Transcript Presentation 6 - Design Review - Purdue College of Engineering

ECE 477 Design Review
Team 2  Spring 2010
Digi-Brush
Josh Long
Katie Schremser
Caleb Ayew-ew
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
• Child’s toy that can eliminate the mess and stress
of children painting.
• User can use multiple colors by mixing 8 given
colors
• Current color will be indicated through an LED in
the tip of the brush
• Painting will be recognized by interaction with a
15” touch screen
• Image on the display can be saved onto an SD
Card
Project-Specific Success Criteria
1. An ability to display images on the display board
2. An ability to track the digital brush on the
display board
3. An ability to mimic paintbrush stroke
characteristics on the display board
4. An ability to save the painted image on a SD card
5. An ability to distinguish user’s color selection
and display selected color before being painted
Block Diagram
Microcontroller :
Freescale 9S12DP512DGV1
• 16-bit CPU (HCS12)
• 512 kB Flash EEPROM (Program Memory)
• Multiple Peripherals
– 3 SPI (FPGA)
– 2 8-channel, 10-bit ATD (Color pots, Touch Screen,
Force Resistor)
– 1 IIC (LED Driver)
• Max Frequency of 50 MHz (with
external oscillator)
• 5V Operation
FPGA:
Cyclone II EP2C20Q240C8 K ABB9Y0737A
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4 PLLs
239,616 total RAM bits
26 Embedded Multipliers
3.3V , Max 260 MHz Operation
Easily Accessible
VHDL Libraries
• Low Cost
15” Touch Monitor/Touch Screen
• 15” Size
– Comparable to an 8.5” x 11” piece of paper
– Cheaper than 12.1” for both parts combined
• 15” Touch Monitor
– Separate Monitor and Touch Screen were cheaper
than a pre-packaged touch screen
• 15” 5-Wire Resistive Touch Screen
– Resistive technology allows recognition by items
other than fingers
– 5-Wire allows more accuracy than 4-Wire
Packaging Design
8 Color pots
1 “Water” Pot
Save/Clear Buttons
Brush Holder/Connector
15” LCD Monitor
15” Touch Screen
Theory of Operation
• Power
• Microcontroller
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LED Driver
Color Pots
Force Resistor
Touch Panel
• FPGA
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Boot Chip
SDRAM
VDAC/Monitor
SD Card Reader
Theory of Operation: Power
• 31V @ 2.4A inputs to linear regulators from a
wall-wart
• Three LM350 Linear Regulators
– >=28V to:
• 1.25V
• 3.3V
• 5V
Theory of Operation:
Power Schematic
Theory of Operation: Microcontroller
External Device
Protocol (No. Pins)
FPGA
SPI (4)
GPIO (4)
Color Pots
ATD (1 each * 9 = 9)
Force Resistor
ATD (1)
LED Driver
IIC (2)
Touch Screen
ATD (1)
GPIO (4)
• 50 MHz External
Oscillator
• 2 GPIO for Save and
Clear Screen
Pushbuttons
• 5V Vdd
Theory of Operation:
Microcontroller Schematic
LED Driver
Theory of Operation: FPGA
• 50 MHz External
Oscillator
• 133 MHz External
Oscillator
• 1.25V Internal
• 3.3V Vdd
– Level Translator between
FPGA and
Microcontroller
External Device
Protocol (No. Pins)
Microcontroller
SPI (4)
GPIO (4)
SD Card Reader
SPI (4)
VDAC
Parallel Bus (33)
SDRAM
Data Bus (16)
I/O (24)
Boot Chip
Digital I/O (5)
Theory of Operation:
FPGA Schematic
VDAC, Boot Chip, Level Translator
SDRAM
PCB Layout: Considerations
• Separation of Analog and Digital
• Large Traces for Power and GND
– Copper Pour for GND
• Many Decoupling Capacitors
• Valid Trace Placements
• Room for Expansion (Headers) if needed
PCB Layout: Overall
PCB: Power Supply
PCB: µC, LED Driver, Oscillator, and
Level Translator
PCB: FPGA
PCB: VDAC, Boot Chip
PCB: SDRAM
Software Design/Development Status
• Functional Proof of Concept for mixing colors
created using Java
• Programming Microcontroller with Freescale
CodeWarrior and P&E BDM Multilink
– Using to simulate interrupts and simple programs
relevant to the project
• Have access to SPI, VDAC, and SDRAM VHDL
Libraries for the FPGA
Project Completion Timeline
Questions / Discussion