Dynamic Animation Cube Group 1 Joseph Clark Michael Alberts Isaiah Walker Arnold Li

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1 Dynamic Animation Cube Group 1 Joseph Clark Michael Alberts Isaiah Walker Arnold Li Sponsored by: Department of Electrical Engineering & Computer Science at UCF

2 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.

3 Specifications Cube size: 3.5 x 3.5 x 4 ft (L x W x H) Visible sides: 5 sides Light Emitting Diode type: RGB Pixel resolution: 16 x 16 x 16 = 4096 Case construction: Transparent acrylic Communication: USB/ SD card controller Working temperature: F Working Humidity: 10-80% Working Voltage: AC 110V-230V Number of animations: 100

4 What hardware is required? Microcontroller LED Drivers Resistors Capacitors PNP transistors UART connection Computer power supply DC/DC step down voltage regulator Designed Printed Circuit board 4,096 RGB common anode LEDs 1 SDHC card

7 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.

8 What software is required? Sprite implementation program to design the animations to be displayed on the cube. Cube operating code.

9 What are the software functions? Sprite implementation program: o Take the animations designed by the sure and write them into code that can be read by the microcontroller. Cube operating code: o Take the animation code written by the sprite implementation program and use it to display the desired images.

10 How does the DAC work?

11 What LED driver to select? Led Driver Outputs Gray Scale Control Brightness Control Error Detecti on Cost Per Driver TLC bit 7-bit No $1.79 TLC bit N/A Yes $3.53 TLC bit 6-bit Yes $3.36 LT bit 6-bit Yes $6.07

12 What are the benefits of the TLC5941? 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

13 Stellaris LM3S 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

14 TLC5941 LED Driver 1 st 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

15 TLC5941 LED Driver 2 control lines per color o Best way to ensure that ideal amount of frames per second were displayed

16 Surface mount Vs. Dip 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

17 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 Arranged in a 16 x 16 x 16 architecture An RGB LED is actually three separate LEDs inside one "bulb" One common anode, three common cathodes

19 Layer Select 2 nd PCB will contain the Stellaris Stellaris uses 16 GPIOs to control which layer is selected. Sends output to array of transistors on separate PCB

20 Layer Select 3 rd PCB will contain the layer select transistors Transistors Receive Layer Select From MCU Output goes directly to layer 0 through 15

21 Displaying Images MCU sends data serially to the array of TLC5941s 2 input lines per color Other signals sent: o Latch o Output Enable o Input Clock o PWM Clock

22 Displaying Images Data received by drivers Held in internal registers until latch signal received

23 Displaying Images 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

24 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) x 20mA (LEDs) = A ± 10%

25 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 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

26 Multiplexing

27 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.

28 Pulse Width Modulation 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

29 Color Wheel

30 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))

31 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

32 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

33 Sprite Animations 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

34 Function Animations 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

35 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

36 Displaying Animations

37 Class Diagram

38 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

39 What is the budget? Components Cost per piece # of pieces Total LED Drivers $ Sampled Microcontroller $ Sampled LED $0.14 4,300 $ PCB TBD 2 TBD Resistors & Capacitors $0.10-$ $48.49 UART $ Sampled PNP Transistors $ $13.12 Total $ 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.

40 How far are we?

41 What is our time line?

42 Obstacles The cube will be 16 x 16 x 16 Size of the cube Prototype didn't work Stellaris MCU Testing LEDs Time

43 Problems to be solved 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)?

45 Questions?

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