Building A Local Network With LoRaWAN

October 22, 2022 by Bryan Cockfield 40 Comments

At its core, the Internet is really just a bunch of computers networked together. There’s no reason that there can’t be other separate networks of computers, or that we all have to tie every computer we have to The One Internet To Rule Them All. In fact, for a lot of embedded systems, it doesn’t make much sense to give them a full network stack and Cat6e Ethernet just to report a few details about themselves. Enter LoRaWAN, a wireless LAN that uses extremely low power for Internet-of-Things devices, and an implementation of one of these networks in an urban environment.

The core of the build is the LoRaWAN gateway which sits at the top of a tall building to maximize the wireless range of all of the other devices. It’s running ChirpStack on the software side and uses a Kerlink Wigrid station to broadcast. The reported range is a little over 9 km with this setup. Other gateways can also be added, and the individual LoRa modules can report to any available gateway. From there, the gateways all communicate back to the central server and the information can be sent out to the wider network, Internet or otherwise.

The project’s creator [mihai.cuciuc] notes that this sort of solution might not be best for everyone. There are other wide area networks available, but using LoRaWAN like this would be likely to scale better as more and more devices are added to the network. For some other ways that LoRa can be used to great effect, take a look at this project which builds an off-grid communications network with it.

A person sits on a couch in the background wearing a VR headset. A keyboard is on their lap and a backpack studded with antennas and cables sits in the foreground.

2022 Cyberdeck Contest: Cyberpack VR

September 25, 2022 by Navarre Bartz 4 Comments

Feeling confined by the “traditional” cyberdeck form factor, [adam] decided to build something a little bigger with his Cyberpack VR. If you’ve ever dreamed of being a WiFi-equipped porcupine, then this is the cyberdeck you’ve been waiting for.

Craving the upgradability and utility of a desktop in a more portable format, [adam] took an old commuter backpack and squeezed in a Windows 11 PC, Raspberry Pi, multiple wifi networks, an ergonomic keyboard, a Quest VR headset, and enough antennas to attract the attention of the FCC. The abundance of network hardware is due to [adam]’s “new interest: a deeper understanding of wifi, and control of my own home network even if my teenage kids become hackers.”

The Quest is setup to run multiple virtual displays via Immersed, and you can relax on the couch while leaving the bag on the floor nearby with the extra long umbilical. One of the neat details of this build is repurposing the bag’s external helmet mount to attach the terminal unit when not in use. Other details we love are the toggle switches and really integrated look of the antenna connectors and USB ports. The way these elements are integrated into the bag makes it feel borderline organic – all the better for your cyborg chic.

For more WiFi backpacking goodness you may be interested in the Pwnton Pack. We’ve also covered other non-traditional cyberdecks including the Steampunk Cyberdeck and the Galdeano. If you have your own cyberdeck, you have until September 30th to submit it to our 2022 Cyberdeck Contest!

The Virtue Of Wires In The Age Of Wireless

April 9, 2022 by Elliot Williams 47 Comments

We ran an article this week about RS-485, a noise resistant differential serial multidrop bus architecture. (Tell me where else you’re going to read articles like that!) I’ve had my fun with RS-485 in the past, and reading this piece reminded me of those days.

You see, RS-485 lets you connect a whole slew of devices up to a single bundle of Cat5 cable, and if you combine it with the Modbus protocol, you can have them work together in a network. Dedicate a couple of those Cat5 lines to power, and it’s the perfect recipe for a home, or hackerspace, small-device network — the kind of things that you, and I, would do with WiFi and an ESP8266 today.

Wired is more reliable, has fewer moving parts, and can solve the “how do I get power to these things” problem. It’s intrinsically simpler: no radios, just serial data running as voltage over wires. But nobody likes running cable, and there’s just so much more demo code out there for an ESP solution. There’s an undeniable ease of development and cross-device compatibility with WiFi. Your devices can speak directly to a computer, or to the whole Internet. And that’s been the death of wired.

Still, some part of me admires the purpose-built simplicity and the bombproof nature of the wired bus. It feels somehow retro, but maybe I’ll break out some old Cat5 and run it around the office just for old times’ sake.

Dial Into The Internet Like It’s 1999

February 18, 2022 by Bryan Cockfield 19 Comments

Restoring classic hardware of any sort is a great hobby to have, whether it’s restoring vintage cars, tools, or even antique Apple or Commodore computers. Understanding older equipment can help improve one’s understanding of the typically more complicated modern equivalents, plus it’s just plain fun to get something old up and running again. Certainly we see more retro computing restorations around here, but one thing that we don’t typically see much of is the networking equipment that would have gotten those older computers onto the early Internet. [Retrocet] has a strong interest in that area, and his latest dial-up server really makes us feel like we’re back in the 90s.

