Author: Lewin Day

3563 Articles

Microcontroller Load Meter Tells You How Hard It’s Currently Working

May 13, 2017 by 19 Comments

Writing code for embedded applications can be difficult. There are all sorts of problems you can run into – race conditions, conflicting peripherals, unexpected program flow – any of these can cause havoc with your project. One thing that can really mess things up is if your microcontroller is getting stuck on a routine – without the right debugging hardware and software, this can be a tricky one to spot. [Terry] developed a microcontroller load meter just for this purpose.

It’s a simple setup – a routine named loadmeter-task on the microcontroller sends a train of pulses to a mechanical ammeter. The ammeter is then adjusted with a trimpot to read “0” when the chip is unloaded. As other tasks steal CPU time, there’s less time for loadmeter-task to send its pulses, so the meter falls to the left.

Overall it’s a quick and easy bit of code you could add to any project with a spare GPIO pin, that might help you debug. Plus it’s cool to know how hard your project is pushing the silicon.

If you’d like to know more about what your chip is doing, check out this post about the usefulness of in-circuit debugging, or read about Bil Herd’s experiments with ICE and OBD-II.

HP Laptops Turn Up Keylogger Where You Wouldn’t Expect It

May 12, 2017 by 58 Comments

Keyloggers are nasty little things that have the potential to steal the credit card numbers of you and everyone you care about. Usernames and passwords can be easily stolen this way, so they’re a useful tool for the black hats out there. One would generally expect to find a keylogger in a dodgy movie torrent or perhaps a keygen for pirated software, but this week a keylogger was found in an audio driver for an HP laptop.

The logger was found by Swiss security researchers modzero. The Conexant HD Audio Driver Package version 1.0.0.46 and earlier apparently logs keystrokes in order to monitor things like the laptop’s volume up and down keys. The real killer here is that it feels the need to log all keystrokes detected to a readily accessible file, for reasons we can’t possibly fathom. It’s a huge security risk, but it doesn’t stop there – the driver also exposes the keystrokes through an API as well, creating an even wider attack surface for malicious actors. One can in principle access the keystroke log remotely.

There’s no word from the company yet, but we really want to know – why save the keystrokes to a file at all? Code left over from debugging, perhaps? Speculate in the comments.

They Have Electronics In Junk Mail Now

May 11, 2017 by 50 Comments

On the way to the mailbox, you might be expecting bills, birthday cards, perhaps a grocery store catalogue or two. [Steve] was like you, once – until an embedded computer showed up in the junk mail.

The mailer turned out to be from the Arconic corporation – some sort of publication trying to sway a board of directors vote one way or the other. But far more interesting is the hardware inside. The device consisted of a 3″ LCD screen within folded cardboard, some buttons and a micro USB port. After the device let the smoke out when [Steve] attempted to charge it, the next step was naturally to perform a full teardown.

It was a simple job to identify the chips inside which still had their factory markings, and [Steve] found that it appeared to share its design with an Audi marketing material from 2014. It’s rather amazing that such technology is cheap enough for this sort of mass mailout, though [Steve] notes that it’s rather an imprudent move to post out a “fire hazard that needs to be specially recycled”.

This reminds us of the e-paper Esquire magazine display from a few years back.

Build Your Own Hydroponic Wheel

May 10, 2017 by 21 Comments

Hydroponics is an effective way of growing plants indoors through the use of water medium and artificial lighting. It often involves having a system to raise and lower the water level around the plants to let the roots breathe, however this can require some non-trivial plumbing. [Peter] wanted to instead explore the realm of wheel hydroponics to grow some ingredients for salad.

The idea is to have pods mounted on a rotating assembly, similar to the carriages on a Ferris Wheel. By rotating the wheel slowly, each pod spends a certain amount of time submerged, and a certain amount of time in free air. This allows the water level to remain constant and only the pods need to move.

The tank for the build is a simple plastic storage bin from a local hardware store, with the wheel assembled from various odds and ends and laser cut components, making this a build very possible for those with access to a hackerspace. A stepper motor provides the motive power, with the assembly completing approximately one rotation per hour.

