Powering IoT devices is often a question of batteries or mains power, but in rare exceptions to this rule there is no power supply (PDF Warning). At the University of Wisconsin-Madison and the University of California, San Diego, researchers have gone the extra mile to make advanced backscatter devices, and these new tags don’t need the discrete components we have seen in previous versions. They are calling it LiveTag, and it doesn’t need anything aside from a layer of foil printed or etched on a flexible ceramic-PTFE laminate. PTFE is mostly seen in the RF sector as a substrate for circuit boards.
We have seen some of the wild creations with wifi backscatter that range from dials to pushbuttons. RF backscatter works by modulating the RF signals in which we are continuously swimming. Those radio waves power the device and disrupt the ambient signals, which disruption can be detected by a receiver. With a BOM that looks like a statement more than a list, integration with many devices becomes a cost-effective reality. Do not however broadcast important data because you cannot expect great security from backscatter.
[Via IEEE Spectrum]
A few months back we first brought word of the progress being made in unlocking the SMART Response XE, an ATmega128RFA powered handheld computer that allowed teachers to create an interactive curriculum in the days before all the kids got Chromebooks. Featuring 2.4 Ghz wireless communication, a 384×160 LCD, and a full QWERTY keyboard, schools paid around $100 each for them 2010. Now selling for as little as $5 on eBay, these Arduino-compatible devices only need a little coaxing and an external programmer to get your own code running.
The previous post inspired [Larry Bank] to try his hand at hacking the SMART Response XE, and so far he’s made some very impressive progress. Not only has he come up with his own support library, but he’s also created a way to upload Arduino code to the devices through their integrated 802.15.4 radio. With his setup, you no longer need to open the SMART Response XE and attach a programmer, making it much easier to test and deploy software.
[Larry] has written up a very detailed account of his development process, and goes through the trouble of including his ideas that didn’t work. Getting reliable communication between two of these classroom gadgets proved a bit tricky, and it took a bit of circling around until he hit on a protocol that worked.
The trick is that you need to use one SMART Response XE attached to your computer as a “hub” to upload code to other XEs. But given how cheap they are this isn’t that big of a deal, especially considering the boost in productivity it will net you. [Larry] added a 5 x 2 female header to his “hub” XE so he could close the device back up, and also added a physical power switch. In the video after the break, you can see a demonstration of the setup sending a simple program to a nearby XE.
Between this wireless bootloader and the Arduboy compatibility covered previously, we’d suggest you get your SMART Response XE now. We wouldn’t be surprised if the prices of these things start going up like they did with the IM-ME. Continue reading “SMART Response XE Gets Wireless Bootloader”
Thanks to the exploding popularity of First Person View (FPV) RC flying over the last couple of years, the cost of the associated hardware has dropped rapidly. Today you can get entry-level FPV goggles for under $40 USD on various import sites. For the money you’re getting a 5.8 GHz receiver, battery, and an LCD display; even if the components themselves aren’t exactly high end, at that price it’s essentially an impulse buy.
[nomand] didn’t necessarily have a use for a cheap FPV headset, but he did like the idea of having a pocket sized display that he could pass off to others so they could see what he’s seeing during flights. So he harvested the principle components from a Eachine VR006 headset and designed a new 3D printed enclosure for them. The final result looks fantastic, and is much cheaper than commercial alternatives on the market.
He’s created an exceptionally detailed step-by-step guide on how you can perform the conversion yourself in the project’s GitHub repository, and has also put together a video where he goes over the modification and discusses the end result. [nomand] clearly intends for this to be a project for others to duplicate instead of a one-off build, and given the price and final results, we wouldn’t be surprised if this conversion becomes popular in FPV circles.
Perhaps the best part of this project is that it requires almost no modification of the original hardware; just soldering two wires because the original connector is too large. Otherwise just need to take the headset apart carefully, and transplant the components into the 3D-printed case [nomand] has meticulously designed. The case is so well designed it doesn’t even need any fasteners, it slides together and everything is held in with some strategically placed pieces of foam.
Between this modification and the custom built spectator display we covered recently, it looks like there’s a clear demand for sub-$50 portable FPV monitors. Seems odd that no manufacture is trying to fill this niche so far.
Continue reading “Cheap FPV Goggles Turned Pocket Sized Display”
Software defined radio picked up a lot of popularity when it was discovered that cheap USB TV tuners were functional bits of hardware that could become SDRs. It’s the software that makes this possible, and when it comes to SDR software, there’s no better tool than GNU Radio. For this week’s Hack Chat we’re going to sit down with some of the people behind this awesome software tool and pick their brains.
Our guests for this week’s Hack Chat will be Derek Kozel and Nate Temple, officers of the GNU Radio project. They’re also organizers of this year’s GNU Radio Conference. Also joining in on the Hack Chat will be Martin Braun, community manager, PyBOMBS maintainer, and GNU Radio Foundation officer.
