Orphaned Amazon Dash Buttons Ripe For Hacking

August 5, 2019 by Roger Cheng 35 Comments

Amazon Dash buttons were the ultimate single purpose networked device; it really can’t get much simpler than a push button that sends a single message to a fixed endpoint. It was an experiment in ultimate convenience, an entry point to a connected home, and a target for critics of consumerism excess and technological overkill.

But soon they’ll be little more than a footnote in the history of online shopping, as CNet reports Amazon will take the order system offline at the end of the month. With the loss of their original intended usage, there’s nothing to stop us from hacking any Dash buttons we can get our hands on.

Of course, this decision should come as little surprise. Amazon’s in-home retail point of sale has graduated from these very limited $5 buttons to Alexa-powered voice controlled devices. Many people also carry a cell phone at all times capable of submitting Amazon orders. While there are many good reasons to be skeptical of internet connected appliances, they’re undeniably finding a niche in the market and some have integrated their own version of a Dash button to re-order household supplies.

But are hackers still interested in hacking Dash buttons? Over the lifespan of Amazon Dash buttons, our project landscape has shifted as well. We’re certainly still interested in the guts an Echo Dot. But if we wanted to build a simple networked button, we can use devices like an ESP8266 which are almost as cheap and far easier to use. Using something intended for integration means we don’t have headaches like determining which generation hardware we have.

Despite those barriers, we’ve had many Dash button hacks on these pages. A to-do list updater was the most recent and we doubt it will be the last, especially as Amazon’s deactivation should mean a whole new flood of these buttons will become available for hacking.

[via Ars Technica]

L Band Satellite Antennas Revealed

August 4, 2019 by Al Williams 7 Comments

[SignalsEverywhere] has a lot of satellite antennas and he’s willing to show them off — inside and out — in his latest video that you can see below. Using software-defined radio techniques, you can use these antennas to pull off weather satellite images and other space signals.

A lot of these antennas are actually made for some commercial purpose like keeping ships connected to Inmarsat. In fact, the shipborne antenna has a nice motorized system for pointing the antenna that [SignalsEverywhere] is hoping to modify for his own purposes.

With what appears to be standard NEMA 17 steppers onboard, it should be relatively easy to supplant the original controller with an Arduino and CNC shield. Though considering the resale value these particular units seem to have on eBay, we might be inclined to just roll our own positioner.

The ~~QHF~~ QFH antenna is another interesting teardown. The antenna makes a helix shape and looks like it would be interesting to build from scratch. There isn’t a lot of details about the antenna designs, but it is interesting to see the variety and range of antennas and how they appear internally.

L band is from 1 GHz to 2 GHz, so signals and antennas get very strange at these frequencies. The wavelength of a 2GHz signal is only 15cm, so small antennas can work quite well and are often as much mechanical designs as electrical. The L band contains everything from GPS to phone calls to ADS-B.

We’ve seen radiosonde antennas reborn before. Dish antenna repurposing is also popular.

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Boost Your WiFi Range With Cookware

August 1, 2019 by Lewin Day 44 Comments

WiFi was the killer technology that made home networking easy. No more messing around with hubs and cables and drilling holes in walls, simply turn the devices on and hit connect. Over time the speed and range has increased, but those with larger houses or granny flats out back have suffered. There are tricks to boost range however, and some of them involve cookware.

The clever hack here is to use a metal strainer as a parabolic reflector, to capture signals and focus them onto the PCB antenna in a USB WiFi dongle. The strainer is drilled out, and a USB extension cable has its female end glued into the base. This allows the dongle to be positioned inside the strainer. For best results, the dongle should be positioned so that its antenna elements are sitting at the focal point of the parabola; this can be determined through mathematics or simply by experimenting with positions to see what gives the best signal strength.

It’s a design that is quite directional, and should help boost signals as well as block out those from unwanted stations. The build is simple, and can even be tripod mounted which helps with aiming and looks cool to boot.

For many, WiFi antenna hacks are old school, but it’s always good to keep the techniques in mind as you never know when it will come in handy to solve a new problem. Some crazy things are possible with the right gear, too.

RTL-SDR: Seven Years Later

July 31, 2019 by Tom Nardi 40 Comments

Before swearing my fealty to the Jolly Wrencher, I wrote for several other sites, creating more or less the same sort of content I do now. In fact, the topical overlap was enough that occasionally those articles would get picked up here on Hackaday. One of those articles, which graced the pages of this site a little more than seven years ago, was Getting Started with RTL-SDR. The original linked article has long since disappeared, and the site it was hosted on is now apparently dedicated to Nintendo games, but you can probably get the gist of what it was about from the title alone.

When I wrote that article in 2012, the RTL-SDR project and its community were still in their infancy. It took some real digging to find out which TV tuners based on the Realtek RTL2832U were supported, what adapters you needed to connect more capable antennas, and how to compile all the software necessary to get them listening outside of their advertised frequency range. It wasn’t exactly the most user-friendly experience, and when it was all said and done, you were left largely to your own devices. If you didn’t know how to create your own receivers in GNU Radio, there wasn’t a whole lot you could do other than eavesdrop on hams or tune into local FM broadcasts.

