Hackaday Prize Entry: A Modular Open-Source AV Receiver

Hi-Fi hasn’t changed much in decades. OK, we’ll concede that’s something of a controversial statement to make in that of course your home hi-fi has changed immensely over the years. Where once you might have had a turntable and a cassette deck you probably now have a streaming media player, and a surround sound processor, for example.

But it’s still safe to say that hi-fi reproduction hasn’t changed much in decades. You can still hook up the latest audio source to an amplifier and speakers made decades ago, and you’ll still enjoy great sound.

Not so though, if instead of a traditional amplifier you bought an AV receiver with built-in amplifier and processing. This is a fast-moving corner of the consumer electronics world, and the lifetime of a device before its interfaces and functionality becomes obsolete can often be measured in only a few years.

To [Andrew Bolin], this makes little sense. His solution has some merit, he’s produced a modular open-source AV processor in which the emphasis is on upgradeability to keep up with future developments rather than on presenting a black box to the user which will one day be rendered useless by the passage of time.

His design revolves around a backplane which accepts daughter cards for individual functions, and a Raspberry Pi to do the computational heavy lifting. So far he has made a proof-of-concept which takes in HDMI audio and outputs S/PDIF audio to his DAC, but plans are in hand for further modules. We can see that this could become the hub of a very useful open-source home entertainment system.

If you make one, please remember to enhance it with our own sound-improving accessory.

Hackaday Prize Entry: A PC-XT Clone Powered By AVR

There is a high probability that the device on which you are reading this comes somehow loosely under the broad definition of a PC. The familiar x86 architecture with peripheral standards has trounced all its competitors over the years, to the extent that it is only in the mobile and tablet space of personal computing that it has not become dominant.

The modern PC with its multi-core processor and 64-bit instruction set is a world away from its 16-bit ancestor from the early 1980s. Those early PCs were computers in the manner of the day, in which there were relatively few peripherals, and the microprocessor bus was exposed almost directly rather than through the abstractions and gatekeepers we’d expect to see today. The 8088 processor with an 8-bit external bus though is the primordial PC processor, and within reason you will find software written for DOS on those earliest IBM machines will often still run on your multiprocessor behemoth over a DOS-like layer on your present-day operating system. This 35-year-plus chain of mostly unbroken compatibility is both a remarkable feat of engineering and a millstone round the necks of modern PC hardware and OS developers.

Those early PCs have captured the attention of [esot.eric], who has come up with the interesting project of interfacing an AVR microcontroller to the 8088 system bus of one of those early PCs. Thus all those PC peripherals could be made to run under the control of something a little more up-to-date. When you consider that the 8088 ran at a modest 300KIPS and that the AVR is capable of running at a by comparison blisteringly fast 22MIPS, the idea was that it should be able to emulate an 8088 at the same speed as an original, if not faster. His progress makes for a long and fascinating read, so far he has accessed the PC’s 640KB of RAM reliably, talked to an ISA-bus parallel port, and made a CGA card produce colours and characters. Interestingly the AVR has the potential for speed enhancements not possible with an 8088, for example it can use its own internal UART with many fewer instructions than it would use to access the PC UART, and its internal Flash memory can contain the PC BIOS and read it a huge amount faster than a real BIOS ROM could be on real PC hardware.

In case you were wondering what use an 8088 PC could be put to, take a look at this impressive demo. Don’t have one yourself? Build one.

Hackaday Prize Entry: Device for Seismic Noise Analysis

Whenever there is an earthquake somewhere in the world, our TV screens fill with images of seismic data. Those news report graphics with simplified bite-sized diagrams that inform the masses, but usually get something wrong. Among the images there will invariably be one of a chart recorder drawing a significant earthquake trace on paper, which makes good TV, but is probably miles away from the state of the art in seismology.

We are not seismologists here at Hackaday, so it was extremely interesting to find [Michael D]’s project, Device for Seismic Noise Analysis. In it, he gives a basic primer in seismic sensors, and outlines his take on the subject, a sensitive wideband seismic sensor designed to capture the seismic background noise. It seems that many seismic sensors are designed to capture big events, yet ignore the noise between them from which using suitable software one can glean advance warning of seismic events.

The sensor is a simple design, a ball of significant mass rests upon three piezoelectric microphone elements spaced at 120 degree intervals. An extremely high impedance op-amp circuit converts and integrates the charge from the piezo element to a voltage that can be read by an Arduino Yun which harvests the data. It is a bold claim, but the device is said to have already given advance warning of minor seismic events near its Tennessee test site.

Seismology has featured here a few times before. There was this seismometer using a subwoofer as its sensor, and this project using commercial geophones, just to name a couple of examples.

