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.
Anytime you’re having more than a handful of people over to your place for a wild rager or LAN party (or both), you’ll generally need a way to make sure everyone can get their devices on the network. Normally, this would involve either putting your WiFi password into more phones than you can count or yelling your password across a crowded room. Neither of these options suited [NicoHood] and his partner, however, so he came up with another more secure solution to the WiFi-in-a-crowded-room problem.
He calls his project “guestwlan” and it’s set up to run on a Raspberry Pi with a touch screen. When a potential WiFi user approaches the Pi and requests access to the network, the Pi displays a QR code. Within that code is all of the information that the prospective device needs to connect to the network. For those who have already spotted the new security vulnerability that this creates, [NicoHood] has his guest WiFi on a separate local network just to make sure that even if someone nefarious can access the Internet, it would be more difficult for them to do anything damaging to his local network. As it stands, though, it’s a lot more secure than some other WiFi networks we’ve seen.
[NicoHood] also released his software on Git but it has been configured for use with Arch. He says that it would probably work in a Debian environment (which the Raspberry Pi-specific OS is based on) but this is currently untested. Feel free to give it a try and let us know how it goes.
This one must have been fun to come up with because it’s got it all. There’s hardware, firmware, networking, and server scripts all working together to create a filing, scanning document center for your business. The best part is that [Janis Jakaitis] was tasked to do this as part of his job (we’re sure there’s a bunch of IT guys shaking their heads at this statement, but it sounds like fun to us!).
The goal was to use an existing document scanner to create PDFs which are then stored in a filing system on the network. Of course it needed to be automatic. The first big issue was that the scanner was USB only, and when connected to a USB-to-LAN bridge the buttons on the device no longer functioned. [Janis] put together an Arduino circuit that added that button, as well as a display to show the status of your scan job.
The next issue is getting the filing system to recognize the document as a unique file. The solution here is to generate a unique barcode label that can be affixed to the page before scanning. Since this is a standalone setup, it was tricky to get the label printer to spit out a unique label. He already had the Arduino working with the scanner, so [Janis] decided to use it to drive this barcode job as well. It calls to a Lua script running on the server, which then pushes the next unique code to the printer.
Tie it all together and you get the demo video after the break.
Continue reading “Using Your Existing Hardware To Automate Scanning And Filing”