An Easy Camera Slider Build

May 8, 2019 by 1 Comment

As smartphone cameras improve with each new generation, making quality video content is getting easier all the time. This means it takes a little more to stand out, so it pays to get creative with your cinematography. A slider is a great way to get some different shots, and you can build one pretty cheaply too (Youtube link, embedded below).

For smooth motion, [Nikodem Bartnik] used aluminium extrusion for the rails, along with some roller bearing wheels designed to suit. The wheels are built into a 3D printed carriage, which is also fitted with a spherical clamping camera mount. It’s all wrapped up with some socket head cap screws and 3D printed brackets to tie it all together.

Dimensional accuracy is key to the smooth operation of a slider, so you’ll want to have your printer set up well if you’re going to attempt this one. [Nikodem] demonstrates the slider is capable of taking the weight of an mid-range SLR with a tastefully sized lens, but if you’re going for something telephoto, you might want to go for something bigger. You could also consider a motorized rig instead. Video after the break.

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Pushing 3D Printed Wheels And Transmissions To The Limit

May 8, 2019 by 19 Comments

What do you do if you want a robot with great mobility? Walking is hard, and wheels are good enough, especially if you use the ‘wheels within wheels’ Mecanum setup. But you need torque, too. That’s what makes this entry into the Hackaday Prize so fantastic. It’s a Mecanum wheel of sorts, with an integrated gear set that produces a phenomenal amount of torque using a small, cheap stepper motor.

The wheel itself if 3D printed and fully parametric, using nylon weed wacker filament for the treads. This allows the wheel to scoot back and forth like a Mecanum wheel, or at the very least like one of those hyper mobile wheeled robots you see from time to time. It goes backwards, forwards, and side to side, and also has a zero turn radius.

A 3D printed Mecanum wheel is great, but how on earth do you drive it? That problem is solved with this hybrid planetary/strain-wave  3D-printed gear set. [Daren] has created a very compact ‘single’ stage gear set that fits right on top of a stepper motor. It’s thin, flat, and has a gear reduction of about 66:1. That’s a lot of torque in a very small package. Both of these projects are combined, and together they represent a freaky wheel with a lot of torque.

Even though [Daren] doesn’t have a robot in mind for this build, these are most certainly the building blocks of a fantastic robot, and a great entry in the Hackaday Prize.

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Fun With Negative Resistance: Jellybean Transistors

May 8, 2019 by 10 Comments

The concept of negative resistance has always fascinated me. Of course, a true negative resistance is not possible, and what is meant is a negative differential resistance (NDR). But of course knowing the correct term doesn’t do anything to demystify the topic. Negative resistance sounds like an unusual effect, but it turns out to be relatively common, showing up in places like neon lamps and a number of semiconductor structures. Now’s as good a time as any to dig in and learn more about this common principle.

NDR means a portion of a device’s I/V curve where the current falls with increasing applied voltage. The best-known semiconductor device exhibiting negative resistance is the tunnel diode, also known as the Esaki diode after one of the Nobel-Prize-winning discoverers of the quantum tunneling effect responsible for its operation. These diodes can perform at tremendous speeds; the fastest oscilloscope designs relied on them for many years. As the transistor and other technologies improved, however, these diodes were sidelined for many applications, and new-production models aren’t widely available — a sad state for would-be NDR hackers. But, all hope is not lost.

Rummaging through some old notebooks, I rediscovered an NDR design I came up with in 2002 using two common NPN transistors and a handful of resistors; many readers will already have the components necessary to experiment with similar circuits. In this article, we’ll have a look at what you can do with junkbox-class parts, and in a future article we’ll explore the topic with some real tunnel diodes.

So, let’s see what you can do with a couple of jellybean transistors!

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A Datasheet Manifesto For The 21st Century

May 8, 2019 by 25 Comments

Selecting electronic components can be a frustrating process, one of trawling through the websites of distributors such as DigiKey, Mouser, or RS, and then poring over manufacturer data sheets. These documents produced as detailed guides to the technical specifications of a device contain enough to give an engineer everything they need to incorporate it into their designs.

