 – Start Software Development / Final PCB
Modification
• Week 10 – Testing hardware / Continue Software
Development
• Week 11 – Continue Software Development / Testing
PCB Functionality
• Week 12 – Finalize Software / Debugging
• Week 13 – Packaging / Testing / Debugging
• Week 14 – Final Tweaking
• Week 15 – Documentation / Prepare for Final
Presentation
• Week 16 – Final Presentation
Questions / Discussion