Older hackers will remember that a crystal set radio receiver was often one of the first projects attempted. Times have changed, but there’s still something magical about gathering invisible signals from the air and listening to the radio on a homemade receiver. [mircemk] has brought the idea right up to date by building an FM radio with an OLED display, controlled with a rotary encoder.
The design is fairly straightforward, based as it is on another project that [mircemk] found on another site, but the build looks very slick and would take pride of place on any hacker’s workbench. An Arduino Due forms the heart of the project, controlling a TEA5767 module, an SH1106 128×64 pixel OLED display and a rotary encoder. The sound signal is passed through an LM4811 headphone amplifier for private listening, and a PAM8403 Class D audio amplifier for the built-in loudspeaker. The enclosure is made from PVC panels, and accented with colored adhesive tape for style.
It’s easier than ever before to quickly put together projects like this by connecting pre-built modules and downloading code from the Internet, but that doesn’t mean it’s not a worthwhile way to improve your skills and make some useful devices like this one. There are so many resources available to us these days and standing on the shoulders of giants has always been a great way to see farther.
Before the days of MP3 players and smartphones, and even before portable CD players, those of us of a certain age remember that our cassette players were about the only way to take music on-the-go. If we were lucky, they also had a built-in radio for when the single tape exhausted both of its sides. Compared to then, it’s much easier to build a portable radio even though cassettes are largely forgotten, as [wagiminator] shows us with this radio design based on an ATtiny.
The build is about as compact as possible, with the aforementioned ATtiny 402/412 as its core, it also makes use of an integrated circuit FM tuner, an integrated audio amplifier with its own single speaker, and a small OLED display. The unit also boasts its own lithium-polymer battery charger and its user interface consists of only three buttons, plenty for browsing radio stations and controlling volume.
The entire build fits easily in the palm of a hand and is quite capable for a mobile radio, plus all of the schematics and code is available on the project page. While it doesn’t include AM capability, just the fact that FM is this accessible nowadays when a few decades ago it was cutting-edge technology is quite remarkable. If you’re looking for an even smaller FM receiver without some of the bells and whistles of this one, take a look at this project too.
With music consumption having long ago moved to a streaming model in many parts of the world, it sometimes feels as though, just like the rotary telephone dial, kids might not even know what a radio was, let alone own one. But there was a time when broadcasting pop music over the airwaves was a deeply subversive activity for Europeans at least, as the lumbering state monopoly broadcasters were challenged by illegal pirate stations carrying the cutting edge music they had failed to provide. [Ringway Manchester] has the story of one such pirate station which broadcast across the city for a few years in the 1970s, and it’s a fascinating tale indeed.
It takes the form of a series of six videos, the first of which we’ve embedded below the break. The next installment is placed as an embedded link at the end of each video, and it’s worth sitting down for the full set.
We have to admit, it was hard not to be insufferably smug this week when Facebook temporarily went dark around the globe. Sick of being stalked by crazy aunts and cousins, I opted out of that little slice of cyber-hell at least a decade ago, so Monday’s outage was no skin off my teeth. But it was nice to see that the world didn’t stop turning. More interesting are the technical postmortems on the outage, particularly this great analysis by the good folks at the University of Nottingham. Dr. Steve Bagley does a great job explaining how Facebook likely pushed a configuration change to the Border Gateway Protocol (BGP) that propagated through the Internet and eventually erased all routes to Facebook’s servers from the DNS system. He also uses a graphical map of routes to show peer-to-peer connections to Facebook dropping one at a time, until their machines were totally isolated. He also offers speculation on why Facebook engineers were denied internal access, sometimes physically, to their own systems.
It may be a couple of decades overdue, but the US Federal Communications Commission finally decided to allow FM voice transmissions on Citizen’s Band radios. It seems odd to be messing around with a radio service whose heyday was in the 1970s, but Cobra, the CB radio manufacturer, petitioned for a rule change to allow frequency modulation in addition to the standard amplitude modulation that’s currently mandatory. It’s hard to say how this will improve the CB user experience, which last time we checked is a horrifying mix of shouting, screaming voices often with a weird echo effect, all put through powerful — and illegal — linear amps that distort the signal beyond intelligibility. We can’t see how a little less static is going to improve that.
Can you steal a car with a Game Boy? Probably not, but car thieves in the UK are using some sort of device hidden in a Game Boy case to boost expensive cars. A group of three men in Yorkshire used the device, which supposedly cost £20,000 ($27,000), to wirelessly defeat the security systems on cars in seconds. They stole cars for garages and driveways to the tune of £180,000 — not a bad return on their investment. It’s not clear how the device works, but we’d love to find out — for science, of course.
