Network Hacks

123 Articles

MQTT And The Internet Of Conference Badges

February 18, 2020 by 6 Comments

Today, nearly every modern consumer device wants to connect to the Internet for some reason. From your garage door opener to each individual smart bulb, the Internet of Things has arrived in full force. But the same can’t be said for most of our beloved conference badges. Wanting to explore the concept a bit, [Ayan Pahwa] set out to create his own MQTT-connected badge that he’s calling CloudBadge.

As this was more of a software experiment, all of the hardware is off-the-shelf. The badge itself is an Adafruit PyBadge, which doesn’t normally have any networking capabilities, but does feature a Feather-compatible header on the back. To that [Ayan] added a AirLift FeatherWing which allows him to use the ESP32 as a co-processor. He also added a strip of NeoPixel LEDs to the lanyard, though those could certainly be left off if you’re not looking to call quite so much attention to yourself.

The rest was just a matter of software. [Ayan] came up with some code that uses the combined hardware of the PyPadge and ESP32 to connect to Adafruit.io via MQTT. Once connected, the user is able to change the name that displays on the screen and the colors of the RGB LEDs through the cloud service. If you used something like this for an actual conference badge, the concept could easily be expanded to do things like flashing the badge’s LEDs when a talk the wearer wanted to see is about to start.

The modern conference badge has come a long way from simple blinking LEDs, offering challenges that you’ll likely still be working on long after the event wraps up. Concerns over security and the challenge of maintaining the necessary infrastructure during the event usually means they don’t include networking features, but projects like CloudBadge show the idea certainly has merit.

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A Network Attached VFD Tube Clock

February 6, 2020 by 10 Comments

The elegance of Power over Ethernet (PoE) is that you can provide network connectivity and power over a single cable. Unfortunately not nearly enough hardware seems to support this capability, forcing intrepid hackers to take matters into their own hands. The latest in this line of single-cable creations is this beautiful Vacuum Fluorescent Display (VFD) clock from [Glen Akins].

Testing the VFD tube socket

One of the key advantages VFDs have over their Nixie predecessors is greatly reduced energy consumption, and after [Glen] ran the numbers, he saw that a display using six VFD tubes could easily be powered with standard PoE hardware. With this information, he started designing the PCB around the early 1990s era IV-12 tube, which has the advantage of being socketed so he could easily remove them later if necessary.

[Glen] first had to create a schematic and PCB footprint for the IV-12 tube that he could import into Eagle, which he was kind enough to share should anyone else be working with these particular tubes down the line. After a test of the newly designed socket was successful, he moved onto the rest of the electronics.

The clock is powered by a Microchip PIC18F67J60, which connects to the Ethernet network and pulls the current time down from NTP. After seeing so many clocks use an ESP to connect to the Internet over WiFi, there’s something refreshing about seeing a wired version. The tube segments are driven by a HV5812, also Microchip branded. Lastly, [Glen] used a number of DC/DC converters to generate the 1.5 V, 3.3 V, 5 V, and 25 V necessary to drive all the electronics and VFDs.

We absolutely love the simplicity of this clock, from its sleek aluminum enclosure to that single RJ45 jack on the back. But if you’re looking for something with a bit more flash, [Glen] also put together some PoE Christmas lights over the holidays which share a number of design elements with this project.

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Keeping A 3D Printed NAS Updated With The Times

January 26, 2020 by 28 Comments

Back in 2018, [Paul-Louis Ageneau] created a 3D printed network-attached storage (NAS) enclosure for his Raspberry Pi. The design worked well, the Internet liked it when he posted the details on his blog, and all was right with the world. But of course, such glories are fleeting. Two years later that design needs updating, and thanks to the parametric nature of OpenSCAD, he’s been able to refresh his design for another tour of duty.

In our book, this is as much a cautionary tale as it is a success story. On one hand, it’s a testament to the power of CAD and desktop 3D printing. That a design can be tweaked and reproduced down the line with only minimal hassle is great for folks like us. But it’s also a shame that he didn’t get more than two years before some of the parts he used in the original NAS became unobtainium.

The main issue was that the integrated USB hub he used for the first version is no longer available, so the design had to be modified to accept a similar board. Unfortunately, the new hub is quite a bit wider than the old one. Resizing the entire case isn’t really an option since the Pi has to slide into it, so the hub now bumps out a bit on one side. He’s added a printable cover that cleans it up a bit, but the asymmetrical look might be a problem for some. While fiddling with the design, he also changed around the cooling setup so a larger fan could be mounted; now that the Raspberry Pi 4 is out, it can use all the cooling help it can get.

We covered the original version of the printed NAS back when it was first released, and it’s always good to see a creator coming back and keeping a project updated; even if it’s because hardware availability forced their hand.

