Transcript Dynamic Animation Cube Group 1 Joseph Clark Michael Alberts

Dynamic Animation Cube
Group 1
Joseph Clark
Michael Alberts
Isaiah Walker
Arnold Li
Sponsored by: Department of Electrical Engineering & Computer Science at UCF
What is the DAC?
The DAC is an array of LEDs assembled in a 16 * 16 * 16
array designed to simulate animation by producing
images in 3-dimensional space in the Red, Green, Blue
color spectrum.
Specifications
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Cube size:
Visible sides:
Light Emitting Diode type:
Pixel resolution:
Case construction:
Communication:
Working temperature:
Working Humidity:
Working Voltage:
Number of animations:
3.5 x 3.5 x 4 ft (L x W x H)
5 sides
RGB
16 x 16 x 16 = 4096
Transparent acrylic
USB/ SD card controller
50-104 F
10-80%
AC 110V-230V
100
What hardware is required?
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48
96
54
16
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1
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1
4,096
1
Microcontroller
LED Drivers
Resistors
Capacitors
PNP transistors
UART connection
Computer power supply
DC/DC step down voltage regulator
Designed Printed Circuit board
RGB common anode LEDs
SDHC card
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What are the hardwares
functions?
Store the animations that are to be displayed.
Select the layer that is to be illuminated to display the
animation.
Provide current to the required diode to provide the
desired color.
What software is required?
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Sprite implementation program to design the animations
to be displayed on the cube.
Cube operating code.
What are the software
functions?
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Sprite implementation program:
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Take the animations designed by the sure
and write them into code that can be read by
the microcontroller.
Cube operating code:
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Take the animation code written by the sprite
implementation program and use it to display
the desired images.
How does the DAC work?
What LED driver to select?
Led Driver
Outputs
Gray
Scale
Control
Brightness
Control
TLC59711
12
16-bit
7-bit
TLC5947
24
12-bit
N/A
TLC5941
16
12-bit
6-bit
LT3754
16
12-bit
6-bit
Error
Detecti
on
Cost
Per Driver
No
$1.79
Yes
$3.53
Yes
$3.36
Yes
$6.07
What are the benefits of the
TLC5941?
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16 Channels with 6-bit Dot correction
Controlled In-Rush Current
Two Separate Error Information Circuits
12-Bit Pulse Width Modulation Grayscale
Control
• Current Accuracy
Stellaris LM3S8962
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32-bit ARM Cortex-M3 50-MHz processor core
256 KB flash and 64 KB SRAM
42 GPIOs
Bit-Banding
UART
Synchronous serial interface (SSI)
Pulse width modulation
TLC5941 LED Driver
• 1st PCB will contain the LED drivers
• Ability to arrange devices in cascade allows a single control line to
transmit data to an individual array of drivers
TLC5941 LED Driver
• 2 control lines per color
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Best way to ensure that ideal amount of frames per second
were displayed
Surface mount Vs. Dip
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Surface mount takes up significantly less space than dip
A major factor in PCB design because 48 TLCs will be
used to drive the LEDs
LED Lattice
• 5cm pitch
• This allows for the best possible viewing orientation
• If LEDs are too close together it would be impossible
to see through the cube
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Arranged in a 16 x 16 x 16 architecture
An RGB LED is actually three separate LEDs inside one
"bulb"
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One common anode, three common cathodes
Layer Select
• 2nd PCB will contain the
Stellaris
• Stellaris uses 16 GPIOs
to control which layer is
selected.
• Sends output to array of
transistors on separate
PCB
Layer Select
• 3rd PCB will contain the layer select transistors
• Transistors Receive Layer Select From MCU
• Output goes directly to layer 0 through 15
Displaying Images
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MCU sends data serially
to the array of TLC5941s
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2 input lines per color
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Other signals sent:
o Latch
o Output Enable
o Input Clock
o PWM Clock
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Displaying Images
Data received by drivers
Held in internal registers until latch signal received
Displaying Images
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Layer is selected; states of LEDs are displayed
Layer is turned off; Data is erased from the TLC
Repeat Process 16 times for one frame
Current Requirements
Maximum current draw of the LEDs is determined by assuming all LEDs in one
layer are turned on at a single instant:
o A single LED needs 20 mA of current to be in the on state
o There are 256 LEDs per layer, if all LEDs are lit that is 5.12 A drawn.
