A Brief History Of Optical Communication

We live in the information age where access to the internet is considered a fundamental human right. Exercising this right does largely rely on the technological advances made in optical communication. Using light to send information has a long history: from ancient Greece, through Claude Chappe’s semaphore towers and Alexander Graham Bell’s photophone, to fiber optic networks and future satellite internet constellations currently developed by tech giants.

Let’s dive a little bit deeper into the technologies that were used to spread information with the help of light throughout history. Continue reading “A Brief History Of Optical Communication”

Experiment With SFP Modules With This Handy Breakout

While most home networking hardware comes with network ports baked in from the factory, industrial grade gear is typically more versatile. Using standards like Small Form-factor Pluggable, or SFP, network switches can be used with a variety of transport mediums by simply swapping tranceivers in and out. These network devices typically handle the nitty gritty of transmitting Ethernet over fiber optics, and for those keen to experiment, this breakout may come in handy.

The board design comes complete with an SFP receptacle, allowing a variety of compatible receivers to be plugged in for experimentation. With the standard using differential signalling, the board carries hardware to allow the transceiver to be fed with single-ended signals instead, though a differential version is available too. The board can be used for transmitting different signals over fiber, outside just Ethernet, or used as a simple way to reprogram SFP modules via I2C. The latter can be useful to get around DRM in network switches that attempt to lock out generic transceiver modules.

It’s a useful piece of hardware for the fiber optic tinkerer and network admin alike. You might also find it useful if you’re building your own 10-gigabit network at home!

Fiber Optics, But… Wetter?

Fiber optics are a great way to transfer huge quantity of data at lightning speed. Thanks to the property of total internal reflection, which allows light to flow through a glass fiber like fluid through a pipe, they can be used for communications at long distances and form the backbone of modern communication networks. However, water is also able to pull off the total internal reflection party trick, and [Mike Kohn] decided to see if it could be used as a communication medium, too.

The experimental setup consists of an ATTiny85 that receives signals over its serial port, and outputs the received bits by flashing an LED. This LED is attached to a plastic tube filled with water. On the receiving end, another ATTiny85 reads the voltage level of a photodiode placed in the other end of the tube. When the ADC detects voltage over a certain level, it toggles a pin connected to the serial RX pin.

Hooking the setup to a pair of terminals, [Mike] was able to successfully transmit 9600 baud serial data through a tube full of water with just an LED and a small microcontroller. To verify the success, he ran the test again with an air-filled tube instead, which failed. In doing so, he proved that the water was doing the work.

We’ve seen other optical data hacks, too – like this awesome laser ethernet build. Video after the break.

Continue reading “Fiber Optics, But… Wetter?”

Fiber Optic Ceiling Pumps To The Beat

For years [Centas] dream was to take the stars to his home and build a fiber optic ceiling. Even though there are many fiber optic star ceiling kits commercially available, we are glad he decided to go full DIY on this project as the result is simply astonishing.

[Centas] chose to make a model of a section of the sky as it is visible from his home and generated a map of 1,200 stars with the planetarium software Celestia. The most time-consuming part of making a star ceiling is always poking lots of holes for the fibers. In [Cenas] case this turned out to be especially cumbersome as he decided to install the fibers after hanging the ceiling panel so he came up with a method to catch the fiber with a fishing pole after pushing it through from the bottom. The finished ceiling looks really great though with its rounded edges that contain RGB LED strips for side illumination. [Cenas] also painted the ceiling after installing the fibers so they are not visible when they are not lit but there is still enough light shining through the paint.

Continue reading “Fiber Optic Ceiling Pumps To The Beat”

Build Yourself A Set Of Glowing Wings

Humans didn’t come with wings from the factory, and most efforts to fit them after the fact have been at least as far as flight is concerned, largely fruitless. That doesn’t mean you can’t cut a devastatingly sharp aesthetic though, and [Natalina’s] fiber optic wings are a great way to do just that. 

The wings are a leathercraft project, consisting of a harness worn around the torso. This serves as the mounting point for the fiber optics, as well as the RGB Critter flashlight used to drive the lightshow. Leather parts are lasercut to the right shape, making it easy to create the delicate feather shapes in the design. The pieces are then dyed appropriately and sewn together into the final shape. Bundles of optical fibers are then wound through the harness, sprouting from either shoulder of the wearer. EVA foam is used to help create the right shape for the wings, allowing the different layers to remain separated to create more visual depth.

It’s a build that looks absolutely striking at night, and unlike some other wing-based cosplays, doesn’t have as many drawbacks as far as crowds and transportation. It would make a killer look if you’re going as a Hacker Angel for Halloween this.

Makers certainly know how to craft some cutting-edge wearables. Got your own sweet build? Throw it at the tips line!

Bumblebee Breakout, A DIY Wearable Connector

The practice of developing wearable electronics offers a lot of opportunity for new connector designs and techniques for embedding electronics. Questions like these will eventually come up: How will this PCB attach to that conductive fabric circuit reliably? What’s the best way to transition from wire to this woven conductive trim? What’s the best way to integrate this light element into this garment while still maintaining flexibility?

Mika Satomi and Hannah-Perner Wilson of Kobakant are innovators in this arena and inspire many with their prolific documentation while they ask themselves questions similar to these. Their work is always geared towards accessibility and the ability to recreate what they have designed. Their most recent documented connector is one they call the Bumblebee Breakout. It connects an SMD addressable RGB LED, such as Adafruit’s Neopixel, to a piece of side glow fiber optic 1.5mm in diameter. On a short piece of tubing, the four pads of the SMD LED are broken out into four copper rings giving it the look of a striped bumblebee. To keep from shorts occurring while wrapping the copper tape contacts around the tube, they use Kapton tape to isolate each layer as they go.

This connector was originally created to be used in a commission they did out of Koba, their e-textile tailor shop located in Berlin. Fiber optics were applied to jackets for a performance called “All Your Base Are Belong To Us” produced by the Puppetry Department of the Hochschule für Schauspielkunst Ernst Busch.

Peruse more e-textiles techniques and learn how to build a connector transitioning from an embroidered thread bus to a wire and how to knit solderable circuit boards. And make sure to click around Kobakant’s website, it’s full of e-textile DIY tutorials! 

Add Fiber-optic Control To Your CNC

CNC machines can be very noisy, and we’re not talking about the kind of noise problem that you can solve with earplugs. With all those stepper motors and drivers, potentially running at high-speed, electrical noise can often get to the point where it interferes with your control signals. This is especially true if your controller is separated from the machine by long cable runs.

But electrical noise won’t interfere with light beams! [Musti] and his fellow hackers at IRNAS decided to use commodity TOSLINK cables and transmitter / receiver gear to make a cheap and hackable fiber-optic setup. The basic idea is just to bridge between the controller board and the motor drivers with optical fiber. To make this happen, a couple of signals need to be transmitted: pulse and direction. They’ve set the system up so that it can be chained as well. Serializing the data, Manchester encoding it for transmission, and decoding it on reception is handled by CPLDs for speed and reliability.

The team has been working on this project for a while now. If you’d like some more background you can check out their original design ideas. Design files from this released version are up on GitHub. A proposed improvement is to incorporate bi-directional communications. Bi-directional comms would allow data like limit-switch status to be communicated back from the machine to the controller over fiber.

This optical interface is in service of an open-source plasma cutter design, which is pretty cool in itself. And if the IRNAS group sounds familiar to you, that may be because we recently ran a story on their ambitious gigabit ethernet-over-lightbeam project.