The speaker PCB inside of the speaker, with a flash chip ZIF holder soldered to the SPI flash pads on the PCB

Bluetooth Speaker Domesticated Through Firmware Mod

This might sound like a familiar problem – you get a Bluetooth speaker, and it sounds nice, but it also emits all kinds of weird sounds every now and then. [Oleg Kutkov] got himself a Sven PS460 speaker with FM radio functionality, but didn’t like that the “power on” sound was persistently loud with no respect for the volume setting, and the low battery notification sounds were bothersome. So, he disassembled the speaker, located a flash chip next to the processor, and started hacking.

Using a TL866 and minipro software, he dumped the firmware, and started probing it with binwalk. The default set of options didn’t show anything interesting, but he decided to look for sound file signatures specifically, and successfully found a collection of MP3 files! Proper extraction of these was a bit tricky, but he figured out how to get them out, and loaded the entire assortment into Audacity.

From there, he decided to merely make the annoying sounds quieter – negating the “no respect for the volume setting” aspect somewhat. After he exported the sound pack out of Audacity, the file became noticeably smaller, so he zero-padded it, and finally inserted it back into the firmware. Testing revealed that it worked just as intended! As a bonus, he replaced the “battery low” indicator sound with something that most of us would appreciate. Check out the demo video at the end of his write-up.

Domesticating your Bluetooth speakers tends to be called for. If you can’t do that for whatever reason, you can rebuild them into an audio receiver – or perhaps, build your own Bluetooth speakers, with aesthetics included and annoyance omitted from the start.

Print Your Own Wireless 2.1 Speaker System

Buying a set of stylish bookshelf speakers is a perfectly reasonable thing to do, and remains legal in most free countries around the world. However, if you really want to impress with a pretty pair to crank out your tunes, you might consider designing and printing your own. [EH_Design] did just that with a stylish 2.1 Bluetooth audio system.

The 2.1 designation refers to the use of two stereo channels plus a subwoofer. It’s a popular setup as human perception means it’s not as necessary to have stereo imaging for low frequency content. The build uses a Texas Instruments TPA3116D2 Class D amplifier with a Bluetooth input, with the efficient design allowing the build to be more compact without the need for as much heat sinking. A 24 V supply delivering up to 3 A is specified, providing plenty of volume when needed. The speakers themselves consist of 3″ drivers mounted in attractive 3D-printed shells, with the “subwoofer” consisting of a pair of 5″ woofers paired up in a special isobaric enclosure that enables a smaller volume to acoustically act like one double the size.

The result is a futuristic-looking set of bookshelf speakers that remind us of some of the fancier high-end sets often seen in hi-fi magazines. Of course, if 3D printing enclosures isn’t enough for you, you could always consider 3D printing the actual speaker driver itself. When you do, let us know how it goes!

 

ESP32 Spectrum Analyzer Taps Into Both Cores

We probably don’t need to tell the average Hackaday reader that the ESP32 is a powerful and extremely flexible microcontroller. We’ve seen some incredible projects using this affordable chip over the last few years, and by the looks of it, the best is yet to come. That’s because it always takes some time before the community can really figure out how to get the most out of a piece of hardware.

Take for example the Bluetooth audio player that [squix] was recently working on. Getting the music going was no problem with the esp32-a2dp library, but when he wanted to add some visualizations the audio quality took a serious hit. Realizing that his Fast Fourier transform (FFT) code was eating up too much processor power, it seemed like a great time for him to explore using the ESP32’s second core.

[squix] had avoided poking around with the dual-core nature of the ESP32 in the past, believing that the second core was busy handling the WiFi communication. But by using the FreeRTOS queue system, he wrote some code that collects audio data with one core and runs the actual FFT magic on the other. By balancing the workload like this, he’s able to drive the array of 64 WS2812B LEDs on the front of the Icon64 seen in the video after the break.

Even if you’re not terribly interested in running your own microcontroller disco, this project may be just the example you’ve been waiting for to help get your mind wrapped around multitasking on the ESP32. If you want to master a device with this many tricks up its sleeve, you’ll need all the help you can get.

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How To Hack A Portable Bluetooth Speaker By Skipping The Bluetooth

Portable Bluetooth speakers have joined the club of ubiquitous personal electronics. What was once an expensive luxury is now widely accessible thanks to a prolific landscape of manufacturers mass producing speakers to fit every taste and budget. Some have even become branded promotional giveaway items. As a consequence, nowadays it’s not unusual to have a small collection of them, a fertile field for hacking.

But many surplus speakers are put on a shelf for “do something with it later” only to collect dust. Our main obstacle is a side effect of market diversity: with so many different speakers, a hack posted for one speaker wouldn’t apply to another. Some speakers are amenable to custom firmware, but only a small minority have attracted a software development community. It doesn’t help that most Bluetooth audio modules are opaque, their development toolchains difficult to obtain.