This home networking lab is built around a Cobalt Qube 2 that was restored after it was gifted to him as a wedding present. The Qube had a cutting edge 250 MHz 64-bit processor with up to 256 MB of RAM, and shipped with a customized Linux distribution as an operating system. The latest upgrade to this build sped up the modems to work at their full 56k rates which involved the addition of a DIVA T/A ISDN terminal and some additional hardware which ensures that incoming calls to the modems are digital. Keeping the connections digital instead of analog keeps the modems from lowering their speed to 33k to handle the conversions.

Until recently, [Retrocet] was running some of the software needed for this setup in a custom virtual machine, but thanks to the full restoration of the Qube and some tweaking of the Red Hat Linux install to improve the Point-to-Point Protocol capabilities of the older system, everything is now running on the antique hardware. If you are like [Retrocet] and have a bunch of this older hardware sitting around, there are still some ISPs available that can provide you with some service.

Speaker Snitch Tattles On Privacy Leaks

December 9, 2020 by Bryan Cockfield 33 Comments

A wise senator once noted that democracy dies with thunderous applause. Similarly, it’s also how privacy dies, as we invite more and more smart devices willingly into our homes that are built by companies that don’t tend to have our best interests in mind. If you’re not willing to toss all of these admittedly useful devices out of the house but still want to keep an eye on what they’re doing, though, [Nick Bild] has a handy project that lets you keep an eye on them when they try to access the network.

The device is built on a Raspberry Pi that acts as a middle man for these devices on his home network. Any traffic they attempt to send gets sent through the Pi which sniffs the traffic via a Python script and is able to detect when they are accessing their cloud services. From there, the Pi sends an alert to an IoT Arduino connected to an LED which illuminates during the time in which the smart devices are active.

The build is an interesting one because many smart devices are known to listen in to day-to-day conversation even without speaking the code phrase (i.e. “Hey Google” etc.) and this is a great way to have some peace-of-mind that a device is inactive at any particular moment. However, it’s not a foolproof way of guaranteeing privacy, as plenty of devices might be accessing other services, and still other devices have even been known to ship with hidden hardware.

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Nerfnet Tunnels TCP/IP Over NRF24L01 Radios

December 4, 2020 by Tom Nardi 31 Comments

There’s an excellent chance you’ve already worked with the nRF24L01. These little modules are an easy and cheap way to shuffle data across a 2.4 GHz radio link at a respectable rate, making them great for remote control projects. But after seeing that others had experimenting with using these radios to transmit digital audio, [Andrew Rossignol] got to wondering if some software trickery could push the envelope even further.

The result is nerfnet, a Linux program that allows you to tunnel TCP/IP over a pair of nRF24L01 modules. The link appears as a virtual interface, meaning everything happens transparently as far as other programs are concerned. Anything that uses TCP/IP to communicate on Linux can take advantage of this low-cost link, albeit at speeds that most of us haven’t had to deal with in decades.

Though it’s not quite as bad as you might think. Latency is around 50 ms, and after some tweaks, [Andrew] has been able to squeeze almost 300 Kbps out of the link. That’s more than enough for terminal work, and some light audio and video streaming isn’t out of the question.

In terms of range, he was able to maintain a fairly reliable connection at a distance of up to 60 meters (200 feet) outdoors. It might not sound like much, but again, you’ve got to take the cost of these radios into account. If you’re looking to SSH into a Raspberry Pi weather station you’ve got in the backyard, a pair of these could get the job done for just a couple of bucks.

The blog post [Andrew] has put together explains the software in fantastic detail if you’re interested in the nuts and bolts of it all. But if you just want to play around with the idea, you just need to connect some nRF24L01 modules to a pair of Raspberry Pis with short SPI wires to cut down any interference, and follow the instructions. Ideally the radios would have external antennas, but it’s not strictly required.

We’ve seen these modules pushed into service as impromptu Bluetooth Low Energy transmitters in the past, but nothing quite like this. While the latency and bandwidth offered by this technique might seem antiquated to modern eyes, it could be the perfect dedicated communication channel for your sensors, smart devices, or home automation projects.

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Linux Fu: VPN For Free With SSH

November 23, 2020 by Al Williams 44 Comments

If you see a lot of banner ads on certain websites, you know that without a Virtual Private Network (VPN), hackers will quickly ravage your computer and burn down your house. Well, that seems to be what they imply. In reality, though, there are two main reasons you might want a VPN connection. You can pay for a service, of course, but if you have ssh access to a computer somewhere on the public Internet, you can set up your own VPN service for no additional cost.

The basic idea is that you connect to a remote computer on another network and it makes it look like all your network traffic is local to that network. The first case for this is to sidestep or enhance security. For example, you might want to print to a network printer without exposing that printer to the public Internet. While you are at the coffee shop you can VPN to your network and print just like you were a meter away from the printer at your desk. Your traffic on the shop’s WiFi will also be encrypted.

The second reason is to hide your location from snooping. For example, if you like watching the BBC videos but you live in Ecuador, you might want to VPN to a network in the UK so the videos are not blocked. If your local authorities monitor and censor your Internet, you might also want your traffic coming from somewhere else.

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