ESP8266 Adds Web Control To Old Home Theater

March 6, 2020 by Tom Nardi 23 Comments

There was a time when you could hold onto a TV or A/V receiver for the better part of the decade and not feel as though you were missing out on the latest and greatest features. But today you’re lucky to get three years out of a “smart” TV before it’s either supplanted by a vastly improved version, or falls victim to some weird issue that (surprise, surprise) means you need to buy a new one.

A simple touch interface hosted on the ESP8266

Not content with the status quo of planned obsolescence, [aamarioneta] recently set out to add a sprinkling of modern convenience to a circa 2008 Denon AVR 2308 home theater receiver. Like any good A/V receiver, the AVR 2308 features a dizzying array of ports on the back panel, one of which happens to be for an external infrared receiver. This turned out to be the perfect place to jack in an ESP8266, earning this 12 year old receiver an honorary membership into the Internet of Things.

The interesting thing about this hack is that there’s actually no IR involved. Sure, the code could be used to drive an IR LED attached to the ESP8266’s GPIO pins, and the AVR 2308 would respond as if the original remote was being used; but where’s the fun in that? Thanks to the receiver port, they’re able to inject the IR codes directly into the device. It’s the same protocol, just without the photons.

With a simple web-interface running on the ESP8266, they can control the AVR 2308 from a smartphone’s browser anywhere in the house. From here it would only take a few more lines of code to tie it into an existing home automation system or add in support for Alexa voice control.

We love seeing projects that add modern features to older hardware, as that’s one less piece of gear sent to an early grave because its owner felt they were behind the curve. It’s getting a bit unfriendly out there for consumers, and anything that puts the power back into the owner’s hands is a step in the right direction.

Make A Set Of Headphones From Scratch

February 16, 2020 by Jenny List 7 Comments

There are a variety of ways to enjoy your audio, of which headphones are one. Making a set of headphones is a straightforward enough project, but [madaeon] has taken the art to a new level by building the headphone drivers from scratch rather than using an off-the-shelf pair.

The result is a set of moving coil drivers with a construction technique involving using the semi-opaque thin window from an envelope as a diaphragm and as a former for the coil. Cyanoacrylate adhesive holds everything in place. The diaphragm is suspended across the mouth of a cardboard tube with the coil positioned above a magnet, resulting in the minimum moving mass necessary for as good a sound reproduction as possible. Judge for yourself, there’s a video that we’ve placed below the break.

The drivers are placed in a set of 3D-printed on-ear holders, and while they probably won’t match an expensive set of commercial headphones, we’d hazard a guess that they won’t have too bad quality. At the very least, it’s an interesting design to base further experimentation on.

Surprisingly few home made speaker or headphone drivers have made it onto these pages, probably because of the ubiquity of the ready-made article. An exception is this flexible PCB speaker, and of course we’ve also talked about home made electrostatic speakers. Continue reading “Make A Set Of Headphones From Scratch” →

The Red Dwarf Talkie Toaster Made Real

February 15, 2020 by Jenny List 18 Comments

It’s cold outside, there’s no kind of atmosphere, you’re all alone, more or less. More or less meaning that you share the gigantic mining ship that is your home on the other side of the galaxy with an ineffectual android, a humanoid descended from your cat, a holographic representation of your dead colleague who’s a complete smeghead, and a really annoying sentient toaster that’s obsessed with bread products. If all this rings a bell, then maybe you’re familiar with the cult BBC TV series, Red Dwarf. It’s a show that evidently [Bill Dudley] has spent too much time watching, because he’s created a really convincing replica of that talking toaster.

The base toaster is a toy appliance with a little clockwork ejector for toy toast, that comes with plenty of space inside and is easy to accessories for the classic Talkie Toaster look. Inside is an off-the-shelf MP3 player board and a home-made PCB which drives a set of LEDs behind the speaker grille in time with the audio. The result won’t make any toast, waffles, or even crumpets, but it will delight any Red Dwarf fans who might be passing, whether someone has smoked them a kipper or not.

