Hacking The ZH03B Laser Particle Sensor

October 9, 2018 by Tom Nardi 23 Comments

Laser particle detectors are a high-tech way for quantifying whats floating around in the air. With a fan, a laser, and a sensitive photodetector, they can measure smoke and other particulates in real-time. Surprisingly, they are also fairly cheap, going for less than $20 USD on some import sites. They just need a bit of encouragement to do our bidding.

[Dave Thompson] picked up a ZH03B recently and wanted to get it working with his favorite sensor platform, Mycodo. With a sprinkling of hardware and software, he was able to get these cheap laser particle sensors working on his Raspberry Pi, and his work was ultimately incorporated upstream into Mycodo. Truly living the open source dream.

The ZH03B has PWM and UART output modes, but [Dave] focused his attention on UART. With the addition of a CP2102 USB-UART adapter, he was able to connect it to his Pi and Mac, but still needed to figure out what it was saying. He eventually came up with some Python code that lets you use the sensor both as part of a larger network or service like Mycodo and as a stand-alone device.

His basic Python script (currently only tested on Linux and OS X), loops continuously and gives a running output of the PM1, PM2.5, and PM10 measurements. These correspond to particles with a diameter of 1, 2.5, and 10 micrometers respectively. If you want to plug the sensor into another service, the Python library is a bit more mature and lets you do things like turn off the ZH03B’s fan to save power.

These sensors are getting cheap enough that you can build distributed networks of them, a big breakthrough for crowd-sourced environmental monitoring; especially with hackers writing open source code to support them.

A Better Charger For Your Coin Cell Batteries

October 9, 2018 by Brian Benchoff 12 Comments

Rechargeable coin cell batteries are great for all your small projects. They look exactly like regular coin-cell batteries, but in a shocking turn of events you can recharge these little guys. They can put out a reasonable amount of current, and they’re small. Just what you need for your Arduino smart watch, or whatever else the kids are doing these days.

But if these batteries are rechargeable, you need a charger. That’s where [Jon]’s entry for the Hackaday Prize comes in handy. It’s a small, cheap charger for LIR2032 and other rechargeable batteries comes in. It’s barely larger than the battery itself, and it plugs right into a USB port. How this isn’t a product already, we’ll never know.

The circuit on this coin cell charger is built from an MCP73831, a nice single cell, lithium ion and lithium polymer charge management controller. In the standard, ‘I only need to read the first page of the datasheet’ configuration, this chip can put 500 mA into a battery. Standard rechargeable coin cells only have a capacity of 40 mAh, so you’ve got plenty of headroom at 1C.

The total cost for this project was under $8 for three boards, and a BOM cost of $2 for one. That’s fourteen bucks for three of them, if you know how to solder, compared to a standard, off-the-shelf charger for about $20. Building this is cheaper than buying the equivalent product. It’s unbelievable, but true.

A Funny Thing Happened On Ada Lovelace Day…

October 9, 2018 by Elliot Williams 43 Comments

Today is Ada Lovelace Day, a day to celebrate and encourage women in the fields of science and technology. The day is named after “Augusta Ada King-Noel, Countess of Lovelace, born Byron”, or Lady Ada Lovelace for short. You can read up more on her life and contribution to computer science at Wikipedia, for instance.

But it’s not really fair to half of the world’s population to dedicate just one day to observing the contributions of female scientists and then lavish all the laurels solely on Lovelace. So last year, the day after Ada Lovelace day, Brian Benchoff sent an internal e-mail at Hackaday HQ suggesting we tell the stories of other women in science. We put our heads together and came up with a couple dozen leads so quickly, it was clear that we were on to something good.

From a writer’s perspective, the stories of women in science are particularly appealing because they are undertold. Sure, everyone knows of Marie Curie’s brilliant and tragic dedication to uncovering the mysteries of radioactivity. But did you know how Rita Levi-Montalcini had to hide from the Italian Fascists and the German Nazis using fake names, doing research on scarce chicken eggs in her parent’s kitchen, before she would eventually discover nerve growth factor and win the Nobel Prize? We didn’t.

Do you know which biochemist is the American who’s logged the most time in space? Dr. Peggy Whitson, the space ninja. But the honor of being the first civilian in space goes to Soviet skydiver Valentina Tereshkova. Margaret Hamilton was lead software engineer on the code that got the first feet on the moon, but in the days before astronauts had learned to trust the silicon, John Glenn wanted Katherine Johnson to double-check the orbital calculations before he set foot in the Friendship 7.

And on it goes. Maria Goeppert-Mayer figured out the structure of nuclear shells, Kathleen Booth invented assembly language, and Françoise Barré-Sinoussi discovered HIV. Stephanie Kwolek even saved Hackaday writer Dan Maloney’s life by inventing Kevlar.

In all, we’ve written 30 profiles of women in science in the last year — far too many to list here by name. You can browse them all by using the Biography category. (We’ve thrown in biographies of a few men too, because women don’t have a monopoly on neat stories.)

We’re not done yet, either. So thank you, Ada Lovelace, for giving us the impetus to cover the fascinating stories and important contributions of so many women in science!

Dirty Video Mixing With The Raspberry Pi Zero

October 9, 2018 by Tom Nardi 32 Comments

Don’t get too excited now, we aren’t talking about that kind of dirty video. There’s plenty of other places on the Internet you can go to find that sort of thing. No, this video mixer is “dirty” because it combines two composite video streams into one garbled up mess that’s best viewed on an old CRT TV. Why, you may ask? Because rock and roll, that’s why.