[Peter] has run the device for several months now, noting that there are issues with certain plants maintaining their hold to the wheel, as well as algae growth in the water medium. There’s room for development but overall, it’s a great build and we hope [Peter] will be serving up some delicious fresh salads soon.

For another take, perhaps you’d like your hydroponics solar powered?

[Thanks Nils!]

Measuring Walking Speed Wirelessly

May 10, 2017 by 9 Comments

There are a lot of ways to try to mathematically quantify how healthy a person is. Things like resting pulse rate, blood pressure, and blood oxygenation are all quite simple to measure and can be used to predict various clinical outcomes. However, one you may not have considered is gait velocity, or the speed at which a person walks. It turns out gait velocity is a viable way to predict the onset of a wide variety of conditions, such as congestive heart failure or chronic obtrusive pulmonary disease. It turns out, as people become sick, elderly or infirm, they tend to walk slower – just like the little riflemen in your favourite RTS when their healthbar’s way in the red. But how does one measure this? MIT’s CSAIL has stepped up, with a way to measure walking speed completely wirelessly.

You can read the paper here (PDF). The WiGate device sends out a low-power radio signal, and then measures the reflections to determine a person’s location over time. Alone, however, this is not enough – it’s important to measure the walking speed specifically, to avoid false positives being triggered by a person simply not moving while watching television, for example. Algorithms are used to separate walking activity from the data set, allowing the device to sit in the background, recording walking speed data with no user interaction required whatsoever.

This form of passive monitoring could have great applications in nursing homes, where staff often have a huge number of patients to monitor. It would allow the collection of clinically relevant data without the need for any human intervention; the device could simply alert staff when a patient’s walking pattern is indicative of a bigger problem.

We see some great health research here at Hackaday – like this open source ECG. Video after the break.

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LED Tail Lights For Improved Motorcycle Visibility

May 10, 2017 by 32 Comments

Motorcycles are hard to see at the best of times, so riders are often concerned with making themselves as visible as possible at all times. [Josh] wanted to do this by creating a custom tail light for his Ducati 749.

The tail light is based around SMD LEDs, mounted in acrylic to diffuse the light. The construction is beautiful, using custom PCBs and carefully machined acrylic to match the lines of the bike.

As far as warning lights go, a brighter light will be more obvious in the day time, but could actually hinder visibility at night by blinding other road users. To this end, [Josh] built the tail light around an ATtiny 45, which could be programmed with various routines to optimise the light level depending on ambient conditions. Another feature is that the light’s brightness pulses at high frequency in an attempt to attract the eye. Many automakers have experimented with similar systems. The ATtiny controls the lights through a PCA9952 LED controller over I2C. This chip has plenty of channels for controlling a bunch of LEDs at once, making the job easy.

Overall, it’s a very tidy build that lends a very futuristic edge to the bike. We’ve seen [Josh]’s work in this space before, too – with this awesome instrument display on a Suzuki GSX-R.

Butter Passing Battlebot

May 6, 2017 by 14 Comments

The idea of purpose is one of great importance to many sentient beings; one can only imagine the philosophical terror experienced by a robot designed solely to pass butter. Perhaps wishing to create a robot with more reason to exist, [Micah “Chewy” Leibowitz] decided to build this battlebot armed with a flamethrower, named Flamewar.

In the video, we see it rather successfully facing off against a robot named T800, at least in the early part of the fight. T800 is armed with a spinning weapon, and while it is able to deliver a heavy thump thanks to stored kinetic energy, more often than not T800 seems to knock itself over rather than do any serious damage to Flamewar. Flamewar is repeatedly able to fire its primary weapon, as the flamethrower is built into its arms, far above the reach of T800’s armament. We won’t spoil the ending of the fight. Video below the break.

The robot was built by [Micah] who competes with [Team Tiki], who have documented some of their past builds online. We would like to see some footage of Flamewar actually passing some butter, though. The bout was a part of Robogames 2017, and we’re impressed that such things like flamethrowers are allowed in the rules. Obviously safety is a paramount concern of these events, so it’s awesome to see they’ve found a way to make things work.

If you’re unaware of the dairy product reference, fill yourself in here. We’ve seen other takes on this, too.

We love seeing combat robots here at Hackaday. If you’re thinking about getting started yourself, why not get started with an ant-weight bot to cut your teeth?

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