GNU Radio is perhaps the most important bit of any software defined radio toolchain. This is the software that provides signal processing blocks to implement software defined radios. GNU radio is how you take a TV tuner USB dongle and pull images from satellites. You can use it for simulation, and GNU Radio is widely used by hobbyists, academics, and by people in industry.
For this week’s Hack Chat, we’re going to be talking all about GNU Radio. What can you do with it? Was the interface really inspired by MaxMSP? All that and more in this week’s Hack Chat.
- Various bits of hardware that make GNU Radio work
- The core process of writing modules
- Upcoming features of GNU Radio
You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the GNU Radio Hack Chat Event Page and we’ll put that in the queue for the Hack Chat discussion.
Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, August 31st. Need a countdown timer? We should look into hosting these countdown timers on hackaday.io, actually.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.
You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.
Many low-cost wireless temperature and humidity sensors use a 433 MHz transmitter to send data back to their base stations. This is a great choice for the manufacturer of said devices because it’s simple and the radios are cheap, but it does limit what we as the consumer can do with it a bit. Generally speaking, you won’t be reading data from these sensors on your computer unless you’ve got an SDR device and some experience with GNU Radio and reading the Nexus protocol.
But [Aquaticus] has developed a very comprehensive piece of software that should make integrating these type of sensors into your home automation system much easier, as long as you’ve got a spare Raspberry Pi lying around. Called nexus433, it uses a cheap 433 MHz receiver connected to the Pi’s GPIO pins to receive data from environmental sensors using the popular Nexus communication protocol. A few known compatible sensors are listed in the project documentation, one of which can be had for as little as $5 USD shipped.
In addition to publishing the temperature, humidity, and battery level values from the sensors to MQTT, it even tracks connection quality for each individual sensor and when they go on and offline. To be sure, this is no simple hack. In nexus433, [Aquaticus] has created a mature Linux service with enough flexibility that you shouldn’t have any problems working it into your automation setup, whether it’s Home Assistant or something you’ve put together yourself.
We’ve seen a number of home automation hacks using these ubiquitous 433 MHz radios, from controlling them with an ESP8266 to hacking a popular TP-LINK router into a low-cost home automation hub.
Over the years, we’ve seen dozens of projects that sell themselves as an ‘Open Source’ cellphone, a hackable cellphone, or some other confabulation of a microcontroller, screen, and a cellular module. The WiPhone is not one of these projects. That’s not to say it’s not an Open Source phone that’s intended to be hackable. No, this is a DIY phone that doesn’t make cellular calls, because this is a phone that only works with SIP and VoIP apps. It’s a WiPhone, and something a lot of us have been waiting for.
The hardware for this WiFi enabled phone is extremely minimal, but there are some interesting tricks up its sleeve. Instead of letting the main microcontroller handle capturing all the button presses, the team behind the WiPhone are using a SN7326 key-scan controller. This cheap part is able to scan 64 buttons, although there are only 25 buttons on the phone. The audio board is a WM8750BL, a cheap codec with a stereo microphone interface and a 400 mW speaker driver. The display is a simple SPI TFT, and apart from the microcontroller, that’s about it.
But it’s the microcontroller that makes it, and for that we turn to the incredible ESP-32. This chip has enough power to play Doom, be a Game Boy, and in this case, make and receive calls from a VoIP provider, scan and connect to WiFi networks, and yes, it can even play snake.
While this is just about the simplest phone you can imagine, and it only works where there’s a WiFi network, a device like this could be invaluable. And really, these days how far are you from a WiFi network you’re already connected to anyway?
When the ESP8266 was released, it was sold as a simple device that would connect to a WiFi network over a UART. It was effectively a WiFi modem for any microcontroller, available for just a few bucks. That in itself is awesome, but then the hackers got their hands on it. It turns out, the ESP8266 is actually a very capable microcontroller as well, and the newest modules have tons of Flash and pins for all your embedded projects.
For [Amine]’s entry to the Hackaday Prize, he’s using the ESP8266 as the ultimate WiFi Swiss Army knife. The Kortex Xttend Lite is a tiny little WiFi repeater that’s capable of doing just about anything with a WiFi network, and with a bit of added hardware, can connect to Ethernet as well.
The hardware on this board sports an ESP8266-07S module, with two free GPIO pins for multiple functions. There’s a USB to UART in there, and a voltage regulator that’s capable of outputting 600mA for the slightly power hungry radio. There’s also an integrated battery management and charge controller, allowing this board to charge an off-the-shelf lithium cell and run for hours without any wires at all.
So, what can this board do? Just about everything you would want for a tiny little WiFi Swiss Army knife. There’s traffic shaping, port mapping, packet sniffing, and even support for mesh networking. There’s also an SMA connector on there, so grab your cantennas — this is a great way to extend a WiFi network, too.
This is a well-designed and well-executed project, and what makes this even more amazing is that this was done as one of [Amine]’s high school projects. Yes, it took about a year to finish this project, but it’s still amazing work for [Amine]’s first ‘high-complexity’ design. That makes it an excellent learning experience, and an awesome entry to this year’s Hackaday Prize.