Surprisingly this is not the first Talkie Toaster build we’ve seen. If they met, would they have a harmonious conversation about bagels?

Sniffing Signals To Teach Old Speakers New Tricks

February 12, 2020 by Tom Nardi 24 Comments

Like many of the stories you’ll find on these pages, this one starts with a user being annoyed about their device’s inability to perform a simple task. All [Jay Tavares] wanted was for his Bose Cinemate speakers to turn themselves on and off as needed. It seems like a reasonable enough request, and indeed, is exactly the point of HDMI’s Consumer Electronic Control (CEC) feature. But in this case, it would take a bit of custom hardware to get similar functionality.

Unfortunately, the speakers [Jay] has only support optical audio; so any interoperability with HDMI-CEC (hacked or otherwise) was immediately out the window. Still, he reasoned that he should be able to detect when the TOSLINK audio source is actually active or not, and give the speaker system the appropriate signal to either power on or shut down. You might think this would require some kind of separate stand-alone device, but as it turns out, all the necessary information was available by reverse engineering the connection between the receiver and the subwoofer.

After some investigation, [Jay] found that not only was the content of the TOSLINK audio source being sent over this DB9 cable, but so were the control signals required to turn the system on and off. So he designed a simple pass-through device with an ATtiny85 and a couple passives that latches onto the relevant lines in the cable.

When audio is detected over the optical connection, the MCU will inject the appropriate signals on the control line to simulate the user pressing the “Power” button the remote. When the chip hasn’t detected audio after 10 seconds, it sends the signal to shut the speakers off.

While [Jay] notes he can’t guarantee this works on anything other than the particular Bose Cinemate GS Series II system he has, we’d be willing to bet the concept could be adapted to other models or even brands that use a similar cable to link their principle components. If all else fails, you could always add an ESP8266 to your sound system and control it over WiFi.

THAT Preamp

January 25, 2020 by Al Williams 2 Comments

It is easy to cobble together projects these days. ICs make it simple and microcontrollers even easier. However, we always respect a project that really goes from concept to finished product and that’s what we liked about [Curt Yengst’s] “THAT” Thing microphone preamp.

In part 1 of his post about it, he talks about the basic ideas including the chips from THAT — a small but high-end audio chipmaker — he uses. The first chip is a low-noise audio preamp and the other is a balanced line driver.

In part 2, we get to see [Curt] go from breadboard testing to PCB fabrication all the way to the finished rack-mounted device with a good looking front panel. It worked, but like all designers, [Curt] was already thinking about the next version.

Continue reading “THAT Preamp” →

Better Controls For Your Chromecast Through CEC

January 14, 2020 by Lewin Day 34 Comments

Modern home cinema equipment is well-equipped with features for interoperability and convenience, but in practice, competing standards and arcana can make it fall over. Sometimes, you’ve gotta do a little work on your own to glue it all together, and that’s what led [Victor] to develop a little utility of his own.

ChromecastControls is a tool that makes controlling your home cinema easier by improving Chromecast’s integration with the CEC features of HDMI. CEC, or Consumer Electronics Control, is a bidirectional serial bus that is integrated as a part of the HDMI standard. It’s designed to help TVs, audio systems, and other AV hardware to communicate, and allow the user to control an entire home cinema setup with a single remote. Common use cases are TVs that send shutdown commands to attached soundbars when switched off, or Blu-Ray players that switch the TV on to the correct output when the play button is pressed.

[Victor]’s tool allows Chromecast to pass volume commands to surround sound processors, something that normally requires the user to manually adjust their settings with a separate remote. It also sends shutdown commands to the attached TV when Chromecast goes into its idle state, saving energy. It relies on the PyChromecast library to intercept traffic on the network, and thus send the appropriate commands to other hardware. Simply running the code on a Raspberry Pi that’s hooked up to any HDMI port on a relevant device should enable the CEC commands to get through.

It’s a project that you might find handy, particularly if you’re sick of leaving your television on 24 hours a day because Chromecast never bothered to implement a simple CEC command on an idle timeout. CEC hacks have a long history, too – we’ve been covering them as far back as 2010!

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.