Phased array antenna systems are at the cusp of ubiquity. We now see Multiple-Input Multiple-Output (MIMO) antenna systems on WiFi routers. Soon phased array weather radar systems will help to predict the weather and keep air travel safe, and phased array base stations will be the backbone of 5G which is the next generation of wireless data communication. But what is a phased array antenna system? How do they work? With the help of 1024 LEDs we’ll show you.
How much effort do you put into conserving energy throughout your daily routine? Diligence in keeping lights and appliances turned off are great steps, but those selfsame appliances likely still draw power when not in use. Seeing the potential to reduce energy wasted by TVs in standby mode, the [Electrical Energy Management Lab] team out of the University of Bristol have designed a television that uses no power in standby mode.
The feat is accomplished through the use of a chip designed to activate at currents as low as 20 picoamps. It, and a series of five photodiodes, is mounted in a receiver which attaches to the TV. The receiver picks up the slight infrared pulse from the remote, inducing a slight current in the receiving photodiodes, providing enough power to the chip which in turn flips the switch to turn on the TV. A filter prevents ambient light from activating the receiver, and while the display appears to take a few seconds longer to turn on than an unmodified TV, that seems a fair trade off if you aren’t turning it on and off every few minutes.
[JC Sheitan Tenet] lost his right arm when he was 10 years old. As most of us, he was right-handed, so the challenges he had to face by not having an arm become even harder.
Have you ever tried to perform mundane tasks with your non-dominant hand? If you’re right-handed, have you ever tried to feed yourself with your left? Or if you’re left-handed, how well can you write with your right? For some people, using both hands comes naturally, but if you’re anything like me, your non-dominant hand is just about useless.
The thing is, he wanted to be a tattoo artist. And he wasn’t giving up. Even facing the added difficulty of not finding a tattoo artist that wanted to take him as an apprentice, he did not gave up. So he became a tattoo artist, using only his left arm. That is, until some months ago, when he met [Jean-Louis Gonzal], a bio-mechanical artist with an engineer background, at a tattoo convention. After seeing [Gonzal] work, he just asked if it was possible to modify a prosthesis and attach a tattoo machine to it.
The Cyborg Artist is born. The tattoo machine in the prosthesis can move 360 degrees for a wide range of movements. [JC Sheitan Tenet] uses it to help with colours, shadows and abstract forms in general. It’s a bad-ass steam punk prosthesis and it’s not just for show, he actually works with it (although not exclusively) . This, it seems, is only the beginning, since the first version of prototype worked so well, the second version is already being planned by [JC] and [Gonzal]. We can’t wait to see what they’ll come up with, maybe a mix between current version and a tattoo robotic arm or a brain controlled needle?
Check it out in the video:
If you want to measure humidity (and temperature, and maybe even barometric pressure) in a device that you’re building, have a look at this comprehensive test of seven different options. We’re going to summarize the results here, but you’ll really want to read up on the testing methodology — it’s great science hacking. Did you know about using saturated salt solutions to produce constant humidity levels for calibration? We didn’t.
The eBay hacker favorite, the so-called DHT22 module, doesn’t fare all that well, with one of six that [Robert] tested being basically horrible, and three of them breaking within two years of use. The one that works well, however, is pretty good. Feeling lucky?
The Bosch BME280 looks great. It costs a bit more as a bare part, and a few times more than that when it is mounted on a friendly module, but it seems to be very reliable. And you get a barometer thrown in for the extra work. Indeed, it performed so well that Hackaday contributor [Nava Whiteford] put the part under a scanning electron microscope to figure out what’s going on.
The other sensors were fine, with the HTU21D and SHT71 being standouts for their ultra-fast response. For the full details, go click on that link at the top. Having just installed a sextet of DHT22s in our house last year, we’re left with that sinking feeling that we may have gotten what we paid for, which wasn’t much. At least they’re all still running.
Thanks to [Dodutils] and [mac012345] via comments in another thread.
