Taking Membrane Switches to Scale: First Steps

Title: Taking Membrane Switches to Scale: First Steps
Source: Blog – DH Lab
URL: http://dhlab.lmc.gatech.edu/peabodyvis/taking-membrane-switches-to-scale-first-steps/

Recently my lab mate and I were fantasizing about theoryland. It’s this magical place where you go up to a whiteboard and, using your extensive domain knowledge, allow ephemeral non-toxic marker to create your dream system. But no Expo could predict the real world application’s truth: Murphy’s law. Bringing any system to life is not easy, but it’s worth it.

To take a simple keypad prototype to scale, I first followed Dr. Klein’s advice and created a simple “map” of the membrane switch layout at scale:

at-scale_rows+cols

Row and column ‘map’ for conductive traces at scale, 1×1 meters

I experimented with multiple materials for the traces:

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1. Single core copper wire (to be partially sheathed at ‘touch points’ where a row and column intersect)

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2. Slim (0.5″) copper tape with conductive adhesive

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3. Wide (1″) copper tape with conductive adhesive

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4. Slim (0.25″) conductive fabric tape

I laid them out on a 1/4” thick neoprene mat, meant to eventually serve as the ‘insulating separator’ between the two conductive trace layers.

IMG_5458

Top to bottom: 1″ copper tape, single core wire, conductive fabric tape, 0.5″ copper tape on neoprene

After testing, the 1″ copper tape won: it provides a wide conductive surface area, sticks with conductive adhesive (can be used to attach wires on the bottom), is relatively durable with repeated use, and (very importantly) stays economical at 60 meters.

The one downside is copper tape’s brittleness: it performs best on hard, flat surfaces and most likely wont allow for a fully soft, flexible quilt when picked up. Thankfully, we interact with the quilt on a flat surface. The touch mechanism can seemingly become ‘part of the table,’ allowing for a soft material on top to become ‘the quilt.’

I’ve begun putting copper tape on the printed grid:

IMG_5467

Initial layout on grid – testing copper tape (seen as columns from this angle) and fabric tape (seen as rows, left to right)

So far, the copper tape has not been working very well. I have prototyped with alligator clips, male-male wires (directly on top of the copper tape), and male-male wires in series with resistors. None have worked quite like the silver traces on plastic membranes with male-male wire. I will continue debugging and conduct more research into how to construct a working copper trace membrane keypad, such as a large version of this example.

LED Wiring

Title: LED Wiring
Source: Blog – DH Lab
URL: http://dhlab.lmc.gatech.edu/peabodyvis/led-wiring/

The LED strip has three inputs: +5V, Gnd, and data input. The data input has to come from one end of the strip, indicated by the arrows.

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The power for the strip can come from any end. The +5V needs to be connected to 5 volts power supply. The Ground needs to be connected to both, the ground from the power supply and to the ground pin in the Arduino mega. The data input needs to be connected to Arduino mega through 470 Ohms resistor.

Also the neopixel guide suggests to put 1000 microfarad capacitor in parallel with power. In this case two 4700 microfarads are being used for 10 led strips.

The resistor has been soldered to the wire and is covered by shrink tubing.20160715_141658

In order to power all 30 strips, terminal strips are used to distribute the power. The first terminal strip is connected to the power supply and is used to split the power to another three terminal strips.20160715_140816 20160715_141149_1

Each of the second terminal strips can host 11 connections. 10 are used by the LED strips and then the extra one can be used to power Arduino mega. On the terminals where the power is connected to the strip, two 4700 microfarad capacitors are placed.

The strip itself is separated into positive and negative parts.

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The neopixel guide recommends to use 20 – 60 mAmps per pixel. Since there are 900 pixels the total current should be 18 – 54 Amps. But I found that using one 10 Amps power supply is more than sufficient to power all the pixels at about 1/3 brightness. But incase that is not enough a second power supply can be connected to the main terminal strip.