So what if we just take advantage of the best parts of these speakers: great audio fidelity, portability, and the polished look of a consumer good, to serves as the host for our own audio-based hacks. Let’s throw the Bluetooth overboard but embrace all those other things. Now hacking these boxes just requires a change of mindset and a little detective work. I’ll show you how to drop an Arduino into a cheap speaker as the blueprint for your own audio adventures.

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Pelican Case Becomes Thumping Bluetooth Speaker

Pelican cases are great if you need a rugged enclosure to protect some sensitive gear. They’re also highly moddable, and can make a great base for a Bluetooth speaker build.

Like many modern builds, this is very much a case of wiring together a series of off-the-shelf modules into a larger whole. A Tinyshine Bluetooth audio board is hooked up to a Dayton Audio Class D amplifier. Class D amplifiers are a great choice for any portable audio application for their compact size and good power efficiency. Power is supplied by a hand-built 3-cell 18650 pack, while a standard buck converter and battery protection board are subbed in to make sure the batteries stay happy.

Not wanting to skimp on audio quality, a pair of Dayton Audio full-range drivers are installed, negating the need for a crossover install, or multiple drivers per channel. There’s a third passive driver on the back side as well, though we’re not 100% clear on its purpose. If you’re clued in, let us know in the comments.

It’s a project that serves as a great blueprint for anyone wanting to build their own high-fidelity Bluetooth speaker. The relevant modules are all readily available – it’s just a case of hooking them up to a nice amp and a decent set of speakers. The design is all up to you – whether you go for a pipe, a bag, or something altogether entirely. Happy hacking!

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PVC Pipe Turned Portable Bluetooth Speaker

We’ve always felt that sections of PVC pipe from the home improvement store are a criminally underutilized construction material, and it looks like [Troy Proffitt] feels the same way. Rather than trying to entirely 3D print the enclosure for his recently completed portable Bluetooth speaker, he combined printed parts with a piece of four inch pipe from the Home Depot.

While using PVC pipe naturally means your final hardware will have a distinctly cylindrical look, it does provide compelling advantages over trying to print the entire thing. For one, printing an enclosure this large would have taken hours or potentially even days. But by limiting the printed parts to accessories like the face plate, handle, and caps, [Troy] reduced that time considerably. Of course, even if you’re not in a rush, it’s worth mentioning that a PVC pipe will be far stronger than anything your desktop FDM printer is likely to squirt out.

[Troy] provides links for all the hardware he used, such as the speakers, tweeters, and the Bluetooth audio board itself. The system is powered by an 1800 mAh 3S RC-style battery pack that he says lasts for hours, though he also links to a wall adapter that can be used if you don’t mind being tethered. Unfortunately it doesn’t look like he has any internal shots of the build, but given the relatively short parts list, we imagine it’s all fairly straightforward inside.

While this is certainly a respectable looking build considering it started life in the plumbing aisle, we have to admit that we’ve seen some portable Bluetooth speakers with fully 3D printed enclosures in the past that looked absolutely phenomenal. The tradeoff seems pretty clear: reuse existing materials to save time, print them if you don’t mind reinventing the wheel occasionally.

“Vintage” Radio Gets A Modern Makeover

Taking an old piece of gear and cramming it full of modern hardware is a very popular project. In fact, it’s one of the most common things we see here at Hackaday, especially in the Raspberry Pi era. The appeal is obvious: somebody has already done the hard work of designing and building an attractive enclosure, all you need to do is shoehorn your own gear into it. That being said, we know some of our beloved readers get upset when a vintage piece of gear gets sacrificed in the name of progress.

Thankfully, you can put your pitchforks down for this one. The vintage radio [Freshanator] cannibalized to build this Bluetooth speaker is actually a replica made to invoke the classic “cathedral” look. Granted it may still have been older than most of the people reading this right now, but at least it wasn’t actually from the 1930’s.

To start the process, [Freshanator] created a 3D model of the inside of the radio so all the components could be laid out virtually before anything was cut or fabricated. This included the design for the speaker box, which was ultimately 3D printed and then coated with a spray-on “liquid rubber” to seal it up. The upfront effort and time to design like this might be high, but it’s an excellent way to help ensure you don’t run into some roadblock halfway through the build.

Driving the speakers is a TPA3116-based amplifier board with integrated Bluetooth receiver, which has all of its buttons broken out to the front for easy access. [Freshanator] even went the extra mile and designed some labels for the front panel buttons to be made on a vinyl cutter. Unfortunately the cutter lacked the precision to make them small enough to actually go on the buttons, so they ended up getting placed above or next to them as space allowed.

The build was wrapped up with a fan installed at the peak of the front speaker grille to keep things cool. Oh, and there are lights. Because there’s always lights. In this case, some blue LEDs and strategically placed EL wire give the whole build an otherworldly glow.

If you’re interested in a having a frustrating quasi-conversation with your vintage looking audio equipment, you could always cram an Echo Dot in there instead. Though if you go that route, you can just 3D print a classic styled enclosure without incurring the wrath of the purists.