ESP8266 Unlocks Hidden Features In Sound Bar

October 24, 2019 by Tom Nardi 22 Comments

It’s no secret that the hardware devices we buy are often more capable than their manufacturer leads on. Features hidden behind firmware locks are a common trick, as it allows companies to sell the same piece of gear as a different model by turning off certain capabilities. Luckily for us, these types of arbitrary limitations are often easy to circumvent.

As a perfect example, [Acuario] recently discovered that the LG SJ2 sound bar has quite a few features that aren’t advertised on the box. Whether it’s due to greed or just laziness, it turns out LG isn’t using many of the capabilities offered by the ESMT AD83586B IC inside the amplifier. The chip gets its configuration via I2C, so thanks to the addition of an ESP8266, the expanded capabilities can now be easily enabled through a web interface.

[Acuario] has already found out how to turn on things like simulated surround sound, or per-channel volume controls; all functions which aren’t even exposed through the normal controls on the sound bar. But it goes deeper than that. The LG SJ2 is a 2.1 channel system, with a wireless speaker providing the right and left channels. But the AD83586B inside the subwoofer is actually capable of driving two locally connected speakers, though you obviously need to do a little rewiring.

There are still even more capabilities to unlock, though [Acuario] is currently struggling with some incomplete documentation. The datasheet says there’s support for user-defined equalizer settings, but no examples are given for how to actually do it. If anyone’s got a particular affinity for these sort of amplifier chips, now could be your time to shine.

For hackers, there’s perhaps no better example of feature-locked products than Rigol’s line of oscilloscopes. From the 2000 series of scopes in 2013 up to their higher-end MSO5000 just last year, there’s a long history of unlocking hidden features on these popular tools.

Turn A Cheap Bluetooth Speaker Into An Audio Receiver

July 23, 2018 by Sven Gregori 16 Comments

Cheap Bluetooth speakers come in all different kinds of shapes and colors, and they let you conveniently stream music, for example from your mobile phone. For [mcmchris], they had one significant shortcoming though: while most of them come with some auxiliary input port as alternative audio source, they usually lack an audio output port that would let him route the audio to his more enjoyable big-speaker sound setup. Lucky for him, it’s a problem that can be fixed with a wire cutter and soldering iron, and so he simply turned his cheap speaker into a Bluetooth audio receiver.

After opening the speaker, [mcmchris] discovered a regular F-6188 Bluetooth audio module built around the BK8000L chip, with the audio jack connected to the chip’s aux input pins. Taking a close look at the PCB, the solution seemed obvious: cut the connection to the chip’s aux input pins, and connect the audio jack parallel to the audio signal itself. After some trial and error, the output pins of the on-board op amplifier seemed to provide the best audio signal for his shiny new output jack. You can see more details about the speaker’s inner life and a demonstration in the video after the break — in Spanish.

If the concept looks familiar to you, we’ve indeed seen a very similar approach to equip a Google Home Mini with an audio output jack before. The alternative is of course to just build a decent sized Bluetooth speaker yourself.

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Chewbacca Mask Hack Cheers Up The Whining Wookie

August 15, 2016 by Moritz Walter 4 Comments

Once tried, even grown-ups just can’t let go of that hilariously funny Chewbacca mask. Also, the speaking toy literally cries out to be hacked. Weary of the whining Wookie, [John Park] set out to bring variety into Chewie’s mode of expression, expanding the mask’s memory and vocabulary to unprecedented levels.

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Color-Changing LED Makes Techno Music

April 23, 2016 by Moritz Walter 25 Comments

As much as we like addressable LEDs for their obedience, why do we always have to control everything? At least participants of the MusicMaker Hacklab, which was part of the Artefact Festival in February this year, have learned, that sometimes we should just sit down with our electronics and listen.

With the end of the Artefact Festival approaching, they still had this leftover color-changing LED from an otherwise scavenged toy reverb microphone. When powered by a 9 V battery, the LED would start a tiny light show, flashing, fading and mixing the very best out of its three primary colors. Acoustically, however, it spent most of its time in silent dignity.

As you may know, this kind of LED contains a tiny integrated circuit. This IC pulse-width-modulates the current through the light-emitting junctions in preprogrammed patterns, thus creating the colorful light effects.

To give the LED a voice, the participants added a 1 kΩ series resistor to the LED’s “anode”, which effectively translates variations in the current passing through the LED into measurable variations of voltage. This signal could then be fed into a small speaker or a mixing console. The LED expressed its gratitude for the life-changing modification by chanting its very own disco song.

This particular IC seems to operate at a switching frequency of about 1.1 kHz and the resulting square wave signal noticeably dominates the mix. However, not everything we hear there may be explained solely by the PWM. There are those rhythmic “thump” noises, shifts in pitch and amplitude of the sound and more to analyze and learn from. Not wanting to spoil your fun of making sense of the beeps and cracks (feel free to spoil as much as you want in the comments!), we just say enjoy the video and thanks to the people of the STUK Belgium for sharing their findings.