We’ve all been guilty of buying things we want, but don’t need. And that’s how [PodeCoet] found himself in possession of a couple of double-arc electric lighters, thanks to those far-eastern websites purveying cheap goods. ‘Tis the season of giving after all, justified [PodeCoet]. Being a hacker, the obvious thing to do was to make them belt out tinny tunes. If you’re still holding on to your gas lighters, don’t — because these electric ones are ‘oh so hackable’. Dual-arcs are the same, but twice the fun.
[PodeCoet] starts off with a tear down of the lighter, to figure out the schematic and understand how it works. There’s a charger IC for the LiPo, an unidentifiable micro-controller, a pair of FET’s driving a pair of power transistors, which in turn drive the HF output transformer at around 15.6kHz. He guesses that the “original micro-controller is probably an OTP part like a 12C508” but in the absence of a chipID he couldn’t be sure.
Instead of trying to break his head over it, he just swapped in a pin-compatible PIC12F1840. All that’s left to do is to write some quick-n-dirty code and sprinkle it with funny comments in order to modulate the output signal at audio frequencies. His first choice of tune was “We are Number One” by Lazy Town, the Icelandic educational musical comedy children’s television series (phew). But redditors are awesome, and someone asked him to add the “Imperial March” and [PodeCoet] obliged.
Since he was going to gift these lighters, the sneaky hacker added a prank in the code. Every time the button is pressed for more than two seconds, it works as normally expected and a counter is incremented. On the 20th count, and for one time only, the tune is played. No amount of pressing the button will play the tune again, confounding the user to wonder if he was hallucinating. This also helps ensure the lighter does not self-destruct prematurely, since the output transformer is likely designed for low duty cycles. His blog post contains all of the information needed to do this hack along with handy tips to avoid the problems he faced. A “Happy Birthday” tune would be great when lighting some birthday candles, we think.
[PodeCoet] has a fancy for high voltage stuff – check out “Home built Stun Baton turns you into a cop from Demolition Man“. This man surely loves his pranks, as evidenced by “Hacking your Co-Workers Label Makers“. And the farce is strong in this one — “Student trolls anti-Arduino Prof with parasite MCU“.
SKiDL is very, very cool. It’s a bit of Python code that outputs a circuit netlist for KiCAD.
Why is this cool? If you design a PCB in KiCAD, you go through three steps: draw the schematic, assign footprints to the symbolic parts, and then place them. The netlist ties all of these phases together: it’s a list of which parts are connected to which, the output of schematic capture and the input for layout. The ability to generate this programmatically should be useful.
For instance, you could write a filter circuit generator that would take the order, cutoff, and type of filter as inputs, and give you a spec’ed netlist as output. Bam! In your next design, when you need a different filter, you just change a couple of variables. Writing your circuits as code would make arranging the little sub-circuits modular and flexible, like functions in code.
At the very least, it’s an interesting alternative to the mouse, click, drag, click paradigm that currently dominates the schematic capture phase. Just as some of you like OpenSCAD for 3D modelling, some of you will like SKiDL for circuit design.
We’ve become so accustomed to the circuit diagram as the means of thinking about circuits that we’re not sure that we can ever give up the visual representation entirely. Maybe designing with SKiDL will be like sketching out block diagrams, where each block is a bit of Python code that generates a circuit module? Who knows? All we know is that it sounds potentially interesting, and that it’ll certainly be mind-expanding to give it a try.
Give it a shot and leave feedback down in the comments!
Finding a product that is everything you want isn’t always possible. Making your own that checks off all those boxes can be. [Peter Clough] took the latter route and built a small Bluetooth speaker with an LED visualization display that he calls Magic Box.
A beefy 20W, 4Ohm speaker was screwed to the lid of a wooden box converted to the purpose. [Clough] cut a clear plastic sheet to the dimensions of the box, notching it 2cm from the edge to glue what would become the sound reactive neopixel strip into place — made possible by an electret microphone amplifier. There ended up being plenty of room inside the speaker box to cram an Arduino Pro Mini 3.3V, the RN-52 Bluetooth receiver, and the rest of the components, with an aux cable running out the base of the speaker. As a neat touch, neodymium magnets hold the lid closed.