The tin can phone is a staple of longitudinal wave demonstrations wherein a human voice vibrates the bottom of a soup can, and compression waves travel along a string to reproduce the speaker in another can at the other end. All the parts in this electrical demonstration are different, but the concept is the same.
Speakers are sound transducers that turn electrical impulses into air vibrations, but they generate electricity when their coil vibrates. Copper wires carry those impulses from one cup to another. We haven’t heard of anyone making a tin can phone amplifier, but the strictly passive route wasn’t working, so an op-amp does some messy boosting. The link and video demonstrate the parts and purposes inside these sound transducers in an approachable way. Each component is constructed in sequence so you can understand what is happening and make sense of the results.
Hardware-wise, both the synth and the amp are fairly simple. Underneath each of those cute little printed keys is one of those clicky momentaries that usually come with bright button caps in primary colors — the keys themselves just press-fit over the tops. All twelve ebonies and ivories are connected up to an Adafruit Feather, which communicates over Bluetooth LE to a CircuitPlayground Bluefruit (CPB) in the amp. Each time a note is played on the synth, its corresponding color circles comet-like around the CPB’s NeoPixels, which shine through the amp’s speaker grille.
The super interesting part is that all the hard work is happening in the code. Both boards have the same array of colors in rainbow order, and the CPB has an array of tone frequencies that match up one for one with the colors. For every note played, the CPB looks up the color, swirls it, and plays the note. If you want to build one, this project is wide open — [Blitz City DIY] even made a learn guide with all the dirty details. Be sure to check out the demo and extended walk-through after the break.
[Tony] posted an interesting video where he looks at the Atari 2600 and the way many companies tried to convert it into a real home computer. This reminded us of the ColecoVision, which started out as a video game but could expand to a pretty reasonable computer.
It might seem silly to convert a relatively anemic Atari video game into a computer, but keep in mind that computers were pretty expensive in those days. Not to mention, the Atari itself was a fair investment back then, too.
The Logitech SqueezeBox was a device you hooked up to your stereo so you could stream music from a Network Attached Storage (NAS) box or your desktop computer over the network. That might not sound very exciting now, but when [Aaron Ciuffo] bought it back in 2006, it was a pretty big deal. The little gadget has been chugging all these years, but the cracks are starting to form. Before it finally heads to that great electronics recycling center in the sky, he’s decided to start work on its replacement.
Thanks to the Raspberry Pi, building a little device to stream digital audio from a NAS is easy these days. But a Pi hooked up to a USB speaker isn’t necessarily a great fit for the living room. [Aaron] didn’t necessarily want his replacement player to actually look like the SqueezeBox, but he wanted it to be presentable. While most of us probably would have tried to make something that looked like a traditional piece of audio gear, he took his design is a somewhat more homey direction.
The Raspberry Pi 4 and HiFiBerry DAC+ Pro live inside of a wooden laser cut case that [Aaron] designed with OpenSCAD. We generally associate this tool with 3D printing, but here he’s exporting each individual panel as an SVG file so they can be cut out. We especially like that he took the time to add all of the internal components to the render so he could be sure everything fit before bringing the design into the corporeal world.
While the case was definitely a step in the right direction, [Aaron] wasn’t done yet. He added a WaveShare e-Paper 5.83″ display and mounted it in a picture frame. Software he’s written for the Raspberry Pi shows the album information and cover art on the display while the music is playing, and the current time and weather forecast when it’s idle. He’s written the software to plug into Logitech’s media player back-end to retain compatibility with the not-quite-dead-yet SqueezeBox, but we imagine the code could be adapted to whatever digital media scheme you’re using.
[Carl] wanted to prototype his circuits quickly using printed circuit boards. He picked up a Bantam Tools Desktop PCB Mill and made a video about the results. His first attempt wasn’t perfect, as you could notice under the microscope. A few adjustments, though, and the result was pretty good.
Be warned, this mill is pretty expensive — anywhere from $2,500 to $3,000. The company claims it is a better choice than a conventional cheap mill because it uses a 26,000 RPM spindle and has high-resolution steppers. Because of its low backlash and high accuracy and repeatability, the company claims it can easily mill boards with 6 mil traces.
I’m sure that you’ve heard about the Sonos speaker debacle. (If not, read about it on Hackaday.) Basically, a company that sells a premium Internet-connected speaker wanted to retire an older product line, and offered a 30% discount to people who would “trade in” their old speakers for new ones. The catch: they weren’t really trading them in, but instead flashing a “self-destruct” firmware and then taking it to the recycling.
Naturally, Sonos’ most loyal customers weren’t happy about intentionally bricking their faithful devices, a hubbub ensued, and eventually the CEO ended up reversing course and eating crow. Hackaday’s own Gerrit Coetzee wrote up our coverage and mentioned that maybe Sonos just couldn’t afford to support the service for the old products any more, and didn’t want them to remain in the wild. So much so, that it’s worth 30% of the cost of their current product to get out from under the implicit contract.
By buying one of these IoT devices, you’re paying more money up front for the promise that the company will keep supporting the service that it relies on into the future. But providing this service costs money, and as more and more “products” are actually services in disguise, we’ve seen case after case of working machines shut down because the company doesn’t want to keep paying for the service. It doesn’t seem to matter if the company is small, like Sonos, or an immensely wealthy monopoly player like Google. Somehow, the people planning these products have a much shorter lifetime in mind than their customers do, and fail to make the up-front price cover costs.
This puts these companies in a tough spot. The more a customer loves the device, the longer they’ll want to keep it running, and the worse the blowback will be when the firm eventually has to try to weasel its way out of a “lifetime” contract. And they are alienating exactly their most loyal customers — those who want to keep their widget running longer than might even be reasonable. Given that this whole business model is new, it’s not surprising that some firms will get it wrong. What’s surprising to me is how many fall into the IoT trap.
So take this as a cautionary tale as a consumer. And if you’re in a company offering a product that depends on a service to continue to function, ask yourself if you’re really going to be able to support it for the customer’s idea of the lifetime of the product. What looks like a great deal at a five-year horizon might bankrupt your company at ten. Will you, or your customers, be willing to throw their devices away? Should they be?
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Last year’s Hackaday Superconference badge was an electronic tour de force, packing an ECP5 FPGA shoehorned into a Game Boy-like form factor and shipping with a RISC-V core installed that together gave an almost infinite badge hacking potential. It did not however run Linux, and that’s something [Greg Davill] has addressed, as he’s not only running Linux on his badge, but also a framebuffer that allows him to use the badge screen as the Linux terminal screen. Finally you can watch Linux boot on your Superconference badge itself, rather than over its serial port.
He’s achieved this by changing essentially everything: from the new VexRiscv CPU core, to new video drivers and a VGA terminal courtesy of Frank Buss, now part of the LiteVideo project. It’s not quite a fully fledged Linux powerhouse yet, but you can find it in a GitHub repository should you have a mind to try it yourself. Paging back through his Twitter feed reveals the effort he’s put into this work over the last few months, and shows that it’s been no easy task.
For those keeping score at home, this is an open hardware design, running an open CPU core, with community-designed open-source peripherals, compiled by an open-source toolchain, running an open-source operating system. And it’s simply a fantastic demo for the badge, showing off how flexible the entire system is. One of the best parts of writing for Hackaday is that our community is capable of a huge breadth of amazing pieces of work, and this is an exemplar of that energy. We can’t wait to see what Greg and any other readers tempted to try it will come up with.