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EPA
Jon Persinger
Jonathan Snyder
Devon Dallmann
Henry Au-Yeung
Khushboo Verma
Hardware System diagram
12V
3.3V
Power Regulation
3.3V
1.8V
5V,
10Apeak
5V
Hardware
Debug
4x4 Test
Pin ready
interrupt
TMS4
70R1
A256
Compact Flash
Get pic
button
256k
Flash
12k
RAM
CPLD
Send data
via SPI
State
Machine
17 control
lines
Driver
Circuit
16x16
Solenoid
Array
Compact Flash
•Non-proprietary
•Has built-in controller
•Operation in PC Card
Memory Mode; FAT16
format
•Operates in 16-bit mode
Processor
•Operates 24 MHz
•256K on-chip Flash (image processing requires lots of
space)
•12k on-chip RAM
•Use of Rowley CrossWorks and CrossConnect for
programming and compiler
•Olimex Dev Board
•Open source code available for ARM7 architecture
•Use of two High End Timers (HET) for PWMs
•Built in SPI controller
•Provides enough IO for Compact Flash communication
in 16-bit mode
Controls Schematic
Driver
•Verification of Driver circuit
shown during PDR was
completed successfully.
•The addition of a dead time
circuit was necessary in order to
prevent the reverse current circuit
from shorting the supply rails.
•The layout of this circuit is
shown here.
Reverse
Current CKT
CLMN Select
CKT
CPLD
Solenoid
Drive Schematic
PCB Layout
•The PCB is a 4-layer 6.5” x 6.5” board with 2oz
copper on signal layers and 1oz on internal
layers.
•Logic and current carrying grounds are isolated
via a split ground plane.
•Power planes are split to limit the current loops
to the drive circuit per row.
•A temporary hardware debug section including
manual switches to control a 4x4 binary grid
without the processor and CPLD.
•High current traces were routed with copper
pours and planes to allow for low voltage drops.
FPGA vs CPLD
CONS
1.
2.
3.
CPLDs do not have to be reprogrammed at every
power up (they are static memory not dynamic, a
FPGA is programmed and loses its memory when the
power goes off). So we'd have to add some sort of
PROM (which Xilinx does sell and it's pretty cheap) to
program a FPGA at every power on
FPGAs are only 2.5 and 3.3 volt compatible, not 5 volt,
so we'd have to use step up and step down converters.
CPLD is 5 volt compatible
9500 series CPLDs hold their data for at least 20 years,
and reprogramable 10,000 times
PROS
1.
CPLDs cost more than FPGAs (cheapest Spartan III is
$10 and has more gates in it than the 95288, which is
$50) and have less gate space
2.
CPLDs have ALOT worse timings than FPGAs, their
setup and hold times are a lot longer, the gate delay is
longer, the pin to pin delay is longer (all by
about a magnitude of at least 10)
3.
FPGAs typically come in smaller packages than
CPLDs
4.
In a CPLD programming is restricted to function
blocks and macro cells, in an FPGA it is not (layout is
more efficient in an FPGA)
FPGA Simulation/Timing Diagram
Solenoids
•1000 turns allows for 5v operation which
will yield an RMS current of 225mA with
a peak current of 500mA as shown here
•The solenoids are constructed with
30AWG copper with a standard enamel
coating
•The inside diameter is 0.08inches with an
outer diameter of 1/4inch
•MagneLab will construct 256 coils at a
cost of $500 USD.
•Essentially no coil temperature increase,
even if left on.
RMS  I pk
Duty
0.5
 500mA
 225mA
3
3
Image Processing and Code
•
•
•
Use C++ for Image Processing instead of MATLAB
Cimg.h image processing library/Imagemagik (JPEG
images)
Algorithm for Code
•
•
•
•
•
•
•
Load BMP, JPG, PNG images etc
Obtain color map for the image
Scale the image
Use formula to calculate the intensity of each pixel
Translate intensity level evenly for the required height
levels for the pins
•
Obtain the x and y values for each pixel and store these
along with the corresponding pin heights
Code currently loads a BMP image and plots the intensity for
the pixels
•
Compiled executable code size 800KB--Too Big!
•
Customize Cimg.h, discard unused functions
Compile the C++ code using CrossWorks ARM7
Compiler to convert it into Assembly
Power
•120VAC/12VDC, 60W Adapter
•Step down converters (12V/5,3.3,1.8V)
•5V rail needs to supply 10A (50W) (Buck regulator)
•3.3V can source up to 1.5A (Buck regulator)
•1.8V rail (LDO regulator), external cap ESR is
critical
Responsibilities
•PCB—Jonathan
•CPLD/Verilog—Devon
•Processor—Jon, Henry
•Board Population—Henry, Jonathan
•Image Processing—Khushboo,
Jon
•Solenoid Housing—Jonathan
•Documentation—Everyone
•Driver Circuit—Jonathan, Henry
Milestones
Milestone I: 1st pcb board assembled and debugged;
hardware able to display image via switches; ability
to read from Compact Flash
Milestone II: 2nd pcb board assembled and debugged;
processor/code will be stand alone; first draft of
user’s manual; majority of technical reference
completed
Expo: Processor reading images from Compact Flash,
formats it, and sends to CPLD; possible extras
Costs
Total project budget:
EEF Request:
$1617.69
Outside funding:
UROP
24 Test Solenoids
Use of CNC machine in ITLL
Amount
$900
$75
FREE
Item
4 Layer PCB Revisions 1 and 2
Perf. Board
Processor (x4)
Development Kit
Custom Solenoids (x256)
Magnets (x550)
Compact flash Card 128mb
Power adapter 5V,12A
Total Cost
$200
$20
$57.64
$399
$500
$50
$15.90
$36.96
$900
Part Number
N/A
8.5”x8.5”
TMS470R1A256
TMDS-FET470R1B1M
Made by: Magnelab, Inc
Neodymium Iron Boron
CF128 (Kingston)
DTS120500U
Components for buck regulator
$200
Power Supply and control circuitry
N/A
Pin Rig – Plastic
Pin Rig – Plywood
Pin Rig – Foam Pad
Pin Rig - Plexiglass
Pin Rig – Nuts/Bolts/Spacers
$30.28
$7.49
$3.49
$1.00
$10
8lb High Density Polyethylene
3/8” x 2” x 4”
1’ x 4.5’
6.5”x6.5”
N/A
Shipping Costs, misc. and taxes
$50
Total:
$1617.69
Risks
•Processor Issues
•Acquired compiler/assembler/programmer this week
•Very limited software support
•On chip flash hard to work with
•Power converters/regulators
•Code Optimization
•Image processing may not fit into on-chip FLASH
•Magnetic Problems
•Increase solenoid spacing or
•Downsize 8x8 Array
Questions