Analog Discovery 2 As A Vector Network Analyzer

June 20, 2018 by Al Williams 7 Comments

A while back, I posted a review of the Analog Discovery 2, which is one of those USB “do everything” instruments. You might recall I generally liked it, although I wasn’t crazy about the price and the fact that the BNC connectors were an extra item. However, in that same post, I mentioned I’d look at the device’s capabilities as a network analyzer (NA) sometime in the future. The future, as they say, is now.

What’s an NA?

In its simplest form, there’s not much to an NA. You sweep a frequency generator across some range of frequencies. You feed that into some component or network of components and then you measure the power you get out compared to the power you put in. Fancy instruments can do some other measurements, but that’s really the heart of it.

The output is usually in two parts. You see a scope-like graph that has the frequency as the X-axis and some sort of magnitude as the Y-axis. Often the magnitude will be the ratio of the output power to the input power as a decibel. In addition, another scope-like output will show the phase shift through the network (Y-axis) vs frequency (X-axis). The Discovery 2 has these outputs and you can add custom displays, too.

Why do you care? An NA can help you understand tuned circuits, antennas, or anything else that has a frequency response, even an active filter or the feedback network of an oscillator. Could you do the same measurements manually? Of course you could. But taking hundreds of measurements per octave would be tedious and error-prone.

Continue reading “Analog Discovery 2 As A Vector Network Analyzer” →

Friday Hack Chat: Ladyada On Creative And Interactive Robotics

June 20, 2018 by Brian Benchoff 7 Comments

Somewhere at the intersection of microcontrollers, open source toolchains, the Maker Movement, and the march of technology, there’s a fuzzy concept that can best be described as robotics or physical computing. Instead of a computer in a box or a dumb microcontroller, these projects interact with the outside world. Whether that’s through the Internet, tapping a bunch of sensors, or just waving the arm of a servo around, there’s a need for a platform that actually does all of this stuff. For this week’s Hack Chat, we’re going to be talking all about creative and interactive robots, and you’re invited.

Our guest for this week’s Hack Chat will be Limor “Ladyada” Fried, the founder of Adafruit, and someone who needs no introduction but we’re going to do it anyway. Adafruit began as a weird side project selling exact reproductions of the Roland TB-303, building cell phone jammers, and making guides to build your own USB power bank before USB power banks were a thing. This has grown into Adafruit, a company with over 100 employees in the heart of New York City, one of the best places for learning and making electronics, and a place that does everything Open Source with zero loans or VC money. By any objective measure, Adafruit has become the most successful business story to come out of the Maker Movement, however nebulously that can be defined.

This week the Hack Chat will be focused on the CRICKIT, the Creative Robotics and Interactive Construction Kit. The CRICKIT is an add-on to Adafruit’s Circuit Playground that allows you to build your own robot with CircuitPython, MakeCode, or just Arduino. There’s support for arts, crafts, sensors, audio, animatronics, physical computing, kinetic sculptures, science experiments, and just about anything else you can think of. Need an example? Here’s Blue Öyster Cult. Here’s that robot that came with the NES. It’s all great fun.

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the 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, June 22nd. Here’s a clock counting down the time until the Hack Chat starts.

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.

Print Physical Buttons For Your Touch Screen

June 20, 2018 by Brian McEvoy 5 Comments

Modern handheld gaming hardware is great. The units are ergonomic powerhouses, yet many of us do all our portable gaming on a painfully rectangular smartphone. Their primary method of interaction is the index finger or thumbs, not a D-pad and buttons. Shoulder triggers have only existed on a few phones. Bluetooth gaming pads are affordable but they are either bulky or you have to find another way to hold your phone. Detachable shoulder buttons are a perfect compromise since they can fit in a coin purse and they’re cheap because you can make your own.

[ASCAS] explains how his levers work to translate a physical lever press into a capacitive touch response. The basic premise is that the contact point is always touching the screen, but until you pull the lever, which is covered in aluminum tape, the screen won’t sense anything there. It’s pretty clever, and the whole kit can be built with consumables usually stocked in hardware stores and hacker basements and it should work on any capacitive touch screen.

Physical buttons and phones don’t have to be estranged and full-fledged keyswitches aren’t exempt. Or maybe many capacitive touch switches are your forte.

Continue reading “Print Physical Buttons For Your Touch Screen” →

Teardown: Box Of Pain (Gom Jabbar Sold Separately)

June 20, 2018 by Tom Nardi 34 Comments

I immediately felt uncomfortable when I realized this thing is called the “Breo iPalm520 Acupressure Hand Massager”. You’re supposed to stick your hand into it, and through unknown machinations it performs some kind of pressure massage complete with heating action. It’s like one of those pain boxes from Dune. It’s all the more disturbing when you realize the red button on the thing is an emergency release. That’s right, once your hand is in this contraption you can’t take it out until the thing has had its way with you or you tap out.

At least once a week I try to get to the local thrift store to look for interesting things. I’d like to be more specific than “interesting things”, but truth be told, I never really know what I’m looking for until I see it. Sure there’s the normal consumer electronics kind of stuff, but I’ve also found some very nice laboratory equipment, computer parts, software, technical books, etc. You just have to go regularly and keep an eye out for the occasional needle amongst the hay.