Neoprene Square Cutout Stencil

Title: Neoprene Square Cutout Stencil
Source: Blog – DH Lab
URL: http://dhlab.lmc.gatech.edu/peabodyvis/neoprene-cutout-stencil/

One of the aspects of this project is to cut out 900 different 1 inch x 1 inch squares out of a neoprene sheet. The centers of these squares have to be spaced apart by exactly 3.333 cm vertically and horizontally from each other. Now, we could go about drawing out each of these squares on the neoprene itself with a sharpie and then cut them out afterwards with an X-acto knife — but this would’ve been time intensive as well as error-prone.

Thus, we decided to use Adobe Illustrator to generate a stencil that was correctly spaced out. By using the data sheet provided by the manufacturer of the LED strips, we used the values they specified to generate the stencil.

Image of Stencil v1.0 in Adobe Illustrator

Image of Stencil v1.0 in Adobe Illustrator

After having designed the stencil in Illustrator, we used a laser cutter to cut out the stencil out of plywood. Plywood was used because it was cheap and durable enough to keep its shape when we cut out the neoprene squares.

Our first prototype of the stencil turned out to be off by 0.333 cm between each square and led to the accumulation of an offset error between the LEDs. This error could not have been picked up by simply drawing on the neoprene — which could have led to wasted time and materials. Because we could easily fix this offset error in Illustrator, we had another stencil printed out within a couple of hours and didn’t lose any neoprene in the process.

Neoprene Stencil v1.0

Neoprene Stencil v1.0

Our final neoprene cutout stencil with correct dimensions is shown below:

Neoprene Stencil v2.0

Neoprene Stencil v2.0

For our final cutout stencil, we also used a thicker sheet of plywood to ensure the rigidity of our stencil as we cut the squares out of the neoprene.

The ‘Face’ of the Quilt: Fabric and Light Diffusion

Title: The ‘Face’ of the Quilt: Fabric and Light Diffusion
Source: Blog – DH Lab
URL: http://dhlab.lmc.gatech.edu/peabodyvis/the-face-of-the-quilt-fabric-and-light-diffusion/

Per the admittedly true cliché, you never get a second chance to make a first impression. We are reimagining the original look and feel of the 1800s quilt in modern fabrics and designs. In taking this route, we need to ensure that the materials we select do not necessitate diverging from Peabody’s intellectual contribution and intent. To review, a rendering of the original design is as follows:

originalPeabody

Elizabeth Peabody’s original design

Aspects to consider include:

  1. How well do the NeoPixels perform in varying light conditions? Many example projects photograph NeoPixels in the dark. Most likely, we want users to interact with the quilt in partially dim lighting. If necessary, office lighting
  2. How will we diffuse the light to create defined borders and retain clarity? In Peabody’s work, richly colored square cutouts were placed on top of a grid. Now, we seek to recreate the effect using LED lights
  3. What kind of texture do we want, visually and physically? Should the two mismatch? As a result, how can it create convey a message? (i.e. a soft and smooth texture may convey innocence and warmth and a rough texture may convey stability, trustworthiness, weight)
  4. Do we want the hardware to be felt or obscured? Pragmatism may dictate this result, but the difference may determine whether the user perceives an electronic quilt or a different device

In regards to 1. Light conditions and 2. Hardware… We can examine projects made with NeoPixels from Adafruit. The company that created our LED strips publishes many popular example projects that illuminate (heh) the power of NeoPixels:

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NeoPixel (our LEDs) glow fur scarf

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NeoPixel (our LEDs) bandolier costume

In regards to 2. Defined borders and clarity… we can take a cue from recessed LED light fixtures. Some office buildings opt for LED versus fluorescent lighting fixtures. In these cases, they may use panels of LEDs with polystyrene (PS) diffusing plates of varying thickness. A possible implementation could include a single 1 meter by 1 meter sheet of PS plastic with divisions cut between each touch location to allow for pressing. Examples of LED light fixtures include:

