Long Range WiFi Broadcasts Open-Source Video Conferencing

WiFi is an ubiquitous feature of the modern landscape, but due to power restrictions on most hardware alongside the high-frequency signal it’s typically fairly limited in range. This of course leads to frustration where a WiFi signal can be seen, but the connection is unreliable or slow. While most would reach for a range extender or other hardware bridge, [tak786] was able to roll out a better solution for his workplace by using a high-gain antenna and a single-board computer which gets him an amazing kilometer-wide WiFi network.

The build uses a 10 dBi antenna from TP-Link that’s rated for outdoor use and a single-board computer which acts as a sort of router. The antenna is placed at the top of a building which certainly helps with the extreme range as well. This setup doesn’t actually broadcast an open Internet connection, though. [tak786]’s employer needed a teleconferencing solution for their building, and he also created a fully open-source video conferencing solution called trango that can run on any LAN and doesn’t require an Internet connection. The WiFi setup in this build is effectively just a bonus to make the conferencing system more effective.

[tak786] is planning on releasing a whitepaper about this build shortly, but for now you can access the source code for the video conferencing system at his GitHub page. And, before anyone jumps to conclusions, apparently this is well within FCC rules as well. Some of the comments in the linked Reddit post suggest that with an amateur radio license this system could be pushed much further, too. If you need more range than a kilometer, though, it’s not too much more difficult to do once you have all the right hardware.

Teleconferencing Like It’s 1988: Connecting Vintage Hardware To Zoom

Hang up your car phone and toss that fax machine in the garbage. Even back in the late 80s it was possible to do away with these primitive technologies in favor of video conferencing, even though this technology didn’t catch on en masse until recently. In fact, Mitsubishi released a piece of video conferencing equipment called the VisiTel that can be put to use today, provided you can do a bit of work to get it to play along nicely with modern technology.

[Alex] was lucky enough to have one of these on hand, as soon as it was powered up he was able to get to work deciphering the messaging protocol of the device. To do this he showed the camera certain pictures with known properties and measured the output waveforms coming from the device, which were AM modulated over an RJ9 connection which he had changed to a 3.5 mm headphone jack.

It communicates in a series of pictures instead of sending an actual video signal, so [Alex] had a lot of work to do to properly encode and decode the stream. He goes into incredible detail on his project page about this process and is worth a read for anyone interested in signal processing. Ultimately, [Alex] was able to patch this classic piece of technology into a Zoom call and the picture quality is excellent when viewed through the lens of $399 80s technology.

We have been seeing a lot of other hacks around video conferencing in the past six months as well, such as physical mute buttons and a mirror that improves eye contact through the webcam.

Mirror Turns Webcam Into Document Camera

This is one of those so-simple-I-wish-I-invented-it hacks. Professor [Michael Peshkin] is teaching his engineering students remotely. While he has a nice second camera that he can use to transmit whatever he doodles on paper, most of his students just have the single webcam built into their laptops.

The solution is to put a mirror in front of the laptop cam, and flip the image left-to-right in software. They use Zoom, which has a mirror mode. Done.

The trick is making a nice frame. [Michael] has bent one out of wire, but suggests that a mirror compact works about as well in a pinch. It’s super important that his students can ask him questions backed up by drawings, and this reduces the startup cost to nearly nothing, making it universally useful.

[Prof. Peshkin] is not a stranger to mirror-based pedagogical hacks. Seven years ago, he showed us how to make a transparent whiteboard for video lectures, and it blew up on Hackaday. Since then, there are hundreds or thousands of Lightboards in the wild. We hope this idea catches on as well!

$5 Lets Your Documents Go Virtual

Video conferencing is nothing new, but the recent world events have made it much more mainstream than it has been in the past. Luckily, web camera technology is nothing new and most software can also show your screen. But what about your paper documents? Turns out that [John Nelson] can show you how to spend $5 for an old laptop camera module and put your documents center stage on your next Zoom, Skype or other video conferences.

This is especially good for things that would be hard to draw in real time during a conference like a quick sketch, a schematic, or as you can see in the post and the video demo below, chemical molecule diagrams.

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Two Way Mirror Improves Video Conferencing

Like everyone lately, [Matt] has been spending more time doing video conferencing lately. The problem is you naturally want to look at the screen, but that means you aren’t looking at the camera and, thus, you aren’t making eye contact. If you use a laptop, there is a relatively easy fix, although it isn’t particularly stylish. [Matt] built a black shroud out of foam board and put in two-way mirror. How does that help? Well, with the set up, you can put a very thin black web camera pointing up towards the mirror. Because the shroud is dark, you can see the screen through the mirror, but the camera sees you.

Where do you get a thin black web camera? You make one from an old laptop camera. They are tiny and easy to repurpose, a trick [Matt] has shared before. As a bonus, the post shows an easy way to take an LED strip and make a diffused light for lighting up your webcam call.

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