Unfortunately many datasheets fall short of the ideal, and have instead become marketing documents designed to “win the socket”. This is a problem that vexes Boldport’s [Saar Drimer], and he has written a personal manifesto outlining his vision to make the world of datasheets a better place.

It’s a common-sense designer’s wishlist, and it’s one we could completely get behind. Chief among his desires are web-readable datasheets as well as the ubiquitous PDFs, with full data in human and machine readable forms instead of tiny printed graphs and tables. He also makes a plea for better UX testing to combat the scourge of the inaccurate pad layout, to which we’d add providing footprints ready-made for all popular CAD packages. These and the rest of his manifesto would be a game-changer, and wouldn’t displace the existing paper or PDF sheet for those who still use them. Whether or not the manufacturers will take heed is anyone’s guess, but to have such an ideal laid out is a start.

If you’re not familiar with [Saar]’s work, you’re in for a treat. Boldport produce some of the most beautiful artistic PCBs, and we’ve featured them before more than once.

Thanks to our colleague [Ted Yapo] for the header image.

This Atomic Pi Eats Other Pis For Lunch

May 8, 2019 by 102 Comments

The world is full of single board computers that want a slice of the Raspberry Pi action. Most of them are terrible. But fools and their money, yadda yadda, and there’s a new sucker born every minute. The latest contender to the Raspberry Pi is the Atomic Pi. It’s an x86-based single board computer that costs $35, shipped to your door. Is it worth it? Is it even in the same market as a Raspberry Pi? Or is it just a small budget computer without a box? I have no idea.

With that said, the Atomic Pi comes with an Intel Atom x5-Z8350 with Intel HD Graphics (Cherry Trail). There is 2 GB of DDR3L-16000, 16 GB of eMMC, and an SD slot for storage. Connectivity is a full HDMI port (primary audio out), USB 3.0 and 2.0 ports, a Mediatec RT5572 used for WiFi, a Qualcomm CSR8510 for Bluetooth 4.0, a “Legitimate licensed BIOS”, and a real-time clock. Overall, you’re looking at a top-of-the-line tablet computer from four years ago. One that would run Windows.

To use all the features of the Atomic Pi, you will need to buy a $15 breakout board to supply power to the board, and use a large industrial power supply, the kind you would normally find bolted to a RepRap or a homemade CNC machine. You will need to supply both 5 V and 12 V to the board if you would like to use the Class D audio amplifier, but if you only want to use audio over HDMI, supplying only 5 V will do. If you want to boot this board, it looks like you’ll need to bring a USB/TTL cable to make everything work. This may be a tough sell to a crowd with zero experience booting a bare Linux system. That said, it runs Nintendo 64 emulators well, which is the only reason people buy Raspberry Pis anyway.

Is the Atomic Pi the single board computer you need? I don’t know. But we’ve got an Atomic Pi on order, and we’re ready to go with a full review when it show up.

Arduino’s Pluggable Discovery Programs With Any Protocol

May 8, 2019 by 9 Comments

The first Arduino was serial, and over the decade and a half, this has been the default way to upload code to an Arduino board. In 2008, support for in-circuit programmers was added, and later port detection was added. The latest version of the Arduino IDE adds something new: pluggable discovery. Now any protocol is supported by the Arduino IDE.

This feature is the brainchild of [Paul Stoffregen], creator of the Teensy. If you’ve ever used a Teensy, you’ll remember the Teensyduino application used to upload code to the board. The Teensy uses HID protocol instead of serial for uploading. After working to improve the integration between the Teensy and Arduino IDE, [Paul] stated extending the DiscoveryManager. After some discussion with the Arduino developers, this feature was then added to Arduino 1.8.9, released a month or so ago.

There are some issues with Pluggable Discovery, most importantly that it doesn’t yet exist in the Arduino Command Line Interface (yeah, that exists too). If you’re looking to contribute to Open Source, that would be a nice project to pick up.

With the right JSON, and configuration, it is now theoretically possible to extend the Arduino IDE to any sort of protocol. This means (again, theoretically), it’s possible to update the firmware in your DIY MIDI synth over SysEx message, or a parallel port, maybe. Someone is going to upload to an Arduino board over PCIe, eventually.