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Recessed LED light fixture with polystyrene (PS) square diffuser plate

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LED panel diffuser with PS plate

In regards to 3. texture… we have not decided between rough and smooth, but a possible implementation may include rough or smooth cotton fabric. Cotton is affordable, sturdy, and offers a wide range of textures. If choosing a rough fabric, it may be more difficult to find a color that is not a shade of light brown, light green, or in natural shades and block more light. Smooth fabrics tend to come in more modern colors and diffuse light more softly. Examples of fabric include:

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An example of a rough fabric; may allow less light to show through

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An example of a smooth cotton fabric; may allow more light to show through

In regards to 4. hardware salience… in meetings we have discussed how we might create the “LED sandwich.” A possible implementation is to create “troughs” for the LEDs by placing strips of foam in between each strip of LEDs. This way, the surface will feel roughly uniform, and a potential user may believe a single LED panel lies beneath. However, we may encounter issues with this approach because our neoprene is 1 millimeter thinner than our LED strips, as pictured:

led-neoprene-trough

Diagram depicting LED strips with our neoprene foam between; the strips are slightly taller than the foam we purchased

The Peabody Project’s present priority is to complete the physical product. We want to allow for interaction, say in a gallery or exhibition, and sooner than later allow anyone to learn and appreciate Elizabeth Peabody’s contributions to education and data visualization. Combinatorially we already see numerous implementations for our design, each with its own implications for the end product (financial cost, affective experience, etc.). After taking these ideas and experimenting on a small scale, we will be able to determine which path we will take for each.

Topic Modeling and Digital Humanities: Overview (1)

Title: Topic Modeling and Digital Humanities: Overview (1)
Source: Blog – DH Lab
URL: http://dhlab.lmc.gatech.edu/uncategorized/topic-modeling-and-digital-humanities-overview-1/

In this post:

  • What is a topic model?
  • UX considerations
  • Existing techniques

This will be the first post in a series of posts as we begin a new project on exploring topic modeling for the digital humanities, following the previous work of (link)TOME.

A topic model is a model of how often words occur together in a group of texts. Many other posts have been written about the definition of “topic model” in detail, in addition to detailing various algorithms.

http://journalofdigitalhumanities.org/2-1/topic-modeling-and-digital-humanities-by-david-m-blei/

http://journalofdigitalhumanities.org/2-1/what-can-topic-models-of-pmla-teach-us-by-ted-underwood-and-andrew-goldstone/

http://programminghistorian.org/lessons/topic-modeling-and-mallet

https://tedunderwood.com/2012/04/07/topic-modeling-made-just-simple-enough/

Here, I am going to highlight some challenges of viewing, exploring, and learning from topic modeling results.

UX considerations

How much information to show at once? Topic models typically have a lot of topics – which leads to information overload. How can you browse it a manner to learn something and not be overwhelmed?

How can you understand different views of the model? The results change based on number of topics specified by user. A small number means separate topics will merge, larger number means combined topics will split. Both are correct, but each occludes information.

Can you design for both a user familiar with the contents of the texts and a user who is unfamiliar? These are likely very different use cases. One will have questions in mind and one will be attempting to gain an initial understanding.

How do you design for trust? The model may or may not be misleading, or both. It’s not inherently bad if it is misleading – so long as the user recognizes that it is – and design can aid with this understanding.

What capabilities can metadata add? Many topic models disregard metadata and just use content. But if we use metadata, which might include things like author’s gender, race, regional location, and year, how else might one be able to explore the model?

How do you make the topic model a sustainable addition to existing work flows? Topic models would presumably be more useful if they are integrated into existing ways people work. This especially applies to people who may be less familiar with technical fields like computer science.

