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.
Continue reading “How To Hack A Portable Bluetooth Speaker By Skipping The Bluetooth”
The Sansa Clip+ is a nice little MP3 player and recorder. But it doesn’t offer an input connector, instead relying on the built-in microphone. [Simon Frank] wanted to extend its functionality so he figured out how to add a standard audio jack for analog input.
This is not the first time this has been done, but [Simon] has found a different method of accomplishing the task at hand. The other external input hack we saw cannibalized the internal microphone, rerouting its connections as an external input. But the method seen here keeps that microphone intact. The device includes an FM radio chip which is attached to an ADC on one of the devices other integrated circuits. [Simon] just patched into those signals. Now all he has to do is set up the device to record from the radio and connect his source to the jack which he epoxied to the base of the enclosure.
[Randy] had a cheap megaphone, and like most models in this price range, it didn’t have an audio input jack on board. He wanted the ability to pipe both music and audio from an external mic through the megaphone, and in a brief tutorial, he shows how he modified his bullhorn to do just that.
Most megaphones carry their electronics near the built-in mic, just outside the battery compartment. Removing the screws from the cap in [Randy’s] model revealed a circuit board and a couple of wires connecting it to the on board mic. His megaphone happened to play some canned music from a secondary circuit board, and he spliced in an audio jack with a built in cutoff switch between that and the main PCB. He also added a resistor in between his jack and the microphone circuitry to attenuate the line level signal properly. Once he reassembled everything, and then tested his input using a portable audio player, slowly ramping up the volume to the desired level.
It’s not every day that you require the ability to blast music through a bullhorn, but [Randy’s] modification is a great addition when you do need it.
Scratch input allows us to use solid surfaces as an input devices by capturing the sounds they produce. Using a stethoscope and a high pass filter, they capture the unique sounds of specific gestures. Custom software then translates this to actions for applications. The video shows some really cool stuff, like turning an entire wall into an input device. It goes around corners and past doorways. They even talk about potential using your clothes to capture input.