Choosing A ‘Scope: Examining Bandwidth

October 5, 2016 by Jenny List 72 Comments

A few weeks ago I asked the Hackaday community for some help and advice in buying a new budget oscilloscope. Thank you very much to those of you who responded both here online and in person among my friends closer to home. I followed the overwhelming trend in the advice I received, and bought myself a Rigol DS1054z, an instrument with which I am very happy. It’s a nominally a 50 MHz scope, but there’s a software hack that can bring it up to 100 MHz. How fast can it go?

My trusty Cossor, its 2 MHz bandwidth as yet unverified.

This question became a mini scope-shootout after a conversation with my Hackaday colleague [Elliot] about measuring oscilloscope bandwidth, and then my fellow Oxford Hackspace members producing more than one scope for comparison. You know who you are, thank you. I found myself with ready access to several roughly equivalent models and one very high-end one in specification terms representing different strata of test equipment manufacture, and with the means to examine their performance.

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Taking A U2F Hardware Key From Design To Production

September 29, 2016 by Bryan Cockfield 17 Comments

Building a circuit from prototyping to printed circuit board assembly is within the reach of pretty much anyone with the will to get the job done. If that turns out to be something that everyone else wants, though, the job gets suddenly much more complex. This is what happened to [Conor], who started with an idea to create two-factor authentication tokens and ended up manufacturing an selling them on Amazon. He documented his trials and tribulations along the way, it’s both an interesting and perhaps cautionary tale.

[Conor]’s tokens themselves are interesting in their simplicity: they use an Atmel ATECC508A specifically designed for P-256 signatures and keys, a the cheapest USB-enabled microcontroller he could find: a Silicon Labs EFM8UB1. His original idea was to solder all of the tokens over the course of one night, which is of course overly optimistic. Instead, he had the tokens fabricated and assembled before being shipped to him for programming.

Normally the programming step would be straightforward, but using identical pieces of software for every token would compromise their security. He wrote a script based on the Atmel chip and creates a unique attestation certificate for each one. He was able to cut a significant amount of time off of the programming step by using the computed values with a programming jig he built to flash three units concurrently. This follows the same testing and programming path that [Bob Baddeley] advocated for in his Tools of the Trade series.

From there [Conor] just needed to get set up with Amazon. This was a process worthy of its own novel, with Amazon requiring an interesting amount of paperwork from [Conor] before he was able to proceed. Then there was an issue of an import tariff, but all-in-all everything seems to have gone pretty smoothly.

Creating a product from scratch like this can be an involved process. In this case it sounds like [Conor] extracted value from having gone through the entire process himself. But he also talks about a best-case-scenario margin of about 43%. That’s a tough bottom line but a good lesson anyone looking at building low-cost electronics.

Hackaday Prize Entry: Raspberry Pi Thermal Imaging

September 25, 2016 by Jenny List 12 Comments

High up on the list of desirable technologies that are edging into the realm of the affordable for the experimenter is the thermal camera. Once the exclusive preserve of those with huge budgets, over the last few years we’ve seen the emergence of cameras that are more affordable, and most recently a selection of thermal camera modules that are definitely within the experimenter’s range. They may not yet have high resolution, but they are a huge improvement on nothing, and they are starting to appear in projects featured on sites like this one.

One such device is the Melexis MLX90621, a 16×4 pixel thermal sensor array in a TO39 can with an I2C interface. It’s hardly an impulse purchase in single quantities and nor is it necessarily the cheapest module available, but its price is low enough for [Alpha Charlie] to experiment with interfacing it to a Raspberry Pi for adding a thermal camera overlay to the pictures from its visible light camera.

The wiring for the module is simplicity itself, and he’s created a couple of pieces of software for it that are available on his GitHub repository. mlxd is a driver daemon for the module, and mixview.py is a Python graphical overlay script that places the thermal array output over the camera output. A run-through of the device and its results can be seen in the video below the break.

