WhirlyGIG

Description: This project employs a technique similar to existing products, allowing for the continuous display of text using a high-speed rotor and a strip of LEDs. The term "WhirlyGig" is derived from the word "whirl," which means to spin, and the acronym "GIG," representing Graphical Information Gyro. The WhirlyGIG is an electronic display constructed with just eight LEDs. These LEDs rotate at a relatively high speed at the end of a rotor and flash specific patterns at precise time intervals. To the viewer, it resembles a curved LED matrix sign with scrolling text. The sign has a full 360-degree viewing angle, but there is a specific point where new text appears while old text disappears. The display message is fully programmable, utilizing a PIC16F84 microcontroller. The original program design allowed for a 256-character message to be hard-coded into the PIC's program memory. Subsequent versions enable continuous communication with a computer via a simplex serial port link, allowing messages of any length to be displayed. When an intense light source is swept through the air, glowing trails can sometimes be observed. This phenomenon, where the air appears to glow after the light source has moved, is an optical illusion that relies on the persistence of vision of the viewer's retina. Generally, the human eye has a quick reaction time to light-to-dark transitions but is slower for dark-to-light transitions, creating a temporal memory effect that produces interesting visuals, particularly with bright light sources in dark conditions. A common example is drawing shapes with sparklers during celebrations. The WhirlyGIG display consists of a strip of eight ultra-bright LEDs attached to the end of an arm that rotates around a central axis. The arm has a radius of approximately 20 cm, and the LEDs always point outward, making them visible only during half of their rotation cycle. As the LEDs turn, they create text or graphical information by altering their patterns at precise intervals, controlled by software running on the PIC microcontroller. While the WhirlyGIG produces an eye-catching display, certain assumptions are inherent in the design. Firstly, it is crucial for the viewer's eyes to remain perfectly still while the display is scanning, as eye movement can distort the display. This effect is more pronounced in some individuals than others. Secondly, viewers must possess the appropriate reaction and persistence characteristics for the LEDs to appear as if they are writing in the air. Observations during exhibitions indicated that younger viewers could see the display more clearly than older individuals, who often reported seeing only eight flashing LEDs. Although significant effort was dedicated to designing the display's components, less consideration was given to their integration, leading to various issues that needed to be resolved. The display can be categorized into four main components: the base, rotor, control PCB, and LED strip. The base component consists of a metal block from a "Helping Hand" soldering aid, connected via the center of an electrical connection block to the shaft of the drive motor. The design features an inverted drive motor, ensuring that the shaft remains fixed while the housing rotates with the rotor arm and LEDs. The motor housing is affixed to the main rotor arm, which comprises a strip of PCB glued to the flange.

The WhirlyGIG's design is an innovative approach to visual display technology, leveraging the principles of persistence of vision and rapid motion to create engaging visual effects. The use of a PIC16F84 microcontroller allows for flexibility in programming and message display, enabling users to customize content dynamically. The mechanical assembly features a well-thought-out rotor mechanism that ensures stability and reliability during operation. The arrangement of the LEDs at the end of the rotor arm maximizes visibility while minimizing the impact of motion blur, enhancing the overall viewing experience. The choice of ultra-bright LEDs contributes to the display's effectiveness, ensuring that the text remains legible even in varying ambient light conditions. The integration of a serial port communication link in later versions expands the potential applications of the WhirlyGIG, making it suitable for various interactive installations and events. Overall, the WhirlyGIG serves as a striking example of how electronic components can be combined creatively to produce captivating visual displays.This project uses the similar technique to these products, however it can write a continuous stream of text using a high speed rotor and a strip of LEDs. The word WhirlyGig is derived from the word whirl meaning to spin, and the acronym GIG which stands for Graphical Information Gyro.

The WhirlyGIG is an electronic display created using just 8 LEDs. These LEDs move at a relatively high speed on the end of a rotor, and flash specific patterns at precise time intervals. To the viewer, it has the appearance of a curved LED matrix sign with scrolling text. The sign has a full 360 degrees viewing angle, but there is a point on the sign where new text appears, and old text disappears.

The sign message is fully programmable since it makes use of a PIC16F84 micro-controller. The original program design allowed a 256 character message to be Hard-Coded into the PIC`s program memory. Later versions allow the display to continually communicate with a computer via a simplex serial port link.

This allows a message of any length to be displayed. When an intense light source is swept through the air, glowing trails can sometimes be seen. The effect of the air appearing to remain glowing after the light source has moved is an optical illusion. This effect relies on the `Persistence of Vision` of the viewer`s retina (the photosensitive part of the eye).

In general, the human eye has an exceptionally quick reaction time in detecting dark to light transients, however for light to dark transients it is much slower. This causes a temporal memory effect which can produce interesting effects especially with bright light sources in dark conditions.

A common example of this is the ability to draw shapes with sparklers on bonfire night. The WhirlyGIG display comprises of a strip of 8 ultra bright LEDs attached to the end of an arm which rotates about a central axis. The arm provides a radius of approximately 20cm. The LEDs always point outwards, so they are only visible during half of their cycle. As the LEDs rotate, they produce the text or graphical information by changing their pattern at precise intervals.

This is controlled by the software running on a PIC micro-controller. Although the WhirlyGIG produces a really eye-catching display, a few assumptions have been made that are inherently part of the design. Firstly, it is important that the viewer`s eyes remain perfectly still while the display is scanning.

Eye movement causes the display to be completely corrupted. This side effect is more noticeable to some people than to others. Secondly the viewer`s eyes must have the correct reaction and persistence characteristics for the LEDs to appear to write the message in the air. When showing the display at an exhibition, people in the younger age ranges appeared to be able to see the display more clearly than older people, who often said they just saw 8 flashing LEDs spinning around.

Although a lot of time was spent designing the various components of this display, not much thought was put into how they all fit together. This approach meant there were many problems that had to be rectified as they arose. The display can be broken down into four main components, base, rotor, control PCB and LED strip. The Base component is the metal block part of a `Helping Hand` soldering aid. This is attached via the centre of an electrical connection block to the shaft of the drive motor. The arrangement used here is to have the drive motor inverted, so that the shaft is fixed, and the housing rotates with the rotor arm and LEDs.

The motor housing is attached to the main rotor arm which consists of a strip of PCB glued to the flan