We will use a 5V computer power supply to step down to 3.3 V for the Stellaris
Minimum current:
48 mA (Stellaris) + 3 x 50 mA (LED driver) + 0 x 20mA (LEDs) =
.198 A ± 10%
Maximum current:
48 mA (Stellaris) + 3 x 50 mA (LED driver) + 256 x 20mA (LEDs) =
5.318 A ± 10%
Multiplexing
• Almost all LED cubes rely on persistence of
vision.
• An entire image is made up of 16 layers
Impractical to light up all 16 layers at once as we
would need 4000+ IO ports
• 1 Frame:
a. Layer 0 is switched on for a short duration, a
section of the image is displayed, then
switched off
b. Repeat for all 16 layers
Multiplexing
Persistence of Vision
The effect is that the image is perceived as a whole by the
viewer as long as the entire path is completed during the
visual persistence time of the human eye.
Our goal is to produce a 24 frame/second animation
One image requires:
16 layers x 24 frames /sec = 384 layer selects/sec
Almost all LED cubes rely on persistence of vision.
Pulse Width Modulation
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Without PWM the cube could only display red, green, or
blue for each LED
With PWM there are thousands of colors to choose from
This is done by adjusting the brightness of each
individual LED diode in a particular bulb
o This allows the cube to turn on multiple colors
without drawing too much current
PWM is performed by the LED drivers
Each output can have a value of 0 to 4096 because the
length of a single output from the TLC is 12 bits
Color Wheel
phase < colorWheelLength/3
r = maxBItColor x sin(π x phase / (2 *colorWheelLength/3))
g=0
b = maxBitColor x cos(π x phase / (2 *colorWheelLength/3))
phase < 2 * colorWheelLength/3
r = maxBitColor x cos(π x (phase - colorWheelLength/3) /
(2 *colorWheelLength/3))
g = maxBitColor x sin(π x (phase - colorWheelLength/3) /
(2 *colorWheelLength/3))
b=0
phase < colorWheelLength
r=0
g = maxBitColor x cos(π x (phase - 2 *colorWheelLength/3) /
(2 *colorWheelLength/3))
b = maxBitColor x sin(π x (phase - 2 *colorWheelLength/3) /
(2 *colorWheelLength/3))
red(phase) =
0 <= phase < colorWheelLength/3
red(0) = maxBitColor x sin(0)
red = 0 - no red
red(colorWheelLength/3) = maxBitColor x sin(π/2)
red = maxBitColor - max red
Animations
• The LEDs will be controlled using an
animation file
• The color and location of which LEDs will
be lit will be determined by the animation
file
• SD Card will hold the animations
• Two Types of Animation
• Sprite based
• Function based
Sprite Animations
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Sprite based animations use the concept
of sprites
A group of images are displayed in
sequence to make an animation
This is done fast enough to create the
sense of motion
They will each have a specific number of
frames and a specified frame delay
Function Animations
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Used for the more random based
animations or animations with a strict
pattern
Such as a rain animation or moving cubes
in a set pattern
They will each have a set parameters and
a duration
Creating Animations
• Sprite based animations will be created
using a standalone program that will
produce file that can be read from the SD
Card
• Function based animations will be
functions already defined and given
variables from the SD Card
Displaying Animations
Class Diagram
Interrupt Service Routine
• The cube will have one ISR
• Its only job is to read the SD Card to
display the animations
• Will simply loop through all the data on the
SD Card forever
What is the budget?
Components
Cost per piece
# of pieces
Total
LED Drivers
$3.36
48
Sampled
Microcontroller
$14.19
1
Sampled
LED
$0.14
4,300
$602.00
PCB
TBD
2
TBD
Resistors &
Capacitors
$0.10-$0.20
128
$48.49
UART
$0.76
1
Sampled
PNP
Transistors
$0.82
16
$13.12
Total
$664.10
The University of Central Florida Department of Electrical Engineering & Computer
Science has provided the group with an endowment of $1,000 for the completion of this
project.
How far are we?
What is our time line?
Obstacles
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The cube will be 16 x 16 x 16
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Size of the cube
Prototype didn't work
Stellaris MCU
Testing LEDs
Time
Problems to be solved
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Image storage
o 24 fps / (144 fpg * 2gig) = 12 sec of animation
o Use another storage medium?
o 2 gig partitions?
 How to select?
o USB to Synchronous Serial Interface (SSI)?
Questions?