Nearly a decade later, things have changed dramatically. The RTL-SDR hardware and software has itself improved enormously, but perhaps more importantly, the success of the project has kicked off something of a revolution in the software defined radio (SDR) world. Prior to 2012, SDRs were certainly not unobtainable, but they were considerably more expensive. Back then, the most comparable device on the market would have been the FUNcube dongle, a nearly $200 USD receiver that was actually designed for receiving data from CubeSats. Anything cheaper than that was likely to be a kit, and often operated within a narrower range of frequencies.

Today, we would argue that an RTL-SDR receiver is a must-have tool. For the cost of a cheap set of screwdrivers, you can gain access to a world that not so long ago would have been all but hidden to the amateur hacker. Let’s take a closer look at a few obvious ways that everyone’s favorite low-cost SDR has helped free the RF hacking genie from its bottle in the last few years.

Continue reading “RTL-SDR: Seven Years Later” →

Four Years Of Learning ESP8266 Development Went Into This Guide

July 30, 2019 by Bryan Cockfield 20 Comments

The ESP8266 is a great processor for a lot of projects needing a small microcontroller and Wi-Fi, all for a reasonable price and in some pretty small form factors. [Simon] used one to build a garage door opener. This project isn’t really about his garage door opener based on a cheap WiFi-enabled chip, though. It’s about the four year process he went through to learn how to develop on these chips, and luckily he wrote a guide that anyone can use so that we don’t make the same mistakes he did.

The guide starts by suggesting which specific products are the easiest to use, and then moves on to some “best practices” for using these devices (with which we can’t argue much), before going through some example code. The most valuable parts of this guide especially for anyone starting out with these chips are the section which details how to get the web server up and running, and the best practices for developing HTML code for the tiny device (hint: develop somewhere else).

[Simon] also makes extensive use of the Chrome developers tools when building the HTML for the ESP. This is a handy trick even outside of ESP8266 development which might be useful for other tasks as well. Even though most of the guide won’t be new to anyone with experience with these boards, there are a few gems within it like this one that might help in other unrelated projects. It’s a good read and goes into a lot of detail about more than just the ESP chips. If you just want to open your garage door, though, you have lots of options.

Teardown: Catel CTP300 Restaurant Pager

July 30, 2019 by Tom Nardi 39 Comments

I have a problem. If I go to a swap meet , or even a particularly well stocked yard sale, I feel compelled to buy something. Especially if that something happens to be an oddball piece of electronics. While on the whole I’m a man of few vices, I simply can’t walk away from a good deal; doubly so if it has a bunch of buttons, LEDs, and antennas on it.

Which is exactly how I came into the possession of a Catel CPT300 restaurant paging system for just $20 a few months ago. I do not, as you may have guessed, operate a restaurant. In fact, as many of my meals take the form of military rations eaten in front of my computer, I’m about as far away from a restaurateur as is humanly possible. But I was so enamored with the rows of little plastic pagers neatly lined up in their combination charging dock and base station that I had to have it.

The man selling it swore the system worked perfectly. Even more so after he plugged it in and it didn’t do anything. But appearances can be deceiving, and his assurance that all the pagers needed was a good charge before they’d burst back to life seemed reasonable enough to me. Of course, it hardly mattered. The regular Hackaday reader at this point knows the fate of the CPT300 was to be the same whether or not it worked.

Incidentally, those cute little pagers would not burst back to life with a good charge. They may well have burst into something, but we’ll get to that in a moment. For now, let’s take a look at a gadget that most of us have used at one time or another, but few have had the opportunity to dissect.

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Fail Of The Week: The Arduino Walkie That Won’t Talkie

July 28, 2019 by Dan Maloney 33 Comments

There’s something seriously wrong with the Arduino walkie-talkie that [GreatScott!] built.

The idea is simple: build a wireless intercom so a group of motor scooter riders can talk in real-time. Yes, such products exist commercially, but that’s no fun at all. With a little ingenuity and a well-stocked parts bin, such a device should be easy to build on the cheap, right?

Apparently not. [GreatScott!] went with an Arduino-based design, partly due to familiarity with the microcontroller but also because it made the RF part of the project seemingly easier due to cheap and easily available nRF24 2.4 GHz audio streaming modules. Everything seems straightforward enough on the breadboard – an op-amp to boost the signal from the condenser mic, a somewhat low but presumably usable 16 kHz sampling rate for the ADC. The radio modules linked up, but the audio quality was heavily distorted.

[GreatScott!] assumed that the rat’s nest of jumpers on the breadboard was to blame, so he jumped right to a PCB build. It’s a logical step, but it seems like it might be where he went wrong, because the PCB version was even worse. We’d perhaps have isolated the issue with the breadboard circuit first; did the distortion come from the audio stage? Or perhaps did the digitization inject some distortion? Or could the distortion be coming from the RF stage? We’d want to answer a few questions like that before jumping to a final design.

We love that [GreatScott!] has no issue with posting his failures – we’ve covered his suboptimal CPU handwarmer, and his 3D-printed BLDC motor stator was a flop too. It’s always nice to post mortem these things to avoid a similar fate.

Continue reading “Fail Of The Week: The Arduino Walkie That Won’t Talkie” →