Tindie

Screenshot from video below: “Your Arduino Balancing Robot”

If you went to engineering school, which I’d guess at least some readers here have, you may have seen a problem or even implemented a real-world solution to control an inverted pendulum. Unlike a normal pendulum, where most of the mass is below the pivot point, inverted pendulums keep the mass vertical by applying a control scheme based on motion equations described here.

It’s the same principle that keeps Hoverboards and Segways vertical, and isn’t trivial to implement. On the other hand, with the correct components available, it shouldn’t be that hard. This is shown in the excellent writeup found here, and in the corresponding video below:

Though you can see how it can be built, there are quite a few components to be sourced, a body that needs to be cut out, and quite a bit of soldering to be done. Another simpler option is outlined in this article, and can be seen on display in the video below. Though easier to build, it features DC motors instead of the steppers used in the first example, making the control less precise.

Bots like these would be much simpler to implement with a proper PCB and all the parts available in one place. As far as I know, this style robot isn’t available on Tindie, as a kit or otherwise, presenting what seems like a great opportunity. For that matter, I’d find an inverted pendulum on a fixed axis pretty interesting, so that could be a simpler related build.

Keep Reading ›

Like many engineers, and I suppose accountants, or anyone that works with numbers on a regular basis, I am quite comfortable using a numeric keypad. On the other hand, if you need to use a non-decimal number system, like binary or hexadecimal for retro computing, it’s not nearly as convenient.

There are a few options, however, such as this binary keyboard, that’s designed to input characters only using two keys. Alternatively, on a normal keyboard, 1s and 0s are at least close together on the numpad, or you could simply park a finger over each digit, making binary input relatively easy. On the other hand, inputting hex values is a different story. Not only do you have to input 1 through 10, there’s also the pesky A though F characters, meaning you’ll have to stretch for the numbers on your keyboard or go back and forth between the numeric and “normal” keyboard. Not great.

So why not make something better yourself? If you’d like to create an “extended” numpad, Granz-Tronix has a solution with its Hex Keypad Kit. As shown, digits are arranged in a numeric order from the top down, though you could experiment with different key arrangements depending on how your computer or microcontroller interprets button presses. For that matter, there is no reason why something like this couldn’t be used to control other devices.

As shown in the first image, the current run of these devices has the last row of buttons hanging off of the board. Though fully functional, as of this writing they are available at a discounted price until this batch runs out.

Keep Reading ›

If you think electronic music first appeared sometime between the late 1970s and early 1980s, you likely wouldn’t be alone. However, one of the first, electronic instruments, the Thermin, was actually patented by its inventor, Léon Theremin, in 1928. This device uses two antennas to produce sound, one which controls the frequency, and another which controls the instrument’s volume.

In fact, you can see Theremin himself “banging out” a tune in the video below, in a playing method reminiscent of a violin.

These devices, though rare in actual musical performance, can be purchased from such companies as Moog, or you can put one together yourself from parts.

If you’d like a head start on putting together your own together, this package from MicroKits, seen demonstrated in the video below looks quite simple. With just a few jumpers, chips, and a small speaker placed on a breadboard, it can produce these weird sounds using two hand-controlled antennas!

For another kit option, check out my writeup on the Open Theremin, which, though a bit more expensive than this simple kit, would be more at home in a performance environment!

Keep Reading ›

Though it seems like a shame, Nixie tubes, which use a series of cathodes inside a low pressure gas filled tube to display numbers, are no longer produced or in common use. Though many of us don’t have a great idea of what these tubes look like in person, they can be seen to emit a nice warm glow in images, and have a 3D effect because of the cathode arrangement.

An actual Nixie tube. By Georg-Johann Lay CC BY-SA 3.0

Though interesting, these display devices have a number of disadvantages over LEDs and the like. These include the fact that they are (or were) comparatively difficult to manufacture, and the fact that they need an electrical potential of well over 100 volts to operate.

Because these devices are both rare, difficult to work with, yet oh-so-cool, hackers have come up with a few solutions that combine modern electronics with some of the more interesting features of this technology.

Examples of what people have come up with include an edge-lit tube seen on Hackaday in 2012; LIXIE, which uses the same sort of “light pipe” edge-lighting concept; and the Nixie Pipe, which again uses the same basic idea, but has functionality built-in that links several of these number displays together.

Naturally, multiple digits can be used to form one of the most popular modern uses for Nixie tubes, a clock! Now you can have a clock with the depth of a Nixie tube display without fooling with expensive vintage components that are quickly turning into unobtainium, or the complications of high-voltage electronics!

Keep Reading ›

For the past few months I’ve been working on a Strandbeest project (featured on Hackaday here) that I plan to get to walk under motor control. I also plan to have a head and tail assembly that can pan and tilt, as well as quite a bit of lighting. Though this isn’t my first foray into this type of contraption, I’ve never actually used a microcontroller to get these ‘beests to walk around, instead opting to use a heavily modified quadcopter for the brains of one, and “traditional” R/C equipment for the next.

This one though will be too complicated to easily control this way, and I’m thus opting to use an Arduino Mega as the brains of the device, along with an HC-06 Bluetooth module for communication. Interaction with the board has been surprisingly straightforward so far. You simply hook up the HC-06 to power and the appropriate Rx/Tx pins, then use an app to send it serial commands. I’ve had some success so far, and am excited about the control possibilities.

One thing that is a bit inconvenient is the fact that I need an Arduino with a separate board for the Bluetooth module. There is always the possibility of it getting disconnected, and if space was an issue, that would be quite inconvenient. Though it wouldn’t have been appropriate for my project, the BlueDuino Rev2 board solves this issue in a Nano-sized form factor. Now you don’t have to worry about hooking an extra chip up; BLE capabilities are already included. The board looks like a great solution for simple IoT and control challenges!

