Year: 2018

Build A Wi-Fi Smart Scale

July 23, 2018 by 10 Comments

There are plenty of ways to monitor changes in your weight. You can get a vague idea from the fit of your pants or the notch on your belt. But anyone who’s serious about getting or staying in shape must step on the scale to get the cold, hard truth in pounds or kilograms.

Instead of just buying one, [igorfonseca83] decided to burn a few calories and build his own smart scale that uses IFTTT to send weight data to his fitness tracker. It’s made from four 50kg load cells that are sandwiched between two pieces of plywood. An HX711 sensor module reads the load cells, and a FireBeetle ESP8266 uploads the data to Adafruit IO. His weight is simultaneously displayed on a FireBeetle LED matrix.

We applaud [igorfonseca83]’s efforts to make this an easy, educational project that anyone can replicate. The instructions are great, the pictures are clear, and there’s even a CAD animation of all the pieces coming together. Jog past the break to see the build video, and weigh in down below.

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HOPE XII: Time Travel With Software Defined Radio

July 23, 2018 by 51 Comments

It’s easy to dismiss radio as little more than background noise while we drive.  At worst you might even think it’s just another method for advertisers to peddle their wares. But in reality it’s a snapshot of the culture of a particular time and place; a record of what was in the news, what music was popular, what the weather was like, basically what life was like. If it was important enough to be worth the expense and complexity of broadcasting it on the radio, it’s probably worth keeping for future reference.

But radio is fleeting, a 24/7 stream of content that’s never exactly the same twice. Yet while we obsessively document music and video, nobody’s bothering to record radio. You can easily hop online and watch a TV show that originally aired 50 years ago, but good luck finding a recording of what your local radio station was broadcasting last week. All that information, that rich tapestry of life, is gone and there’s nothing we can do about it.

Or can we? At HOPE XII, Thomas Witherspoon gave a talk called “Creating a Radio Time Machine: Software-Defined Radios and Time-Shifted Recordings”, an overview of the work he’s been doing recording and cataloging the broadcast radio spectrum. He demonstrated how anyone can use low cost SDR hardware to record, and later play back, whole chunks of the AM and shortwave bands. Rather than an audio file containing a single radio station, the method he describes allows you to interactively tune in to different stations and explore the airwaves as if it were live.

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Turn A Cheap Bluetooth Speaker Into An Audio Receiver

July 23, 2018 by 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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Hands On With Python 3.7: What’s New In The Latest Release

July 23, 2018 by 42 Comments

Used for general purpose programming, data science, website backends, GUIs, and pretty much everything else; the first programming language for many, and claimed to be the fastest growing in the world, is of course Python. The newest version 3.7.0 has just recently been released.
Naturally any release of Python, no matter how small, undergoes meticulous planning and design before any development is started at all. In fact, you can read the PEP (Python Enhancement Proposal) for Python 3.7, which was created back in 2016.

What’s new in 3.7? Why should you upgrade? Is there anything new that’s actually useful? I’ll answer these questions for you by walking through some examples of the new features. Whilst there’s not much in this release that will make a difference to the Python beginner, there’s plenty of small changes for seasoned coders and a few headline features you’ll want to know about.

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Fail Of The Week: ESP Walkie, Not-So-Talkie

July 23, 2018 by 51 Comments

The ESP8266 has become such a staple of projects in our community since it burst onto the scene a few years ago. The combination of a super-fast processor and wireless networking all on the same chip and sold in retail quantities for relative pennies has been irresistible. So when [Petteri Aimonen] needed to make a wireless intercom system for cycling trips it seemed an obvious choice. Push its internal ADC to sample at a high enogh rate for audio, and stream the result over an ad-hoc wi-fi network.

The result was far from satisfactory, as while early results with a signal generator seemed good, in practice it was unusable. Significant amounts of noise were entering the pathway such that the resulting audio was unintelligible. It seems that running a wireless network causes abrupt and very short spikes of power supply current that play havoc with audio ADCs.

He’s submitted it to us as a Fail Of The Week and he’s right, it is a fail. But in a way that’s an unfair description, because we can see there is the germ of a seriously good idea in there. Perhaps with an external ADC, or maybe with some as-yet-to-be-determined filtering scheme, an ESP8266 walkie-talkie is one of those ideas that should be taken to its conclusion. We hope he perseveres.

The Return Of RadioShack?

July 23, 2018 by 119 Comments

We’ve been following the ups and downs of Radio Shack for a while now, and it looks like another chapter is about to be penned in the storied retailer’s biography – and not Chapter 11 bankruptcy this time.

