If you watch old science fiction or military movies — or if you were alive back in the 1960s — you probably know the cliche for a radar antenna is a spinning dish. Although the very first radar antennas were made from wire, as radar sets moved higher in frequency, antennas got smaller and rotating them meant you could “look” in different directions. When most people got their TV with an antenna, rotating those were pretty common, too. But these days you don’t see many moving antennas. Why? Because antennas these days move electrically rather than physically using multiple antennas in a phased array. These electronically scanned phased array antennas are the subject of Hunter Scott’s talk at 2018’s Supercon. Didn’t make it? No problem, you can watch the video below.
While this seems like new technology, it actually dates back to 1905. Karl Braun fed the output of a transmitter to three monopoles set up as a triangle. One antenna had a 90 degree phase shift. The two in-phase antennas caused a stronger signal in one direction, while the out-of-phase antenna canceled most of the signal and the resulting aggregate was a unidirectional beam. By changing the antenna fed with the delay, the beam could rotate in three 120 degree steps.
Today phased arrays are in all sorts of radio equipment from broadcast radio transmitters to WiFi routers and 5G phones. The technique even has uses in optics and acoustics.
Continue reading “No Moving Parts: Phased Array Antennas Move While Standing Still”
There’s wealth of activities at the Hackaday Superconference but we’ve saved a few for today’s announcement that will inspire you to take on something new and different. Check out the eight talks below that will push you to try the unexpected, to look at old things in a new way, and to propel your hardware adventures for another year.
This is the Ultimate Hardware Conference and you need to be there! We’ll continue to announce speakers and workshops as final confirmations come in. Supercon will sell out so grab your ticket now before it’s too late.
Ultra Low Cost, Low Power, Low Weight, Light-up Mesh Networkings
How to “float” a mesh network with light-up balloons in the air without re-powering.
Building Motors from PCBs
Ongoing design and prototyping experiments that use Printed Circuit Boards (either rigid or flexible) as a coil in conjunction with rare earth magnets to create interesting motors and actuators.
Joan Horvath and Rich Cameron
Travel back to Isaac Newton’s work to rethink calculus and make it intuitive using 3D printed open-source designs.
Making it Matter for Developing Countries
Building hardware in support of foreign aid projects. Learn what considerations really matter when designing for developing country contexts.
RF engineers put great effort into crafting high quality radio systems. I am not one of those engineers. Experimenting with radio protocols using SDR.
Connect the Dots; Choices Make a Life
How does life unfold if you create things? Nothing created is wasted — following your dreams will lead you somewhere (maybe not where you planned), but to a good place. How I quit my engineering job and built interesting things as a career.
Why Phased Arrays Are Cool and How to Build One
At the intersection of the two black arts of RF engineering and antenna design is the phased array. But don’t worry, they’re not as hard to understand as you might think.
Small Scale Vacuum Tube Construction
Showing the process for the construction of vacuum tubes. Tubes will be built and tested on site using glass working torches and other specialized tools
We Want You at Supercon!
The Hackaday Superconference is a can’t-miss event for hardware hackers everywhere. Join in on three amazing days of talks and workshops focusing on hardware creation. This is your community of hardware hackers who congregate to hack on the official hardware badge and on a slew of other projects that show up for the fun. Get your ticket right away!
One of the most interesting facets of our community of hackers and makers comes from its never-ending capacity to experiment and to deliver new technologies and techniques. Ample demonstration of this came this morning, in the form of [Hunter Scott]’s Hackaday.io project to create an ultrasonic soldering iron. This is a soldering technique in which the iron is subjected to ultrasonic vibrations which cavitate the surface of the materials to be soldered and remove any oxides which would impede the adhesion of the solder. In this way normally unsolderable materials such as stainless steel, aluminium, ceramic, or glass can be soldered without the need for flux or other specialist chemicals. Ultrasonic soldering has been an expensive business, and [Hunter]’s project aims to change that.
This iron takes the element and tip from a conventional mains-powered soldering iron and mounts it on the transducer from an ultrasonic cleaner. The transducer must be given an appropriate load which in the case of the cleaner is furnished by a water bath, or it will overheat and burn out. [Hunter]’s load is just a soldering iron element, so to prevent transducer meltdown he keeps the element powered continuously but the transducer on a momentary-action switch to ensure it only runs for the short time he’s soldering. The project is not quite finished so he’s yet to prove whether this approach will save his transducer, but we feel it’s an interesting enough idea to make it definitely worth following.