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Smart Watch Hack Lets You Use Your 3.5mm Headphones With An IPhone 7

September 23, 2016 by James Hobson 54 Comments

As you may have heard, the iPhone 7 is ditching the 3.5 mm headphone jack in the name of progress and courage. Whatever your take on that, it leaves the end user out in the cold if — for instance — their preferred headphones still use the old format. Here to save you from an untimely upgrade is YouTuber [Kedar Nimbalkar], who has modified a Bluetooth Smartwatch to incorporate a 3.5 mm jack to allow continued use your current headphones.

After opening up the smartwatch [Nimbalkar] removes the speaker, solders in a 3.5 mm headphone jack and clips out an opening in the watch’s case that maintains the watch’s sleek exterior.

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How To Drill A Curved Hole

September 22, 2016 by James Hobson 34 Comments

Next time you’re renovating and need to run some cables around corners in you walls, save yourself some frustration by building [izzy swan]’s corner drilling rig. It’s something akin to a custom tunnel boring machine but on a small scale.

Starting with a piece of steel, [izzy] traced and cut out a 90 degree curve with an attached arm that will allow it to rotate from a central block. He then grabs a random drill bit and attaches it to a flex shaft which is secured to the leading point of the steel curve. To complete the handy setup the entire rig is bolted to a block that will clamp over the corner stock.

As it stands, it takes some elbow grease to get the drill through, but it’s not a purpose built setup. On a second demonstration, the flex shaft breaks, but the idea is there. Now, [izzy] advises that this is most easily accomplished when re-framing walls with no drywall obstructing your drill, but the concept for this rig could nonetheless prove handy for welding, grinding, and so forth along any angled curve.

If instead you want to push your carpentry skills to their limits, build a wooden Vespa.

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Arcade Button Pressing Game

September 20, 2016 by Jenny List 17 Comments

When every month brings out a fresh console blockbuster game that breaks new boundaries of cinematic immersion in its gameplay, it’s easy to forget that sometimes the simplest of game interfaces can be rewarding.

“Hele Norges Knapp” (“All of Norway’s Button”), is a good example. As you might expect, it’s a button, a large arcade-style one, and the gameplay is simple. Press the button as many times as you can in 30 seconds. It’s a project from Norwegian Creations, and it was produced as a promotion that toured the country for one of Norway’s debit card payment systems.

The blog post and video is frustratingly light on hardware or software details, and their is nothing about it in their GitHub presence. But they tell us that at its heart is a Teensy 3.2 with an audio board, driving the big 7-segment displays for the scoreboard and the WS2801 LED lighting.

The button itself is Adafruit’s 100mm Massive Arcade Button, and given that it was pressed over a million times by eager Norwegians it would seem this project has proved its robustness.

The video below the break has details of construction and of the game in action, and there is another far more corporate promotional video on Facebook featuring a host of Bright Young People honing their button action in a sun-kissed Norway that looks almost tropical. The game itself does look as though it could be an amusing diversion in the same vein as those fairground strength tests.

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Hackaday Prize Entry: Mouse Controlled Microscope

September 19, 2016 by Jenny List 9 Comments

You might imagine that all one should need to operate a microscope would be a good set of eyes. Unfortunately if you are an amputee that may not be the case. Veterinary lab work for example requires control of focus, as well as the ability to move the sample in both X and Y directions, and these are not tasks that can easily be performed simultaneously with only a single hand.

[ksk]’s solution to this problem is to use geared stepper motors and an Arduino Mega to allow the manual functions of the microscope to be controlled from a computer mouse or trackball. The motors are mounted on the microscope controls with a custom 3D-printed housing. A rotary selector on the control box containing the Arduino allows the user to select a slow or fast mode for fine or coarse adjustment.

It’s fair to say that this project is still a work in progress, we’re featuring it in our series of posts looking at Hackaday Prize entries. However judging by the progress reported so far it’s clear that this is a project with significant potential, and we can see the finished product could be of use to anyone operating the microscope.

We’ve featured one or two mouse controlled projects over the years, though not controlling microscopes. Here’s one mouse controlled robot arm, and we’ve covered another arm with a 3D mouse.