Bluetooth Control! [full video]

Keep Reading ›

PCB rulers — literally rulers made out of printed circuit boards — are an ingeniously nerdy idea. They are thick and stiff enough to make them useful as a straight edge, and the silk screen of the PCB is used to bring charts and tables to the party. You could design your own, or find them for sale on Tindie, Adafruit, the SV1AFN Design Lab, or many other places. We’ve even done a list of PCB rulers if you need more ideas.

Though they normally contain useful visual elements, for the most part these rulers are passive devices. For something a bit more interactive, may I present the Digirule. This device not only features length measurement in a binary format, but contains logic gates, flip flops, a counter, and 9 Easter egg modes as shown at 2:45 in the video below. Perhaps it won’t help you get more work done, but it looks like a really fun distraction, and the different logic functions could be a really useful learning tool!

Keep Reading ›

If you’re both interested in music/musical performance, and are reading Tindie’s blog, then the idea of combining lights or other electronics with this art form has probably crossed your mind on occasion. There are, of course, great examples of this already, such as this ESP8266-based saxophone lighting system, or the GRIDI music sequencer. Taking things in a much different, and not technically electronic direction is the Pyro-Trombone seen in the video below:

After supposedly learning how to play trombone in my one year of middle school band, it’s amazing to see instruments can actually sound really good when properly used. The flames are, of course, quite incredible as well!

As neat as these three examples are, they do have one thing in common, in that they are not trivial to set up (and potentially quite dangerous in at least one case). On the other hand, this Arduino Nano-based system includes everything you need to set up a percussion-controlled lighting system, with the exception of the lights themselves and a LiPo battery. The device works off of a piezoelectric sensor input, and can drive a 5 volt LED strip. As seen in the video below, it makes a very colorful, and apparently quite safe, display!

Keep Reading ›

If you’ve been following my writing for any time, you may have noted my general disdain for soldering. Perhaps it’s that I never really learned how to do it well, or the fact that when I worked in industry I took a lot of pride in my ability to design and build a very neat electrical cabinet using screw terminals as the connection points. The spring-loaded versions may be even better, but I never really used them much for whatever reason.

I suppose you could buy industrial connectors and use them on robotics projects, they tend to be too large to fit inside of many projects, and can be quite expensive as well. Here’s a link to some of these products from a very good, and relatively inexpensive industrial supplier, however they will likely still look expensive when compared to many hobby electronics components. Alternatively, you could resort to using heavy duty terminal blocks like these from eBay, but they’ll be overkill for most projects.

Screw Terminals by Simon A. Eugster via CC BY-SA 3.0

So what I would propose is something in the middle. Configurable screw terminals smaller and less expensive than those sold for industry, and able to accommodate hobbyist robotics and electronics projects. Tindie has a few screw terminal adapters, like this one for the Raspberry Pi (pictured at the top of the page), and this Arduino-compatible development board, but where are these wires supposed to go? Into a breadboard? Bah!!!

Perhaps this product exists and I just haven’t heard of it yet. Feel free ping me on Twitter @JeremySCook and let me know. Otherwise, I think it’s a great product opportunity!

Keep Reading ›

The fact that a Raspberry Pi can act as an actual computer may be obvious to most readers of this blog, but given the fact it is a circuit board with components on it, underestimating it isn’t the hardest mistake to make. If you’d like to make your ‘Pi look like it actually belongs in the living room as a media server, or even powering a desktop, here are a few options to consider:

Anodized Aluminum RPi3 Case

Showing off it’s internals here, this RPi3 case is made out of anodized Aluminum, which looks really great in its provided images. Beyond protecting the ‘Pi, the aluminum body acts as a passive heat sink, cooling the system down and improving performance.

Raspberry Case Classic

For a very different, if still beautiful take on things, this case is made from a single block of oak. Perhaps it could be used as a streaming device next to a turntable setup or in a similar “classy” environment. Cooling is provided by a generous grate on the top.

Pi Desktop

Image: element14

If you’d rather have something that looks all business, then the Pi Desktop, available from element14 on June 5th in North America, is worth a look. Besides a distinctly black finish, this device includes a power switch and an SSD interface.

Keep Reading ›

The Workless Lamp, according to its description on the Scalar Electronics’ website, “Shifts from cool to warm when it’s time to call it a day.” It’s also noted that this lamp is, “Only available as a gift,” and “Not on the Internet or configurable in any way. [It] Has one button, and the button does one thing.”

That’s kind of a nice change from everything being connected, and sometimes adjustable beyond usefulness. Behind this external simplicity though, lies some relatively complicated internals, including a PCB with a voltage regulator and a small microcontroller. This controls the custom lighting fixture to change between temperatures using a lighting fixture with an array of 2700 and 5000 Kelvin LEDs.

Packaging looks quite nice!

CJ Picklesimer, founder of the Scalar Electronics design firm, notes that he uses several Tindie products in this build. These include Toast-R-Reflow components from Gepetto Electronics, as well as an AVR ISP Pogo adapter from the same store, though he notes that he also could have used this model from Femtocow.

On that note, Picklesimer has his own Tindie store, which he says that while he doesn’t really make money off of that pursuit, enjoys “shipping my products to people if it makes them happy. He’s generously provided a discount code—”WORKLESS30″—that can be used for 30% off of anything there.

If you have a cool project you made using Tindie components or tools, feel free to ping me on Twitter or via Tindie’s official handle to have it featured! For that matter, Scalar Electronics is on Twitter as well if you have any lamp or electronics-related questions.

Keep Reading ›