Receiver board of the Ethernet tester, with only probing pins, and no resistors populated

Ethernet Tester Needs No LEDs, Only Your Multimeter

February 28, 2022 by Arya Voronova 27 Comments

Ethernet cable testers are dime a dozen, but none of them are as elegant and multimeter-friendly as this tester from our Hackaday.io regular, [Bharbour]. An Ethernet cable has 8 wires, and the 9 volts of easily available batteries come awfully close to that – which is why the board has a voltage divider! On the ‘sender’ end, you just plug this board onto the connector, powered by a 9 volt battery. On the “receiver” end, you take your multimeter out and measure the testpoints – TP7 should be at seven volts, TP3 at three volts, and so on.

As a result, you can easily check any of the individual wires, as opposed to many testers which only test pair-by-pair. This also helps you detect crossover and miswired cables – while firmly keeping you in the realm of real-life pin numbers! This tester is well thought-out when it comes to being easily reproducible – the PCB files are available in the “Files” section, and since the “receiver” and “sender” PCBs are identical, you only need to do a single “three PCBs” order from OSHPark in order to build your own!

Bharbour has a rich library of projects, and we encourage you to check them out! If you ever want to get yourself up to speed on Ethernet basics, we’ve talked about its entire history – and we’ve even explained PoE! After some intensive learning time, perhaps you can try your hand at crimping the shortest Ethernet cable ever.

Remote control PCB next to its shell, with a breadboarded analog switch connected to the remote's onboard microcontroller, soldered to the pins responsible for button reading

Reusing Proprietary Wireless Sockets Without Wireless Hacking

January 31, 2022 by Arya Voronova 9 Comments

Bending various proprietary devices to our will is a hacker’s rite of passage. When it comes to proprietary wall sockets, we’d often reverse-engineer and emulate their protocol – but you can absolutely take a shortcut and, like [oaox], spoof the button presses on the original remote! Buttons on such remotes tend to be multiplexed and read as a key matrix (provided there’s more than four of them), so you can’t just pull one of the pads to ground and expect to not confuse the microcontroller inside the remote. While reading a key matrix, the controller will typically drive rows one-by-one and read column states, and a row or column driven externally will result in the code perceiving an entire group of keys as “pressed” – however, a digitally-driven “switch” doesn’t have this issue!

One way to achieve this would be to use a transistor, but [oaox] played it safe and went for a 4066 analog multiplexer, which has a higher chance of working with any remote no matter the button configuration, for instance, even when the buttons are wired as part of a resistor network. As a bonus, the remote will still work, and you will still be able to use its buttons for the original purpose – as long as you keep your wiring job neat! When compared to reverse-engineering the protocol and using a wireless transmitter, this also has the benefit of being able to consistently work with even non-realtime devices like Raspberry Pi, and other devices that run an OS and aren’t able to guarantee consistent operation when driving a cheap GPIO-operated RF transmitter.

In the past, we’ve seen people trying to tackle this exact issue, resorting to RF protocol hacking in the end. We’ve talked about analog multiplexers and switches in the past, if you’d like figure out more ways to apply them to solve your hacking problems! Taking projects like these as your starting point, it’s not too far until you’re able to replace the drift-y joysticks on your Nintendo Switch with touchpads!

IPod Mod Puts Pi Zero In New Bod

November 20, 2021 by Michael Shaub 7 Comments

We sure love to see nicely designed products get a new lease on life. Just as the new Raspberry Pi Zero 2 was being announced, [production] was stuffing an original RPi Zero into an old iPod’s case.

[production] cites several previous, similar projects that showed how to interface with the click-wheel, a perfectly fitting color display from Waveshare, and open-source software called Rockbox to run on the pi. We all stand on the shoulders of giants.

Some nice innovations to look for are the Pi Zero’s micro-SD card and a micro-USB charging port aligned to the large slot left from the iPod’s original 40 pin connector. Having access for charging and reflashing the card without opening the case seems quite handy. There’s a nice sized battery too, though we wonder if a smaller battery and a Qi charger could fit in the same space. Check the project’s Hackaday.io for the parts list, and GitHub for the software side of things, and all the reference links you’ll need to build your own. It looks like [production] has plans to turn old iPods into Gameboy clones, you may want to check back for progress on that.

If you just want to rock like it’s 2004, there are options to just upgrade the battery and capacity but keep your vintage iPod too.

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A Raspberry Pi next to a small circuit board

An Inexpensive FM Receiver For The Raspberry Pi

September 7, 2021 by Chris Wilkinson 38 Comments

At this point, there are no shortage of impressive hacks for the Raspberry Pi. [Dilshan Jayakody] recently documented his experience in designing and building an inexpensive FM Stereo Receiver for the Pi platform, and the results are impressive.

Quite a few FM receiver projects center around the RDA5807 or TEA5767 ICs, however [Dilshan] has used the QN8035 by Quintic Corporation in his build. A handful of discrete components on a pleasing single-sided PCB is all that is needed to interface the QN8035 with the Pi’s I2C bus.

After demonstrating that the FM tuner could be, well, tuned at the command line, [Dilshan] then coded a smart looking GUI application that makes tuning a breeze. The software allows the listener to manually and automatically scan through FM stations, decode program service data, control the volume, and display the RSSI and SNR readings from the tuner.

As we reported earlier, FM radio is on a slow decline into obsolescence. This latest project isn’t aiming to break new ground, however its simplicity and inexpensive components are the perfect combination for beginner hackers and radio enthusiasts alike. More details can be found over on Hackaday.io. The schematic, source code and bill of materials can be found on GitHub.

