A persistent of vision display that is able online poker paypal receive images viskon to display in a two dimensional grid. The purpose of this project is to design and to create a persistence of vision POV display. This display will allow users to upload an image to be displayed through wireless communication. A persistence of vision POV refers to the phenomenon of the human eye in which an afterimage exists for a brief time 10 ms. A POV display exploits this phenomena by spinning a one dimensional row of LED's through a two dimensional space at such a disolay frequency that a persistenve dimensional display is visible. In our case, we created a cylindrical display by spinning a column of LED's around a central motor shaft Figure 1.
Clicker 4 for STM Ready Ready Board. Clicker 2 Clicker 2 for FT90x.
Persistence of vision - Wikipedia
PIC 2. PIC Capacitive. STM32F2 Cap. STM32F7 Cap. PIC32 MX7. PIC EasyStart. PIC 18FJ. GLCD Designer. GLCD Developer. AWS Home. Easy Start Kit - The more robust our hardware becomes i. The more robust we make our software i. The only case where our decisions about which hardware we used affected software decisions was when we ran into memory issues in RAM when the resolution of our display grew too large.
On our microcontroller, the ATmega, in order to increase the resolution of the display i. We decided against this due to time and space constraints on the arm itself.
The wires are the following:. The IEEE This regulation can be found in Title 47 part 15 section on the FCC regulations website. Our project does not include any existing patents, copyrights, or trademarks. We've designed all the hardware from scratch and all the software is our display work with some assistance from classmates and Professor Land.
There are two main electrical designs to this project, the onboard attached to spinning arm system and the stationary system. The primary purpose of the onboard is to actually turn on and displzy the LED's based on a two dimensional matrix further described in spinning software section. The spinhing circuit consists of spinnlng ATmega Figure 2 microcontroller which is powered by a 9V battery also onboard.
The master, the microcontroller, vjsion communicate to the slave chips via the SPI bus. It will send serial commands to write the registers on the MAX chips. On the slave end, the target MAX chip will receive an 4-bit value that it will correspond to a PWM duty cycle outputting on specific port connected to a spinnnig LED.
The max chips are powered by a 3V3 regulator from the 5V rail from the microcontroller and the LED's will be powered from that rail as well. Also, the onboard microcontroller will be calculating the RPM Rotations per Minute at every rotation to adjust the display depending on how fast the arm is spinning. Lastly, the onboard microcontroller will communicate with the stationary microcontroller via radio units.
The SPI control bus comes from the microcontroller master and chooses which MAX chip slave to talk with and control pin outputs. Since we persistence 14 LED's needing 42 driver pinsvision decided to use 5 MAX chips corresponding viion 50 outputseach with its own chip select. To collect the RPM data needed for our timing calculations, we have the microcontroller connected to an infrared IR circuit perzistence.
This circuit consists of an IR transmitter and receiver which face downwards.
Each time the circuit board passes by the white piece of paper, it will send a signal to the microcontroller to trigger an interrupt to calculate the rotation period. All of the power needed by the electrical components not including the microcontroller is from the VCC from the microcontroller.
In order to allow the microcontroller to provide enough current to power all 14 LEDs, 5 MAX chips, IR circuit, and wireless transceiver, we have a high current 1A LM linear regulator on the microcontroller to limit the 9V from the battery to 5V. Furthermore, since the MAX chips take 3.
The primary function of the stationary circuit is to act as the user interface so that the user can upload whatever image to be displayed Vision 4. Another function of the stationary circuit is to select different functions for the onboard board to perform such as animations, clearing the display, etc.
Since our motor is an AC motor that spins at 1, RPM as soon as it is plugged into the wall socket, this is too fast for our application. Thus, to reduce the speed and to prevent the motor from going from 0 to 1, RPM instantly, we are using a variable AC adapter. It is actually bision light dimmer from Lutron Electronicsbut it is essentially a variable AC, and it has a dial off choosing how much amplitude we want to spiinning to the motor.
This allowed us to perform safer tests, persistence worrying about pieces flying off of the spinning arm. The main components of our hardware design is an AC motor, a mounting bracket for the motor, and display spinning arm which is comprised of a Plexiglas piece and a plastic piece. The Plexiglas acts as the main support for the arm and is connected to the spinning shaft of the motor, while the plastic piece has for the 90 degree bend at one end to apinning a platform for mounting the LED's.
Our AC motor does not have any self-supporting component to stand upright. Thus, we have built a mounting bracket that will hold to make sure the motor is standing upright. The bracket consists of the base piece and the vertical support piece. The vertical support piece is connected to the base piece at a 90 degree angle with two size screws.
Next, the motor is attached to the vertical support piece with four size screws in a spinning orientation. The four tapped screw sockets on the motor was initially already there, so we had to just drill four holes in the vertical support that are lined up with the provided sockets on the motor.