There have been tons of stories lately about all the things AI is good for, and all the magical promises it will deliver on given enough time. And it may well, but we’re still early enough in the AI hype curve to take everything we see with a grain of salt. However, one area that bears watching is the ability of AI to help fill in the gaps left when an artist is struck down before completing their work. And perhaps no artist left so much on the table as Ludwig von Beethoven, with his famous unfinished 10th Symphony. When the German composer died, he had left only a few notes on what he wanted to do with the four-movement symphony. But those notes, along with a rich body of other works and deep knowledge of the composer’s creative process, have allowed a team of musicologists and AI experts to complete the 10th Symphony. The article contains a lot of technical detail, both on the musical and the informatics sides. How will it sound? Here’s a preview:
And finally, Captain Kirk is finally getting to space. William Shatner, who played captain — and later admiral — James Tiberius Kirk from the 1960s to the 1990s, will head to space aboard Blue Origin’s New Shepard rocket on Tuesday. At 90 years old, Shatner will edge out Wally Funk, who recently set the record after her Blue Origin flight at the age of 82. It’s interesting that Shatner agreed to go, since he is said to have previously refused the offer of a ride upstairs with Virgin Galactic. Whatever the reason for the change of heart, here’s hoping the flight goes well.
Had the pandemic not upended many of this summer’s fun and games, many of my friends would have made a trip to the MCH hacker camp in the Netherlands earlier this month. I had an idea for a game for the event, a friend and I were going to secrete a set of those low-power FM transmitters as numbers stations around the camp for players to find and solve the numerical puzzles they would transmit. I even bought a few cheap FM transmitter modules from China for evaluation, and had some fun sending a chiptune Rick Astley across a housing estate in Northamptonshire.
To me as someone who grew up with FM radio and whose teen years played out to the sounds of BBC Radio 1 FM it made absolute sense to do a puzzle in this way, but it was my personal reminder of advancing years to find that some of my friends differed on the matter. Sure, they thought it was a great idea, but they gently reminded me that the kids don’t listen to any sort of conventional broadcast radio these days, instead they stream their music, so very few of them would have the means for listening to my numbers stations. Even for me it’s something I only use for BBC Radio 4 in the car, and to traverse the remainder of the FM dial is to hear a selection of easy listening, oldies, and classical music. It’s becoming an older person’s medium, and it’s inevitable that like AM before it, it will eventually wane.
There are two angles to this that might detain the casual hacker; first what it will mean from a broadcasting and radio spectrum perspective, and then how it is already influencing some of our projects.
Building radio receivers from scratch is still a popular project since it can be done largely with off-the-shelf discrete components and a wire long enough for the bands that the radio will receive. That’s good enough for AM radio, anyway, but you’ll need to try this DIY FM receiver if you want to listen to something more culturally relevant.
Receiving frequency-modulated radio waves is typically more difficult than their amplitude-modulated cousins because the circuitry necessary to demodulate an FM signal needs a frequency-to-voltage conversion that isn’t necessary with AM. For this build, [hesam.moshiri] uses a TEA5767 FM chip because of its ability to communicate over I2C. He also integrated a 3W amplifier into this build, and everything is controlled by an Arduino including a small LCD screen which displays the current tuned frequency. With the addition of a small 5V power supply, it’s a tidy and compact build as well.
While the FM receiver in this project wasn’t built from scratch like some AM receivers we’ve seen, it’s still an interesting build because of the small size, I2C capability, and also because all of the circuit schematics are available for all of the components in the build. For those reasons, it could be a great gateway project into more complex FM builds.
It started with an old TV sound chip, and some curiosity. The TDA1701 that [Philip Bragg] found in a box of junk is a complete FM IF strip and audio power amplifier from the golden age of analogue PAL televisions, and while it was designed for the 5.5 MHz or 6 MHz FM subcarrier of European broadcast TV, he found it worked rather well at the more usual 10.7 MHz of a radio receiver. There followed a long thread detailing the genesis bit-by-bit of a decent quality VHF radio receiver, built dead-bug-style on a piece of PCB material.
The TDA1701 was soon joined by a couple of stages of IF amplification with a ceramic filter, and then by several iterations of a JFET mixer. A varicap tuned MOSFET RF amplifier followed, and then a local oscillator. Finally it became a fully-functional FM radio, with probably far better performance than most commercial radios. He admits tuning is a little impractical though, with what appears to be a cermet preset potentiometer covering the entire band.
We suspect this project isn’t finished, and we hope he posts the schematic. But it doesn’t really matter if he doesn’t, because the value here isn’t in the design. Instead it lies in the joy of creating an ad-hoc radio just for the fun of it, and that’s something we completely understand.