Existing techniques (some of them)

Dendrograms: A type of tree diagram emphasizing hierarchical clustering

More on the definition: https://en.wikipedia.org/wiki/Dendrogram

Use: http://blog.rolffredheim.com/2013/11/visualising-structure-in-topic-models.html

Pro: It maintains more complexity

Con: Its linear structure restricts links between topics

Network visualization

Use: https://tedunderwood.com/2012/11/11/visualizing-topic-models/

Pro: Shows some connections, nodes can be sized based on number of occurrences

Con: Topic models aren’t actually networks

PCA (Principal Component Analysis)

Explores the model into two dimensions

e.g. https://tedunderwood.files.wordpress.com/2012/11/prettierpca.jpg

Pro: Solves issue of false network diagrams

Con: Words overlap

There are many other interfaces, particularly ones specific to a given dataset. These will be the subjects of the next few blog posts.

TOME Discussion

Title: TOME Discussion
Source: Blog – DH Lab
URL: http://dhlab.lmc.gatech.edu/uncategorized/513/

Following the previous two blog posts where I looked at a few topic modeling interfaces, I’ll return to the lab here and write about TOME. These are based on image documentation of the project – not actual interaction with the program.

for_dh

Strengths:

Multiple views: One of the first things I noticed was that it combines different views onto one page. This combines the previous two interfaces I discussed – where one had too many disparate views and the other had one view, but was limited in other representations as a result. Here, the main visualization can be seen at the top and is clearly the most important since it is the largest. Underneath, which is cut off in the image, are other visualizations including prevalence, related topics, and geographic distribution. This might require scrolling, but is certainly better than a completely different page.

Sorting and filtering: There appear to be many different ways to sort and visualize the display – including by year, relevance, popularity, and within a certain group of documents. For exploratory purposes having more options is a good thing – so long as it doesn’t get overwhelming.

Limitations:

Scrolling: It always depends on how many topics there are, but it would be ideal if they could all be shown without requiring scrolling.

Searching: Less of a limitation, but more of a note on how users will vary on their needs based on how much they already know about the topic and/or sets of documents. The standard search bar is good if you already know what you’re looking for, but otherwise it is not very helpful and might cause frustration.

All Things Fabric: Testing, Printing, Pricing

Title: All Things Fabric: Testing, Printing, Pricing
Source: Blog – DH Lab
URL: http://dhlab.lmc.gatech.edu/peabodyvis/all-things-fabric-testing-printing-pricing/

Fabric Testing

As outlined in ‘Face’ of the Quilt, I am testing fabric to see how it diffuses, affects affect, and obscures or reveals hardware. I quickly tested a broad array of swatches. Their textures included felt, mid-weight cotton, a polyester-stretch mix, and lightweight linen. The colors included black, brown, grey, beige, and white. The colors are kept neutral because the background of the quilt will be similar to the original beige.

I was first intrigued by how introductory physics principles became useful: light colored or white fabrics tended to diffuse light while dark colored or black fabrics tended to absorb light and reveal the shape of the LED beneath. I demonstrate this as follows:

This gradient of felt (control for weight and texture) shows how lighter fabrics diffuse light while dark colors absorb them

In regards to the LED hue, there seemed to be less effect on the diffusion because there is a high intensity for all colors. Seen here, we see a slightly different diffusion for blue-toned colors but the diffusion remains mostly consistent:

The LED hue has less effect on diffusion due to high intensity (seen here under brown felt)

If I were to pick a personal favorite, it would be the mid-weight cotton-linen mix. The flecks and uneven texture lent it a natural, handmade feel that could be reminiscent of the 1800s quilt – while the modern cool blue light is the perfect juxtaposed touch:

Cotton-linen mix – a very natural, rough feel – juxtaposed with cool blue modern light

For a full tour of the test, we see below the collective effects of different fabric, where color had a greater effect on diffusion than texture:

 

Fabric Printing

We are investigating printing the Peabody design from an online fabric design service, Spoonflower, instead of sewing the design ourself. The former not only requires less time and money, but may also provide better presentation.