I want you to know, Dear Readers, that I did briefly summon the courage to put my hand into this thing and turn it on. Now I am not what one might call an overly brave man, and perhaps that might explain my personal experience. But when it started to hum and heat up, constricting around my hand to the point I couldn’t move my fingers, I screamed like a child and mashed the emergency button as if I was a pilot trying to eject from a mortally wounded aircraft. As far as Frank Herbert is concerned, I’m no human at all.

In an effort to better understand this torture device, lets open it up and see what lurks beneath that futuristic exterior.

Continue reading “Teardown: Box Of Pain (Gom Jabbar Sold Separately)” →

Bunnie Weighs In On Tariffs

June 20, 2018 by Adam Fabio 150 Comments

[Bunnie] has penned his thoughts on the new 25% tariffs coming to many goods shipped from China to the US. Living and working both in the US and China, [Bunnie] has a unique view of manufacturing and trade between the two countries. The creator of Novena and Chumby, he’s also written the definitive guide on Shenzen electronics.

All the marked items are included in the new tariffs

The new US tariffs come into effect on July 6th. We covered the issue last week, but Bunnie has gone in-depth and really illustrates how these taxes will have a terrible impact on the maker community. Components like LEDs, resistors, capacitors, and PCBs will be taxed at the new higher rate. On the flip side, Tariffs on many finished consumer goods such as cell phone will remain unchanged.

As [Bunnie] illustrates, this hurts small companies buying components. Startups buying subassemblies from China will be hit as well. Educators buying parts kits for their classes also face the tax hike. Who won’t be impacted? Companies building finished goods. If the last screw of your device is installed in China, there is no tax. If it is installed in the USA, then you’ll pay 25% more on your Bill of Materials (BOM). This incentivizes moving assembly offshore.

What will be the end result of all these changes? [Bunnie] takes a note from Brazil’s history with a look at a PC ISA network card. With DIP chips and all through-hole discrete components, it looks like a typical 80’s design. As it turns out the card was made in 1992. Brazil had similar protectionist tariffs on high-tech goods back in the 1980’s. As a result, they lagged behind the rest of the world in technology. [Bunnie] hopes these new tariffs don’t cause the same thing to happen to America.

[Thanks to [Robert] and [Christian] for sending this in]

Would You Look At That Yaw Control

June 20, 2018 by Brian Benchoff 38 Comments

[Jeff Bezos] might be getting all the credit for developing a rocket that can take off and land vertically, but [Joe Barnard] is doing it the hard way. He’s doing it with Estes motors you can pick up in any hobby shop. He’s doing it with a model of a Falcon 9, and he’s on his way to launching and landing a rocket using nothing but solid propellant.

The key to these launches is, of course, the flight controller, This is the Signal flight controller, and it has everything you would expect from a small board meant to mount in the frame of a model rocket. There’s a barometer, an IMU, a buzzer (important!), Bluetooth connectivity, and a microSD card slot for data logging. What makes this flight computer different is the addition of two connectors for standard hobby servos. With the addition of a 3D printed adapter, this flight controller adds thrust vectoring control. That means a rocket will go straight up without the use of fins.

We’ve seen [Joe]’s work before, and things have improved significantly in the last year and a half. The latest update from last weekend was a scale model (1/48) of the Falcon Heavy. In a 45-second video, [Joe]’s model of the Falcon Heavy launches on the two booster rockets, lights the center core, drops the two boosters and continues on until the parachutes unfurl. This would be impressive without active guidance of the motor, and [Joe] is adding servos and launch computers to the mix. It’s awesome, and certainly unable to be exported from the US.

A YouTube Subscriber Counter With A Tetris Twist

June 19, 2018 by Dan Maloney 1 Comment

When it comes to YouTube subscriber counters, there’s not much wiggle room for creativity. Sure, you can go with Nixies or even more exotic displays, but in the end a counter is just a bunch of numbers.

But [Brian Lough] found a way to jazz things up with this Tetris-playing YouTube sub counter. For those of you not familiar with [Brian]’s channel, it’s really worth a watch. He tends toward long live-stream videos where he works on one project for a marathon session, and there’s a lot to learn from peeking over his virtual shoulder. This project stems from an earlier video, posted after the break, which itself was a condensation of several sessions hacking with the RGB matrix that would form the display for this project. He’s become enamored of the cheap and readily-available 64×32 pixel RGB displays, and borrowing an idea from Mc Lighting author [toblum], he decided that digits being assembled from falling Tetris blocks would be a nice twist. [Brian] had to port the Tetris-ifying code to Arduino before getting the ESP8266 to do the work of getting the subs and updating the display. We think the display looks great, and the fact that the library is open and available means that you too can add Tetris animations to your projects.

None of this is to say that more traditional sub counters can’t be cool too. From a minimalist display to keeping track of all your social media, good designs are everywhere. And adding a solid copper play button is a nice touch too.

Continue reading “A YouTube Subscriber Counter With A Tetris Twist” →