Creating A Numbers Station Of Your Very Own

March 17, 2024 by 13 Comments

Numbers stations are a weird phenomenon where odd voices read out long strings of numbers or random codewords to the confusion of the vast majority of the listening audience. If you’ve ever wanted to build one of your own, you could follow the example of [AudioWanderer].

NumberMumble, as it’s called, is a numbers station emulator. It doesn’t signal spy networks or reveal national secrets. Instead, it randomly plays audio samples using an Arduino, including characteristic bursts of white noise that make it sound more authentic. It relies on the Mozzi library to help with audio tasks, including generating white noise and playing back samples. It’s also kitted out with a filter knob for varying the tone. Audio output is via PWM.

If you want to confuse your neighbours with oddball audio, put this thing on a radio transmitter and get broadcasting. But don’t, because that’s illegal without the proper licenses or — you know — if you happen to be a real spy. Video after the break.

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The Most Famous Room In Rock-n-Roll You’ve Never Seen

March 17, 2024 by 6 Comments

The study of audio technology has a lot of fascinating branches, and one or two of them even take the curious engineer not into electronics but into architecture. There’s the anechoic chamber with its complete lack of echo, but at the other end of the scale, there’s the echo chamber.

It’s normal in 2024 when searching for reverb to reach for a software plugin, but following the effect back through silicon, spring lines, and metal plates to the 1950s, we find an echo chamber as a real room with a speaker and a microphone placed in it. [Rick Beato] takes us into the echo chamber, starting with one of the few remaining originals and probably the one whose effect has been heard on the most highly-charting music, at the famous Abbey Road studio in London.

The video below the break is broadly in two parts, with the first concentrating on the Abbey Road chamber and the second showing how an empty room in a house can be used to make your own. It’s aimed at musicians rather than hardware hackers but we think it’s one of those moments of crossover that readers might find interesting. We were particularly curious about the tall ceramic tubes in the Abbey Road chamber, designed to further break up the sound waves for a greater depth of reverb.

The video shows how reverb can be achieved with just a room, but don’t worry if you’re space limited. A plate reverb needn’t break the bank. Or, grab a spring.

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Arduino Turned Into Something Kinda Like A Pager

March 16, 2024 by 13 Comments

Video may have killed the radio star, but cell phones and smart phones all but killed the pager. They still exist, of course, but only in very niche applications. [João Santos] wanted a pager-like experience for himself, though, so he enlisted an Arduino and got to work. Watch a video of the system working below.

The build uses an Arduino Uno to drive a simple HD44780 LCD display with 16 characters each across two lines of text. It’s hooked up to a Wemos D1, which uses its WiFi connection to get online. To this end, it’s capable of talking to a web application which allows users to enter text messages. It receives these messages, passes them to the Arduino Uno over I2C, and then the Uno shuttles the message to the display. It’s overkill, but [João] just found it quicker to get everything up and running via this route.

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diagram of the radicle node-to-node connectivity

Radicle: An Open-Source, Peer-to-Peer, GitHub Alternative

March 16, 2024 by 26 Comments

The actions of certain large social networks have recently highlighted how a small number of people possess significant power over the masses and how this power is sometimes misused. Consequently, there has been a surge in the development of federated (or decentralized) services, such as Mastodon and Matrix.  But what about development? While GitHub and similar services are less likely to be used for political manipulation, they are still centralized services with a common failure point. Radicle is an open-source, peer-to-peer collaboration stack built on top of Git but backed with public key cryptography as a standard and a gossip protocol to ensure widespread data sharing across the network and, thus, some fault tolerance.

Essentially, code and associated documentation are secured cryptographically with an identity. The Git protocol is used for actual data transfer from peer-to-peer, which means that updates are only sent as deltas, not complete copies, maximizing channel bandwidth efficiency. A custom gossip protocol is used for metadata transfer around the network of peers. The projects had a local-first ideology, with users running a full-stack node on their hardware and all features available, even offline, which is great for laptop users who move around locations with sporadic access to the internet.

Judging from their Zulipchat instance, this is a highly active space, so perhaps it is worth diving in and seeing if it floats your boat. Fancy getting onto the Fediverse, but only have a spare MS-DOS machine to try it on? We’ve got it covered. Want to use Git but not online? You need a private Git server. Finally, too much Git? How about Gitless?

Thanks [Anonymous] for the tip! No, that wasn’t lost on us :D

NASA Engineers Poke Voyager 1 And Receive Memory Dump

March 16, 2024 by 59 Comments

For months, there has been a rising fear that we may have to say farewell to the Voyager 1 spacecraft after it began to send back garbled data. Now, in a sudden twist, Voyager 1 sent back a read-out of the Flight Data Subsystem (FDS) memory after a “poke” command, which both gives some hope that the spacecraft is in a better condition than feared while also allows engineers to dig through the returned memory read-out for clues. Although this data was not sent in the format that the FDS is supposed to use when it’s working correctly, it’s nevertheless readable.

It was previously suspected that the issue lay with the telemetry modulation unit (TMU), but has since been nailed down to the FDS itself.  This comes after NASA engineers have been updating the firmware on both spacecraft to extend their lifespan, but it’s too early to consider this as a possible reason. Now, as a result of the “poke” instruction – which commands the computer to try different sequences in its firmware in case part of it has been corrupted – engineers can compare it to previous downloads to hopefully figure out the cause behind the FDS problems and a possible solution.

Inspired by this news of the decoded memory download, Nadia Drake – daughter of Frank Drake – wrote about how it affects not only the engineers who have worked on the Voyager mission for the past decades but also her own thoughts about the two Voyager spacecraft. Not only do they form a lasting reminder of her father and so many of his colleagues, but the silence that would follow if we can no longer communicate with these spacecraft would be profound. Still, this new hope is better than the earlier news about this plucky little spaceship.

Thanks to [Mark Stevens] for the tip.

A Simple Seismometer You Can Build Yourself

March 16, 2024 by 9 Comments

If you’re a child, there are certain things you’re taught even though they’re probably not directly relevant to your life. We teach young kids all about dinosaurs, and we teach older kids all about how the mitochondria is the powerhouse of the cell. We also teach kids about natural phenomena like earthquakes, and the equipment used to measure them. Namely, seismometers. You might like to satisfy your own child-like curiosity by building one of your own, like [mircemk] did.

Output from the build showing tremors in the Earth.

The build starts with a sensitive geophone of [mircemk’s] own design. That’s basically a microphone but it’s for picking up vibrations in the ground, not in the air. However, a geophone is not enough. You need to be able to pick up the signals from the geophone and then plot them if you want a seismometer.

First, the signals from the geophone must be amplified, which is achieved with a small circuit based around the LM358 op-amp. From there, the signal is sent to an Arduino where the output is captured via the analog-to-digital converter. This passes the signal to an attached PC which plots the results using a piece of software called NERdaq, which was developed for schools that built their own slinky-based seismometers.

[mircemk] reports that this setup has served as a reliable tool for visualizing earthquake activity for over 6 years. Though, it bears noting, it’s not calibrated so don’t expect to get science grade results out of it. Regardless, though, it’s a super cool way to understand more about what is going on with the geology around us. Video after the break.

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