Using The 74HC595 Shift Register To Drive 7-Segment Displays

August 21, 2025 by John Elliot V 19 Comments

In a recent video our hacker [Electronic Wizard] introduces the 74HC595 shift register and explains how to use it to drive 7-segment displays.

[Electronic Wizard] explains that understanding how to apply the 74HC595 can increase the quality of your projects and also help keep the demands on the number of pins from your microcontroller to manageable levels. If you’re interested in the gory details you can find a PDF datasheet for the 74HC595 such as this one from Texas Instruments.

[Electronic Wizard] explains further that a shift register is like a small one byte memory where its data is directly available on its eight output pins, no input address required. When you pulse the clock pin (CLK) each bit in the eight bit memory shifts right one bit, making room for a new bit on the left. The bits that fall off the right hand side can daisy chain into another 74HC595 going out on pin 9 and coming in on pin 14.

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From Smartphone To A Home Server

August 16, 2025 by Tyler August 27 Comments

Some people like their homelabs to be as big and fancy as possible, with racks of new or surplus server hardware sucking down power. [Hardware Haven] evidently has the opposite idea, given he just made a video about making the cheapest, smallest server possible: an Android phone.

Sure, it’s not going to be streaming terabytes of data at multiple gigabytes per second, but that’s not everyone’s use case. Don’t forget, flagship phones had multiple cores and gigabytes of RAM a decade ago, so even an old and busted smartphone has more than enough power for something like Home Assistant, which is what gets installed in this video.

After considering loading termux and rooting his device for Docker-on-Android, he opted for postmarket OS, the premiere Linux for old smartphones. That’s not because the Linux environment you get with termux wouldn’t work; it’s just that he wanted something native. To that end, he bought a somewhat worse-for-wear Xiaomi Mi A1 from eBay to get hardware Alpine-based postmarket could use.

Software wise, it was just a matter of following instructions and reading manuals — Linux is Linux, after all. The firewall proved to be his main challenge, though trying to branch out from Home Assistant to run Minecraft Server did run into Java issues [Hardware Haven] had no interest in troubleshooting. Hardware wise, though, well — do you want to leave a phone plugged in permanently? Smokey the Bear suggests you not, especially if you live near a forest. Besides, you probably don’t want your server on WiFi, and at least this smartphone wouldn’t charge when using a networking dongle.

That meant phone surgery: the battery came out, and 5 V from an old USB charger was piped into the battery charge controller via a diode. The diode was used for its voltage drop, to bring the 5 V supply down to a believable battery voltage — a buck converter might have been better, but you use what you have, and the diode drop doesn’t dissipate much power. Power dissipation is still one watt at idle, six during a stress test.

Given how cheap the phone was, and how little power this thing sips, [Hardware Heaven] has an excellent answer to those who say homelabbing is a rich person’s hobby. This project also reminds us that while our phones might not be as hackable as we’d like, they’re still far from totally locked down. You can even run NixOS on (some of) them.

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Everyone’s Invited To The Copyparty

July 30, 2025 by Tyler August 46 Comments

Setting up a file server can be intimidating to the uninitiated. There are many servers to choose from, and then you need to decide how to install it — Docker? Kubernates? Well, what’s all that then? [9001] has come to the rescue with Copyparty, a full-featured file server in a single Python script.

It’s light enough to run on nearly anything, and getting it running could not be easier: run copyparty-sfx.py, and you’ve got a server. There’s even a 32-bit .exe for older Windows machines — Windows 2000 seems to be the oldest version tested.

It’ll connect to anything, both in terms of the variety of protocols supported, and the browsers its web interface loads in. The GitHub documentation says browser support : “Yes”, which is pretty accurate going down the list. Sadly Copyparty’s pages do not work in NCSA Mosaic, but IE4 is A-OK.

There’s, FTP, TFTP, HTTP/HTTPS, WebDAV, SMB/CIFS, with unp/zeroconf/mdns/ssdp, etc etc. You need to check the readme for all features, some of which — like transcoding — are only available when dependencies such as ffmpeg installed on the server. Alternatively you can watch the video embedded below to get walked through the features. If the video whets your appetite, can also visit a read-only Copyparty server being demoed on a NUC sitting in [9001]’s basement.

Over the years we’ve seen plenty of folks create personal servers, but the focus is generally on the hardware side of things. While those with more software experience might prefer to configure the various services involved manually, we can definitely see the appeal of a project like Copyparty. In some ways it’s the inverse of the UNIX Philosophy: instead of doing one thing perfectly, this program is doing everything [9001] could think of, and doing it “good enough”.

Thanks to [pedropolis] for inviting us to the Copyparty via the tips line. Building a NAS? Writing software? Hardware?Whatever you do, the tips line is for you.