This mounting bracket provides great stability while the motor is spinning at high rates. Load balancing of the spinning cantilever is the main reason for the stability during spinning. As an addition precautionthe user should clamped the bracket to a table during the spinning. This shaft is approximately a size N hole with a small flat edge.
In order to secure the Plexiglas firmly to the shaft without it sliding along the shaft in any way, we drilled a hole size that is just a bit smaller than size Viison to make it a very tight fitand drilled a small vision on the side to insert a set screw vision will push against the flat edge. We decided to use Plexiglas because it is a strong yet light material.
Lastly, a thin plastic piece was bent at 90 degrees near one end and attached to the Plexiglas. We are using this plastic piece mostly because it is easily bendable while also light. In order to make visiin we don't get too much wobbling when spinning at high rates, we positioned the electrical components on the spinning arm to provide good counterbalance on both sides Figure 5.
The software design of this project is relatively persisrence. We are running three tasks; task1 to record and calculate the current RPM at every revolution, task2 to write the appropriate data based on matrix to the respective MAX chip port via SPI, and task3 to run the animations. The frequency of task2 being executed depends on the measured RPM values by setting the release and deadline to the amount of time per "segment" each column in our matrix.
Each "pixel" of the image is represented by one element in the matrix. Currently, we persistence a 14x90 matrix displaying only on half of a circle, but it is possible to expand the resolution in the future. Furthermore, each element in the matrix is a 16 bit number where the first 4 bits are for the red value, the next 4 are for the green value, display the last 4 bits are for the blue value of an LED.
These 4 bit values are mapped to 8 bit values to actually set the intensity level of the LED's. The main difficulty of the software was to setup the SPI communication between the microcontroller and persistence MAX chips. Each port is controlled by registers onboard the chip. The SPI bus is used to communicate with the MAX and set spinning the explicit registers which control the ports and the implicit registers which control the state of the chip power up sequences, shutdown sppinning, run modes, etc.
To program the chip, we send commands to the register to allow maximum current draw through each pin 20ma and set displwy port high LED's are wired low logic. In order to display anything, a transmitter display send pixels to the onboard receiver which will then populate the display matrix in the microcontroller with the sent pixels.
Thus, there are two components: the transmitter code and the receiver code. The transmitter code is very straightforward; we transmit each pixel at a time as a packet. After these 2 bytes are sent, we send the column and row byte. Next, we break the 16 bit data into 3 bytes that contain the first 3 nibbles of the 16 bit data and send them across.
Lastly, we send an antisync byte to let the receiver know that pwrsistence has finished sending spinning.
The code for the receiver is a bit more complicated. After all the data bytes and the antisync byte are received, the state persistenve will proceed to recompile the individual bytes back to a 16 bit data and put it in the matrix element at the received row and column. We have also added animations to our project.
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As of now, our animation code remains to be hardcoded and a possible extension for this project can be a more user-interactive animation. The structural components of the design were very straightforward; we needed a design that would allow the motor to stand upright instead of lying down. Thus, we eventually came up with the L shaped mounting structure.
The actually machining process for this piece took time since neither my partner nor I have had much machining practice. However, it was spinninng a matter of drilling two holes through the vertical plate which lined up with the two holes in the base plate. Main article: Newton disc.
Richard Griffin and Company. Retrieved 29 October — via Google Books. Chapman and Hall. Longmans, Green.
Community project: Digital Poi Spinning – Persistence of Vision Display
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Persistent Vision Display - ECE
A history of pre-cinema. Mark 29 October American Philosophical Society. Transactions of the American Philosophical Society. JSTOR Cambridge University Press. William Innys at the West-End of St. Account of an optical deception. Explanation of an optical deception in the appearance of the spokes of a wheel when seen through visoin apertures.
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Persistence-of-Vision Display - Northwestern Mechatronics Wiki
On the Zoetrope and its Antecedents. I, Trans.Mar 20, · Overview. A fully customizable display using the concept of Persistence of Vision was created as a final project for ME in User-specified images (and even moving images) were displayed by rotating a column of LEDs at speeds faster than rpm. Each individual LED was modeled as a row of pixels. A persistence of vision (POV) refers to the phenomenon of the human eye in which an afterimage exists for a brief time (10 ms). A POV display exploits this phenomena by spinning a one dimensional row of LED's through a two dimensional space at such a high frequency that a two dimensional display . Nov 10, · This is a video of an LED based Persistence of Vision device that writes words or patterns as it is spun at night. It works like Poi Spinning but with Digita.
New York, W. Michael Taylor. Chicago: University of Chicago Press. Journal of Film and Video. This article's use of external links may not follow Wikipedia's policies or guidelines. Please improve this article by removing excessive or inappropriate external links, and converting useful links where appropriate into footnote references.
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