Don’t Forget: Bring a Hack Munich is Tonight

If you’re in Munich, Germany this weekend and you’ve got a sweet hack to show off and a thirst for beer and/or good geeky company, then you’re in luck! Come join Hackaday at the muCCC for a Hackaday Prize Bring a Hack.

The location is Schleißheimer Str. 41, a short walk west along Heßstraße from the Theresienstraße U-Bahn. No reservation is needed, but it’d be swell if you’d let us know in the comments that you’re coming (or better yet, click the “join this event” button in the upper right of the event page) so that we have enough pizza on hand.

The party starts at 20:00, not entirely coincidentally as soon as exhibitor setup at Make Munich closes. So if you’re setting up a booth, come on over to the other side of town where you can show off a small project to a select audience of fellow hackers. If you’re only going to be attending Make Munich, this is a great warm up.

Hackaday’s [Elliot Williams] will be there and taking photos if you’ve got something portable that you’d like to show the world! Otherwise, relax and hang out with kindred spirits. Need a time and place to get a team together for the Hackaday Prize? Here, with beer! (Or Spezi, but nothing rhymes with Spezi.)

Many thanks again to our hosts at Munich’s CCC.

Hackaday Prize Entry: Arduino Splash Resistant Toilet Foamer

There are some universal human experiences we don’t talk about much, at least not in public. One of them you’ll have in your own house, and such is our reluctance to talk about it, we’ve surrounded it in a fog of euphemisms and slang words. Your toilet, lavatory, john, dunny, khazi, bog, or whatever you call it, is part of your everyday life.

For his Hackaday Prize entry, [VijeMiller] tackles his smallest room head-on. You see, for him, the chief horror of the experience lies with the dreaded splashback. Yes, a bit of projectile power dumping leaves the old rump a little on the damp side. So he’s tackled the problem with some maker ingenuity and installed an Arduino-controlled foam generator that injects a mixture of soap and glycerin to fill the bowl with a splash-damping load of foam. Rearward inundation avoided.

The parts list reveals that the foam is generated by a fish tank aerator, triggered by a relay which is driven by an Arduino Uno through a power transistor. A solenoid valve controls the flow, and a lot of vinyl tubing hooks it all together. There is an HC/06 Bluetooth module with an app to control the device from a phone, though while he’s posted some Arduino code there is no link to the app. There are several pictures, including a cheeky placement of a Jolly Wrencher, and a shot of what we can only surmise is a text, as foam overflows all over the bathroom. And he’s put up the video we’ve placed below the break, for a humorous demonstration of the device in action.

Continue reading “Hackaday Prize Entry: Arduino Splash Resistant Toilet Foamer”

Friday Hack Chat: Chip Gracey from Parallax

Learn the ins and outs of multi-core microcontrollers as Chip Gracey leads this week’s Hack Chat on Friday 5/5 at noon PDT. Chip founded Parallax and has now been working for more than a decade on the Propeller 2 design, a microcontroller which has 8 and 16 core options.

When it comes to embedded development, most people think of a single process running. Doing more than one task at a time is an illusion provided by interrupts that stop one part of your program to spend a few cycles on another part before returning. The Propeller 2 has true parallel processing; each core can run its own part of the program. From the embedded engineer’s perspective that makes multiple real-time operations possible. Where things get really interesting is how those cores work together.

Here’s your chance to hear about multi-core embedded first hand, from both the silicon design side and the firmware developer side. Join us for a Parallax Hack Chat this Friday at noon PDT.

Here’s How To Take Part:

join-hack-chatOur Hack Chats are live community events on the Hackaday.io Hack Chat group messaging.

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Hackaday Prize Entry: Hacker Calculus

Mathematics, as it is taught in schools, sometimes falls short in its mission to educate the pupils. This is the view of [Joan Horvath] and [Rich Cameron], particularly with respect to the teaching of calculus, which they feel has become a purely algebraic discipline that leaves many students in the cold when it comes to understanding the concepts behind it.

Their Hacker Calculus project aims to address this, by returning to [Isaac Newton]’s 1687 seminal work on the matter, Philosophiae Naturalis Principia Mathematica. They were struck by how much the Principia was a work of geometry rather than algebra, and they are seeking to return to [Newton]’s principles in a bid to make the subject more accessible to students left behind when it comes to derivatives and integrals. They intend to refine the geometric approach to create a series of practical items to explain the concepts, both through 3D printed items and through electronics.

We can see that this is an approach that has considerable merit, given that most Hackaday readers will have at some time or other sat through a maths lesson and come away wondering what on earth the teacher was talking about and having been baffled by further attempts to explain it through impenetrable maths-speak. If you were the kid who “got” calculus when the relationship between speed and acceleration – another thing we have [Newton] to thank for describing – was explained in your physics lessons, then you will probably understand.

The pair have some Hackaday Prize history, you may remember them from such previous entries as their 3D prints for the visually impaired project from last year.