According to the ARRL website and major media reports, up to 50 of the 147 US locations of HobbyTown, the brick-and-mortar retailer of RC and other hobby supplies, will soon host a “RadioShack Express” outlet. Each outlet will be up to 500 square feet of retail space devoted to electronic components that would be of use to HobbyTown’s core customer base, as well as other merchandise and services.

HobbyTown locations in Mooresville, North Carolina, and Ontario, Ohio, will be among the first stores to get the RadioShack Express treatment. Current employees of the franchisees will staff the store-within-a-store, which will be stocked with RadioShack merchandise purchased by the store. Stores with Express outlets will have special RadioShack branding inside and out to attract customers. There’s talk of the deal being extended chain-wide if the pilot program goes well.

Back from the Ashes?

This is obviously great news for the beleaguered electronics retailer that was once a neighborhood fixture. True, its parts selection was often less than complete, more so in recent years than in the chain’s heyday in the mid-1970s and early 1980s. And it’s true that prices were often astronomical compared to buying online. But on a Sunday afternoon, The Shack was a lifesaver for that last minute part needed to finish a project, and the premium was well worth the convenience. Watching the decline of the chain and seeing stores disappear one by one was a slow, sad process, so that makes this seems like an unqualified positive development.

But is it? On the face of it, there’s a lot of synergy between the HobbyTown offerings and what could be stocked in a RadioShack Express. I’ve never actually visited a HobbyTown myself — I plan to fix that now that I know I’ve got an outlet nearby, even if it doesn’t appear to be on the list of 50 early Express locations — so I can only go by what I see listed online for merchandise. But a store that sells every conceivable part for RC cars and planes, drones, model rockets, and STEM-related toys and kits seems a likely place to find customers for RadioShack’s offerings.

It won’t be clear until someone sees one of these Express kiosks first hand and reports back, but it seems like we might see something like the old “cabinet o’ components” that was found in the back of the most recent incarnation of RadioShack retail stores, along with a few shelves full of things like solder, wire, and tools. There may also be some items in the Arduino-Pi space, which would be really exciting, although that might run afoul of existing HobbyTown offerings. Still, one-stop shopping of everything from servos to MOSFETs would be a huge win for electronics hobbyists.

Not the Cell Phones Again!

But there may be cause for concern. Reports are that RadioShack Express locations will also offer services such as cell phone repairs. Dipping a toe into the cell phone market seemed to be the beginning of the end for RadioShack the first time through, and by the time it was clear to everyone that the chain was on death’s door, it was hard to go into a RadioShack store without being bombarded by cell phone sales pitches. To be brutally frank, I don’t take the early inclusion of cell phone repairs as an encouraging sign of the long-term viability of the RadioShack Express concept. Do we really need another place that fixes cell phones? The areas that HobbyTown stores tend to locate are rife with places that fix phones already, so I just don’t see the point. And it just smacks of the bad old days of RadioShack.

Still, I’m cautiously optimistic that this is a positive development for RadioShack, and I think it’s a win for electronics hobbyists overall. I’ll be keeping my eye on my local HobbyTown for the return of that iconic RadioShack logo, and looking forward to the day that I can pay a buck for a resistor again. Until then, if any readers happen to be near one of the combined locations when they open next week, we’d love a boots-on-the-ground report. Post your observations in the comments below, and pix or it didn’t happen.

[via r/amateurradio]

IHC Badge: It’s Not (Quite) A Nokia

July 22, 2018 by 16 Comments

Electronic conference badges are an integral part of our culture, and have featured many times here. The norm for a badge is an exquisitely designed printed circuit board with some kind of microcontroller circuit on it, often a display, and some LEDs.

This is not enough though for [Mastro Gippo], for he has given us an interesting alternative, the shell of a Nokia 3310 mobile phone fitted with a new motherboard holding an ESP32 module, and of course that classic display. It is to be the badge for IHC Camp, which initialism if you hadn’t guessed stands for Italian Hacker Camp, and which will run from the 2nd to the 5th of August 2018 in Padova, Italy. It’s worth reminding readers, at the time of writing IHC tickets are still available, so get ’em while they’re hot!

The board itself is a beautiful piece of work, and aside from the Nokia’s keyboard and display it holds the ESP module and an STM32F103 microcontroller that handles all the peripherals. There is no microphone, after all this is a badge rather than a phone, but there is space for a LoRa module. He’s done another fascinating post about the PCB design, including the on-board wireless antenna.

We have seen a lot about badges from the #BadgeLife scene surrounding the USA’s DEFCON courtesy of our colleague [Brian Benchoff], so it is particularly interesting to see badges from the opposite side of the Atlantic. This is an artform whose journey still has a way to go, and we’ll be along for the ride!