The idea is to design the topmost layer of the quilt in Illustrator exactly to scale and order the design to scale from Spoonflower. The options for the design are as follows:

  1. Orange fill on laser-cut design. This layout borrows dimensions from the stencil used to cut holes for the LEDs, such that the grid aligns exactly with where the LEDs shine through. 
  2.  Orange grid with major axis, and minor gridlines. This design is closer to the original design that Peabody envisioned.
  3.  Orange grid, thin gridlines, less major axis. This is still more similar to the original Peabody design than #1, but reduces emphasis on a divide. Due to the spacing of our LEDs, this is more likely than #2.

Though the online interface for the Peabody quilt allowed for flexibility on the grid design, we are physically constrained by the spacing of the LEDs which do not account for a major axis.

Next, I discovered that the maximum size for Spoonflower designs is about 21″, though you order fabrics in printable areas ranging from 41″ to about 52″. So, we cannot upload our design as-is. Instead, we need to upload 1 corner of the grid and repeat it in a “mirror” fashion:

Spoonflower design interface. Single corner design selected (first row on left). Shown is a mirror pattern that can be used to print a full grid.

 

Fabric Pricing

I performed a Python web scrape and export to CSV using Spoonflower’s product page to create a straightforward list of every type of fabric offered and the exact cost for our quilt (1 meter). Though, accounting for error and extra fabric, these costs may be higher.

Fabric Measure Price per Yard Price for Quilt (1m x 1m)
Basic Cotton Ultra yard $17.50 $19.14
Modern Jersey yard $26.50 $28.98
Cotton Spandex Jersey yard $26.75 $29.25
Fleece yard $27.00 $29.53
Minky yard $27.00 $29.53
Satin yard $18 $19.68
Premium Quilting Weight yd $19 $20.78
Cotton Poplin Ultra yard $20 $21.87
Poly Crepe de Chine yard $23 $25.15
Silky Faille yard $24 $26.25
Performance Knit yard $24 $26.25
Lightweight Cotton Twill yard $26 $28.43
Linen Cotton Canvas Ultra yard $27 $29.53
Organic Cotton Interlock Knit Ultra yard $27 $29.53
Organic Cotton Sateen Ultra yard $27 $29.53
Sport Lycra yard $32 $35.00
Heavy Cotton Twill yard $32 $35.00
Eco Canvas yard $32 $35.00
Faux Suede yard $34 $37.18
Silk Crepe de Chine yard $38 $41.56

Geo-tagging Atlanta

Title: Geo-tagging Atlanta
Source: CURVE
URL: http://sites.gsu.edu/curve/2016/05/31/geo-tagging-atlanta/

Re-posting this excellent item by Bryan Perry from the GSU Student Innovation Fellows’ blog.  GIS, Maps and Data Services Librarian Joe Hurley and SIFs have been geo-tagging a collection of glass plate negative photographs from the 1920s. These beautiful images provide rare glimpses into the area around the Five Points Metro Station, and are particularly noteworthy […]

Digital Scholarship Consultation

Title: Digital Scholarship Consultation
Source: CURVE
URL: http://sites.gsu.edu/curve/2017/01/09/digital-scholarship-consultation/

The Library recently hired Spencer Roberts to provide consultation and support for digital projects, research, and publication. Conveniently located in CURVE on the 2nd floor of Library South, Spencer’s office is open to faculty, students, and staff who have questions about what’s possible with digital scholarship, have ideas about digital projects, or would like support […]

Student Innovation Fellows Showcase on Feb. 15

Title: Student Innovation Fellows Showcase on Feb. 15
Source: CURVE
URL: http://sites.gsu.edu/curve/2017/02/20/student-innovation-fellows-showcase-on-feb-15/

Congratulations to Dr. Brennan Collins, students, faculty, and staff for putting on a great show on February 15 in CURVE, celebrating the work of GSU Student Innovation Fellows (SIFs). The Student Innovation Fellowship Program allows students to develop expertise and share ideas around emerging technologies and instructional innovations, with particular attention to enhancing learning and […]