This is the first ultrasonic soldering project we’ve featured here at Hackaday. We have however had an ultrasonic plastic welder before, and an ultrasonic vapour polisher for 3D prints. It would be good to think this project could spark a raft of others that improve and refine DIY ultrasonic soldering designs.
A lot of young athletes who get concussions each year go undiagnosed, leading to brain injury. [Hunter Scott] is working on a device called Impact to help detect these events early. According to this article which discusses the issue of concussion recognition and evaluation, “Early identification on the sports sideline of suspected concussion is critical because, in most cases, athletes who are immediately removed from contact or collision sports after suffering a concussion or other traumatic brain injury will recover without incident fairly quickly. If an athlete is allowed to keep playing, however, their recovery is likely to take longer, and they are at increased risk of long-term problems”
The device is a dime sized disk, which has an ATTiny85 microcontroller, memory to hold data, an accelerometer and a LED which gets activated when the preset impact threshold is breached, all driven by a coin cell. This small size allows it to be easily embedded in sports equipment such as helmets. At the end of a game, if the LED is blinking, the player is then screened for a concussion. For additional analysis, data stored on the on-board memory can be downloaded. This can be done by a pogo-pin based docking station, which is what [Hunter Scott] is still working on.
He’s having a functional problem that needs fixing. The ATTiny85 cannot be programmed with the accelerometer populated. He first needs to populate the ATTiny85, program it, and then populate the accelerometer. He’s working in fixing that, but if you have any suggestions, chime in on the comments below. We’d like to add that [Hunter] is a prolific hacker. His project, the Ultra-wideband radio module was a Hackaday Prize semi-finalist last year.
When you start looking into the Internet of Things, the first thing you realize is that despite there being grand ideas for Internet connected everything, nobody knows how these things will actually connect to the Internet. There are hundreds of different radio protocols being pushed, and dozens of networking schemes currently in development. The solution to this is a radio module that can do them all, talking to all these modules and serving them up to the Internet. This is the idea of [Hunter Scott]’s Level, a radio module with a frequency range of 30 MHz to 4.4 GHz. That’ll cover just about everything, including some interesting applications in the TV whitespace.
[Hunter]’s module is based around TI’s CC430, basically an MSP430 microcontroller and a CC1101 transceiver smooshed together into a single piece of silicon. There’s bit of filtering that makes this usable in the now sorta-empty TV whitespace spectrum, something that a lot of IoT and wireless networking protocols are looking at.
If the form factor of the device looks familiar, that’s because it is; the board itself is Arduino compatible, but not with Arduinos themselves; it will accept shields, though, meaning building a bridge to Ethernet or WiFi to whatever radios this board is talking to is really just a change in firmware.
This board is excellent for experimenting with different radio modules, yes, but it’s also great for experimenting with different radio protocols. [Hunter] has been looking around at different mesh networking protocols.
You can check out [Hunter]’s two minute video overview, along with a more detailed overview of the schematic below.
The project featured in this post is a semifinalist in The Hackaday Prize.
Continue reading “THP Semifinalist: Level, The Ultrawideband Radio Module”
Not being a coffee drinker [Hunter Scott] wanted a way to make tea while lurking in his workshop. Well it’s not exactly rocket science, as all you need is water at the right temperature and a vessel in which the tea can be steeped. But we do commend him on not only building a nice little hot plate enclosure, but rolling a magnetic stirrer into the other side of the box.
You heard us right, the stirrer is not combined with the plate, but resides on the underside of the same PSU enclosure. The plate itself is from a unit he bought at the store and cannibalized. The light switch dimmer lets him adjust the heat it puts out. When not hot, he can flip it over and use the stir plate. This consists of a hard drive magnet attached to a PC fan. For the stirrer itself he encased a neodymium magnet in some thermoplastic. The magnetic combination works well together with a demonstration which shows it stirring water through the base of a tea-cup.
Sure, [Hunter Scott’s] Breathalyzer can only differentiate between hammer and sober, but look how nice it came out. He’s using an MQ-3 alcohol sensor which, from previous projects, we know is very difficult to accurately calibrate. But if you want to monkey around with embedded systems you’ve got to have a goal. [Hunter] chose a gorgeous aluminum project enclosure, adding a big LCD display to the to the lit. The switch on the bottom selects between on, off, and charging modes. He’s using a USB charger from Adafruit to top off the lithium battery inside. Everything runs on 3.3V with the exception of the sensor which gets its 5V supply from a boost converter. An Arduino is the brains that pulls everything together.
See [Hunter’s] video description of the project embedded after the break.
Continue reading “Inaccurate Breathalyzer Is Still Quite Nice”