PoE Powers Christmas Lights, But Opens Up So Much More

December 31, 2019 by 10 Comments

Addressable LEDs are a staple of homemade Christmas decorations in our community, as is microprocessor control of those LEDs. So at first sight [Glen Akins]’ LED decorated Christmas tree looks pretty enough, but isn’t particularly unusual. But after reading his write-up you’ll discover there’s far more to the project than meets the eye, and learn a lot about the technologies behind it that has relevance far beyond a festive light show.

The decoration is powered exclusively from power-over-Ethernet, with a PIC microcontroller translating Art-Net DMX-over-Ethernet packets into commands for the LED string. The control board is designed from the ground up and includes all the PoE circuitry, and the write-up  gives a very thorough introduction to this power source that takes the reader way beyond regarding PoE as simply another off-the-shelf black box. Along the way we see all his code, as well as learn a few interesting tidbits such as the use of a pre-programmed EEPROM containing a unique MAC address.

So if your house has CAT5 wiring and you want an extra dimension to your festive splendour, you’ve officially got a whole year to build your own version. He’s featured here before, with his buzzer to break the Caps Lock habit.

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Optical Communication Using LEDs Alone

December 22, 2019 by 52 Comments

We’re all used to the humble LED as a ubiquitous source of light, but how many of us are aware that these components can also be used as photodiodes? It’s something [Giovanni Blu Mitolo] takes us through as he demonstrates a simple data link using just a pair of LEDs and a couple of Arduinos. It’s a showing off his PJON networking layer, and while you’d need a bit more than a couple of LEDs on breadboards for a real-world application, we still think it’s a neat demonstration.

PJON itself is very much worth a look, being an implementation of a robust and error-tolerant network for Arduinos and other small microcontroller platforms. It has a variety of communication strategies for various different media, and as this LED demonstration shows, its strength is that it’s capable of working through media that other networks would balk at. Whether it’s controlling home automation through metal heating ducts or providing an alternative to LoRa at 433 MHz, it’s definitely worth a second look. We’ve mentioned it before, but remain surprised that we haven’t seen it more often since. Take a look, the video is below the break.

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That’s It, No More European IPV4 Addresses

November 29, 2019 by 80 Comments

When did you first hear concern expressed about the prospect of explosive growth of the internet resulting in exhaustion of the stock of available IP addresses? About twenty years ago perhaps? All computers directly connected to the internet must have an individual unique address, and the IPv4 scheme used since the 1980s has a 32-bit address space that provides only 4,294,967,296 possibilities. All that growth now means that IPv4 addresses are now in short supply, and this week RIPE, the body which allocates them in Europe, has announced that it no longer has any to allocate. Instead of handing new address blocks they will instead now provide ones that have been relinquished for example by companies that have gone out of business, and parties interested can join a waiting list.

Is the Internet dead then? Hardly, because of course IPv6, the replacement for IPv4, has been with us for decades and has a much larger 128-bit address space. The problem is that there is a huge installed base of IPv4 infrastructure which has always been cited as the reason to delay its adoption, so the vast majority of the internet-connected world has remained with IPv4. Even in an IPv4 world there are opportunities to be more efficient in the use of addresses such as the network address translation or NAT that many private networks use to share one address between many hosts, so it’s not quite curtains for your smart TV or IoT light bulb even though the situation will not get any easier.

The mystery comes in why after so many years we still use IPv4 so much. Your home router and millions like it will pick up an IPv4 address from your broadband provider’s pool, and there seems little reason why it can not instead pick up an IPv6 address and contain a gateway between the two. The same goes for addresses outside the domestic arena, and even in out community we find that IPv6 networks at events are labelled as experimental. Perhaps this news will spur the change, but meanwhile we don’t expect to be using an IPv6 address day-to-day very soon.

We know among Hackaday’s readership there will be people close to the coalface when it comes to IPv6 adoption. As always the comments are open, and we’d like to hear your views.

Header: Robert.Harker [CC BY-SA 3.0].

Ethernet, Over DC Power

November 14, 2019 by 63 Comments

We’re used to extending our network connections and being no longer constrained in our use of Ethernet by proximity to a switch or hub. Our houses routinely contain wireless networks, and of course powerline-Ethernet units passing data over our mains wiring. [Peter Franck] had a similar problem but without the mains power, for a distributed sprinkler system he needed to send Ethernet over DC cables.

The solution is a surprisingly simple one, taking one of those powerline Ethernet units and converting it by removing its mains power section. These devices contain the Ethernet and powerline modem chip with its associated circuitry, and a small switch-mode power supply. He’s removed the power supply and put in a capacitive coupling to the DC cabling, resulting in a relatively inexpensive DC powerline network device.

Powerline Ethernet devices are not without their own issues, for instance they are not popular with radio amateurs due to their effect on the RF noise floor. We’d therefore be curious to see what the RF emissions are like for this hack, but we still think it’s a useful weapon in the armoury as well as something to do with all those surplus powerline Ethernet bricks.