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A rectangle-shaped wristband wearable, worn on a wrist

A Digital White Cane For The Visually Impaired

August 12, 2021 by Chris Wilkinson 22 Comments

The white cane (and its many variants) is an everyday carry for many visually impaired people. This low-tech tool allows those afflicted by visual impairment to safely navigate the world around them, and has been ubiquitous in many parts of the world for decades. [Madaeon] has been hard at work going one step further in prototyping an open-source assistive wearable that could help in situations where a cane is not practical, or useful.

The T.O.F Wristband V2 alerts its wearer to nearby obstacles through vibrations, and is able to detect objects up to four meters away. As the wearer veers closer and closer to an obstacle, the vibration increases in frequency. A time-of-flight distance sensor is controlled by a Feather, and the whole system is powered by a small lithium-polymer battery. The prototype consists of just four components plus a 3D printed case and bracelet, which inevitably keeps down costs and complexity.

Version two of this project picks up where version one left off. In that project, [Madaeon] mentioned the possibility of squeezing this project down to the size of a ring. Perhaps with better battery technology, a ring-sized sensor might just be possible one day.

This isn’t the first wearable that has set out to assist the visually impaired. Back in 2019 we covered a laser-augmented glove that attempts something very similar.

By some estimates, nearly one billion people worldwide have some degree of visual impairment. Assistive devices like the T.O.F Wristband V2, and others like it, offer these people the potential for greater independence and an improved standard of living.

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Hackaday Links: December 27, 2020

December 27, 2020 by Dan Maloney 26 Comments

We’re always pleased to see one of our community’s projects succeed, and we celebrate that success in whatever what it comes. But seeing a company launched to commercialize an idea that started as a Hackaday.io project and a Hackaday Prize entry is especially gratifying. So we were pleased as punch to see that MAKESafe Tools has managed to bring the idea of add-on machine tool braking to market. We’d love to add this to several tools in our shop. Honestly, of all the terrifying ways machine tools can slice, dice, and shred human flesh asunder, we always considered the lowly bench grinder fairly low-risk — and then we had a chance to “Shake Hands with Danger.”

Another great thing about the Hackaday community is the way we all try to keep each other up to speed on changes and news that affects even our smallest niches. Just last week Tom Nardi covered a project using the venerable TI eZ430-Chronos smartwatch as a makeshift medical alert bracelet for a family member. It’s a great application for the proto-smartwatch, but one eagle-eyed commenter helpfully pointed out that TI is shutting down their processors wiki in just a couple of weeks. The banner at the top of each page warns that the wiki is not read-only and that any files needed should be downloaded by January 15. Also helpfully, subsequent comments include instructions to download the entire wiki and a torrent link to the archive. It’s always sad to see a platform lose support, especially one that has gained a nice following, but it’s heartening to see the community pull together to continue to support each other like this.

We came across an interesting article this week that’s was a fascinating glimpse into how economic forces shape and drive technological process, and vice versa. It turns out that some of the hottest real estate commodities these days are the plots of land occupied by AM radio stations serving metropolitan markets. It’s no secret that terrestrial radio in general, and AM radio in particular, are growing increasingly moribund, and the infrastructure needed to keep them on the air is getting harder and harder to justify. Chief among these are the large tracts of land devoted to antenna farms, which are often located in suburban and exurban areas near major cities. They’re tempting targets for developers looking to plunk down the physical infrastructure needed to support “New Economy” players like Amazon, which continue to build vast automated warehouses in areas that are handy to large customer bases. It’s a bit sad to watch a once mighty industry unravel and be sold off like this, but such is the nature of progress.

And finally, you may recall a Links article mention a few weeks back about a teardown of a super-sized IBM processor module. A quarter-million dollar relic of the 1990s, the huge System/390 module was an engineering masterpiece that met an unfortunate end at the hands of EEVblog’s Dave Jones. As a follow-up, Dave teamed up with fellow YouTuber CPU Galaxy to take a less-destructive tour of the module using X-ray analysis. The level of engineering needed for a 64-layer ceramic backplane is astonishing, and Dave’s play-by-play is pretty entertaining too. As a bonus, CPU Galaxy has some really interesting stuff; his place is basically a museum of vintage tech, and he just earned a new sub.

Brain Hacking With Entrainment

April 8, 2019 by Al Williams 16 Comments

Can you electronically enhance your brain? I’m not talking about surgically turning into a Borg. But are there electronic methods that can improve various functions of your brain? Fans of brainwave entrainment say yes.

There was an old recruiting ad for electrical engineers that started with the headline: The best electronic brains are still human. While it is true that even a toddler can do things our best computers struggle with, it is easy to feel a little inadequate compared to some of our modern electronic brains. Then again, your brain is an electronic device of sorts. While we don’t understand everything about how it works, there are definitely electric signals going between neurons. And where there are electric signals there are ways to measure them.

The tool for measuring electric signals in the brain is an EEG (electroencephalograph). While you can’t use an EEG to read your mind, exactly, it can tell you some pretty interesting information, such as when you are relaxed or concentrating. At its most basic we’ve seen toys and simple hobby projects that purport to be “mind controlled” but only at an incredibly rudimentary level.

Brainwave entrainment is a hypothesis that sending low frequency waves to your brain can give your mind a nudge and sync up brain activity with the equipment measuring it. The ability to synchronize with the brain could yield much better measurements for a meaningful interface between modern electronics and electric storm of thought happening in your head.

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