Created by [Luke Blackford] as a visual for his band’s performances, the “Dirty Pi” is an exceptionally simple way to create some wild imagery with two Raspberry Pi Zeros. It might not be the most practical of devices, but if you want so throw some creepy looking video up on screens all over the house (say for an upcoming Halloween party), this is a fantastic way to do it on the cheap.

The idea is simple: connect the oft-forgotten composite video outputs of two Pi Zeros to a potentiometer, which then leads to the display. Play different videos on the Pis with the media player of your choice, and twiddle the potentiometer to create ghosting and interference. If you want to get that true 1980’s retro feel, put the whole thing into an old VHS cassette like [Luke] did, and you’re ready to rock.

Those who’ve been around the block a few times might recognize this trick as a variation of the [Karl Klomp] Dirty Video Mixer, and [Luke] tells us he likes this project because he was able to pull it off without writing any code or even doing any complex wiring, though he does imagine a future version where he adds some remote control functionality.

If you like your video mixers with more smarts and less dirt, we’ve covered a very slick build using the LM1881 in the past.

Continue reading “Dirty Video Mixing With The Raspberry Pi Zero” →

Google Discovers Google+ Servers Are Still Running

October 9, 2018 by Tom Nardi 70 Comments

Google is pulling the plug on their social network, Google+. Users still have the better part of a year to say their goodbyes, but if the fledgling social network was a ghost town before, news of its imminent shutdown isn’t likely to liven the place up. A quick check of the site as of this writing reveals many users are already posting their farewell messages, and while there’s some rallying behind petitions to keep the lights on, the majority realize that once Google has fallen out of love with a project there’s little chance of a reprieve.

To say that this is a surprise would be disingenuous. We’d wager a lot of you already thought it was gone, honestly. It’s no secret that Google’s attempt at a “Facebook Killer” was anything but, and while there was a group of dedicated users to be sure, it never attained anywhere near the success of its competition.

According to a blog post from Google, the network’s anemic user base isn’t the only reason they’ve decided to wind down the service. A previously undisclosed security vulnerability also hastened its demise, a revelation which will particularly sting those who joined for the privacy-first design Google touted. While this fairly transparent postmortem allows us to answer what ended Google’s grand experiment in social networking, there’s still one questions left unanswered. Where are the soon to be orphaned Google+ users supposed to go?

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Flying Human Head Lands Just In Time For Halloween

October 9, 2018 by Tom Nardi 15 Comments

We love the fall here at Hackaday. The nights are cooler, the leaves are changing, and our tip line starts lighting up with some of the craziest things we’ve ever seen. Something about terrifying children of all ages just really speaks to the hacker mindset. That sounds bad, but we’re sure there’s a positive message in there someplace if you care to look hard enough.

Today’s abomination is a truly horrifying human head quadcopter, which exists for literally no other reason than to freak people out. We love it. Created by [Josh] and a few friends, the “HeadOCopter” is built around a meticulously detailed 3D print of his own head. This thing is so purpose-built that they didn’t even put landing gear on it: there’s no point sitting on the ground when you’re in the business of terrorizing people from above.

Sure, you could do this project with a cheap plastic skull. But there’s no way it would have the same effect. [Josh] created this monstrosity by scanning his own head with the Microsoft Kinect, cleaning the model up in ZBrush, adding in mounts for hardware, and 3D printing the result. After doing some smoothing and filling, the head got passed off to artist [Lisa Svingos] for the final painting. He even thought to include an FPV camera where one of his eyes should be, giving a whole new meaning to the term.

As for the quadcopter hardware itself, it uses a BrainFPV RADIX flight controller (get it?) and 12×5 props on Sunnysky V3508 motors with 30A BLHELI ESCs. Measuring 1 meter (3.2 feet) from motor to motor, it’s an impressive piece of hardware itself; head or no head.

This project reminds us of the flying ghost we saw years back, but we have to admit, this raises the bar pretty high. We’re almost afraid to see what comes next.

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Is 2018 Finally The Year Of Windows On The Robot?

October 9, 2018 by Steven Dufresne 52 Comments

Microsoft is bringing ROS to Window 10. ROS stands for Robot Operating System, a software framework and large collection of libraries for developing robots which we recently wrote an introductory article about, It’s long been primarily supported under Linux and Mac OS X, and even then, best under Ubuntu. My own efforts to get it working under the Raspbian distribution on the Raspberry Pi led me to instead download a Pi Ubuntu image. So having it running with the support of Microsoft on Windows will add some welcome variety.

TurtleBot 3 at ROSCon 2018, Photo: Evan Ackerman/IEEE Spectrum

To announce it to the world, they had a small booth at the recent ROSCon 2018 in Madrid. There they showed a Robotis TurtleBot 3 robot running the Melodic Morenia release of ROS under Windows 10 IoT Enterprise on an Intel Coffee Lake NUC and with a ROS node incorporating hardware-accelerated Windows Machine Learning.

Why are they doing this? It may be to help promote their own machine learning products to roboticists and manufacturing. From their recent blog entry they say:

We’re looking forward to bringing the intelligent edge to robotics by bringing advanced features like hardware-accelerated Windows Machine Learning, computer vision, Azure Cognitive Services, Azure IoT cloud services, and other Microsoft technologies to home, education, commercial, and industrial robots.

Initially, they’ll support ROS1, the version most people will have used, but also have plans for ROS2. Developers will use Microsoft’s Visual Studio toolset. Thus far it’s an experimental release but you can give it a try by starting with the details here.

[Main Image Credit: Microsoft]