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A Cable Modem, The Way All Network Gear Should Be Mounted

July 27, 2025 by Jenny List 25 Comments

Home routers and cable modems are now extremely powerful devices, but they all suffer from the attention of their manufacturers’ design and marketing departments. Instead of neatly packaging them in functional cases, they impose aesthetics and corporate identity on them, usually resulting in a curvy plastic case that’s difficult to integrate with other network infrastructure. [The Eccentric Workshop] did something about this with their new Arris modem, by creating a new 19″ rack mount for it.

Unusually for such a device, the plastic case was easy to dismantle. There’s a PCB inside, and a light guide for its LEDs. A new lower-half case and light guide were designed and 3D printed, and the whole was then mounted in a 1U rack case. The special part of this hack perhaps lies in the front panel, a very professionally cut and laser etched affair complete with an Arris logo as though it were meant to be this way.

We also like having our infrastructure and other things in a rack here at Hackaday, and fondly remember the days when some surprisingly affordable boxes came with metal wings for rack mounting. It’s always possible to use a rack tray, but something like this is so much more attractive.

Listening To Ethernet Via Eurorack

July 26, 2025 by Lewin Day 9 Comments

Ethernet is how we often network computers together, particularly when they’re too important to leave on a fussy WiFi connection. Have you ever thought about listening to Ethernet signals, though? Well, you totally could, with the NSA selector from [wenzellabs].

The NSA selector is a Eurorack module, designed for use as part of a larger modular synthesizer. There are lots of fun jokes and references on the PCB, but the front panel really shows you what this module is all about. It’s got a pair of RJ45 jacks, ready to receive your Ethernet cables through which data is flowing. They’re paired with a single audio output jack. “Any bit on the network will be sent to the audio output,” [wenzellabs] explains.

The device operates in a relatively simple fashion. Network traffic from one jack is forwarded to the other, unmodified. However, it’s also spat out to a simple digital-to-analog converter and turned into audio. This thing doesn’t play digital audio formats or anything like that—it just turns raw Ethernet signalling into audible noise.

Raw signal noises might not sound very appealing, but let’s be real here. If you liked nice sounds, you wouldn’t be into Eurorack. Skip to 25:46 in the video below if you just want to hear the final product.

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Pulling At Threads With The Flipper Zero

July 15, 2025 by Adam Zeloof 13 Comments

Gone are the days when all smart devices were required an internet uplink. The WiFi-enabled IoT fad, while still upon us (no, my coffee scale doesn’t need to be on the network, dammit!) has begun to give way to low-power protocols actually designed for this kind of communication, such as ZigBee, and more recently, Thread. The downside of these new systems, however, is that they can be a bit more difficult in which to dabble. If you want to see just why your WiFi-enabled toaster uploads 100 MB of data per day to some server, you can capture some network traffic on your laptop without any specialized hardware. These low-power protocols can feel a bit more opaque, but that’s easily remedied with a dev board. For a couple of dollars, you can buy Thread radio that, with some additional hacking, acts as a portal between this previously-arcane protocol and your laptop — or, as [András Tevesz] has shown us, your Flipper Zero.

He’s published a wonderful three-part guide detailing how to mod one such $10 radio to communicate with the Flipper via its GPIO pins, set up a toolchain, build the firmware, and start experimenting. The guide even gets into the nitty-gritty of how data is handled transmitted and investigates potential attack vectors (less worrying for your Thread-enabled light bulb, very worrying for your smart door lock). This project is a fantastic way to prototype new sensors, build complicated systems using the Flipper as a bridge, or even just gain some insight into how the devices in your smart home operate.

In 2025, it’s easier than ever to get started with home automation — whether you cook up a solution yourself, or opt for a stable, off-the-shelf (but still hackable) solution like HomeAssistant (or even Minecraft?). Regardless of the path you choose, you’ll likely wind up with devices on the Thread network that you now have the tools to hack.

Picture of front and back of thumb drive enclosure

Jcorp Nomad: ESP32-S3 Offline Media Server In A Thumbdrive

July 13, 2025 by John Elliot V 27 Comments

[Jackson Studner] wrote in to let us know about his ESP32-based media server: Jcorp Nomad.

This project uses a ESP32-S3 to create a WiFi hotspot you can connect to from your devices. The hotspot is a captive portal which directs the user to a web-interface comprised of static HTML assets which are in situ with the various media on an attached SD card formatted with a FAT32 file system. The static HTML assets are generated by the media.py Python 3 script when the ESP32 boots.

This project exists because the typical Raspberry Pi media server costs more than an ESP32 does. The ESP32 is smaller too, and demands less power.

According to [Jackson] this ESP32-based solution can support at least four concurrent viewers. The captive portal is implemented with DNS and HTTP services from the ESP32. The firmware is an Arduino project that integrates a bunch of libraries to provide the necessary services. The Jcorp Nomad media template supports Books (in pdf files), Music (in mp3 files), and Movies and Shows (in mp4 files). Also there is a convention for including JPEG files which can represent media in the user-interface.

And the icing on the cake? The project files include STL files so you can 3D print an enclosure. All in all, a very nice hack.