AI Listens to Radio

We’ve seen plenty of examples of neural networks listening to speech, reading characters, or identifying images. KickView had a different idea. They wanted to learn to recognize radio signals. Not just any radio signals, but Orthogonal Frequency Division Multiplexing (OFDM) waveforms.

OFDM is a modulation method used by WiFi, cable systems, and many other systems. In particular, they look at an 802.11g signal with a bandwidth of 20 MHz. The question is given a receiver for 802.11g, how can you reliably detect that an 802.11ac signal — up to 160 MHz — is using your channel? To demonstrate the technique they decided to detect 20 MHz signals using a 5 MHz bandwidth.

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Hacking a Sonoff WiFi Switch

The ESP8266 platform has become so popular that it isn’t just being used in hobby and one-off projects anymore. Companies like Sonoff are basing entire home automation product lines around the inexpensive WiFi card. What this means for most of us is that there’s now an easily hackable and readily available product on the market that’s easily reprogrammed and used with tools that we’ve known about for years now, as [Dan] shows in his latest project.

[Dan] has an aquaponics setup in his home, and needs some automation to run the lights. Reaching for a Sonoff was an easy way to get this done, but the out-of-the-box device can only be programmed in the simplest of ways. To get more control over the unit, he wired a USB-to-Serial UART to the female headers on the board and got to programming it.

The upgraded devices are fully programmable and customizable now, and this would be a great hack for anyone looking to get more out of a Sonoff switch. A lot of the work is already done, like building a safe enclosure, wiring it, and getting it to look halfway decent. All that needs to be done is a little bit of programming. Of course, if you’d like to roll out your own home automation setup from scratch that can do everything from opening the garage door to alerting you when your dog barks, that’s doable too. You’ll just need a little more hardware.

Behind the Scenes at a Pair of Cell Sites

Those who fancy themselves as infrastructure nerds find cell sites fascinating. They’re outposts of infrastructure wedged into almost any place that can provide enough elevation to cover whatever gap might exist in a carrier’s coverage map. But they’re usually locked behind imposing doors and fences with signs warning of serious penalty for unauthorized access, and so we usually have to settle for admiring them from afar.

Some folks, like [Mike Fisher] aka [MrMobile], have connections, though, and get to take an up close and personal tour of a couple of cell sites. And while the video below is far from detailed enough to truly satisfy most of the Hackaday crowd, it’s enough to whet the appetite and show off a little of what goes into building out a modern cell site. [Mike] somehow got AT&T to take him up to a cell site mounted in the belfry and steeple of the 178-year old Unitarian Church in Duxbury, Massachusetts. He got to poke around everything from the equipment shack with its fiber backhaul gear and backup power supplies to the fiberglass radome shaped to look like the original steeple that now houses the antennas.

Next he drove up to Mount Washington in New Hampshire, the highest point in the northeast US and home to a lot of wireless infrastructure. Known for having some of the worst weather in the world and with a recent low of -36°F (-38°C) to prove it, Mount Washington is brutal on infrastructure, to which the tattered condition of the microwave backhaul radomes attests.

We appreciate the effort that went into this video, but again, [Mike] leaves us wanting more details. Luckily, we’ve got an article that does just that.

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Espple: A Wireless Apple 1 on an ESP8266

The Apple 1 was one of the three big hobbyist computers that burst onto the scene in 1977. Unlike the PET 2001 and the TRS-80, only a couple hundred Apple 1s were ever produced, and with only a handful in existence today, you’ll have to fork out some serious money to get a Wozniak original for yourself.

The Apple 1 experience is easily emulated, of course, but this ESP8266 emulates the Apple 1 on hard mode. Dubbed the Espple by its creator [Hrvoje Cavrak], it emulates the 6502-based original in all its 1-MHz glory, while providing 20-kB of RAM, a considerable upgrade over the 4-kB standard. The complete original character set is provided for that old-timey feel, and there’s a BASIC interpreter ready to go. The kicker here, though, is that the emulator is completely wireless. You telnet into the 8266 rather than connecting a keyboard directly, and video is transmitted over-the-air using a GPIO pin as a 60-MHz PAL transmitter. A short length of wire is all you need to transmit to an analog PAL TV on channel 4; the video below shows a little BASIC code running and a low-res version of Woz himself.

You’ll find Apple emulators aplenty around these parts, everything from an Apple ][ on an Arduino Uno to a tiny Mac on an ESP32. There hasn’t been much in the way of Apple 1 emulations, though, at least until now.

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A Wireless Webcam Without A Cumbersome Cloud Service

After a friend bought a nannycam that required the use of a cloud service to make the device useful,  [Martin Caarels] thought to himself — as he puts it — ”I can probably do this with a Raspberry Pi!

Altogether, [Caarels] gathered together a 4000mAh battery, a Raspberry Pi 3 with a micro SD card for storage, a Logitech c270 webcam, and the critical component to bind this project together: an elastic band. Once he had downloaded and set up Raspbian Stretch Lite on the SD card, he popped it into the Pi and connected it to the network via a cable. From there, he had to ssh into the Pi to get its IP so he could have it hop onto the WiFi.

Now that he effectively had a wireless webcam, it was time to turn it into a proper security camera.

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Zigbee-Based Wireless Arduinos, Demystified

Hackday regular [Akiba] is working on a series of video tutorials guiding newbies into the world of the 802.15.4 wireless protocol stack — also known as ZigBee. So far, his tutorials include a “getting started with chibiArduino”, his own Arduino-based wireless library, as well as a more basic tutorial on how radio works.

[Akiba] already made a name for himself though a large number of wireless projects, including his Saboten sensor boards, which are ruggedized for long-term environmental monitoring. The Saboten boards use the same wireless stack as his Arduino-compatible wireless development boards, his Freakduino products. The latest version features an ATmega 1284P with 8x the RAM and 4x the flash of the older, 328P-based Freakduinos. It comes in both 900 MHz and 2.4 GHz and there’s also a special 900 Mhz “Long Range” variant. The boards include some great power-saving features, including switchable status LEDs and on-board battery regulation circuity allowing one to run a full year on two AA cells while in sleep mode. They also have a USB stick configuration that is great for Raspberry Pi projects and for running straight from the PC.

For more [Akiba] goodness, check out our colleague [Sophi]’s SuperCon interview with him as well as our coverage of his Puerto Rico lantern project.

Dumb Box? Make it Really Smart!

[Stephen Harrison]’s Really Smart Box is a great concept, it’s simultaneously a simple idea while at the same time being super clever. The Really Smart Box isn’t really a box; it’s a drop-in platform that can be made any size, intended to turn any dumb storage box into one that helps manage and track levels and usage of any sort of stock or consumable.

It does this by measuring the weight of the stuff piled on top of it, while also monitoring temperature and humidity. The platform communicates this information wirelessly to a back end, allowing decisions to be made about stock levels, usage, and monitoring of storage conditions. It’s clearly best applied to consumables or other stock that comes and goes. The Really Smart Box platform is battery-powered, but spends most of its time asleep to maximize battery life. The prototype uses the SigFox IoT framework for the wireless data, which we have seen before in a wireless swimming pool monitor.

This is still just a prototype and there are bugs to iron out, but it works and [Stephen] intends to set-and-forget the prototype into the Cambridge Makespace with the task of storing and monitoring 3D printer filament. A brief demo video is embedded below.

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