Particle Sniffer For Pollution Point Sources

April 2, 2020 by 13 Comments

When measuring air quality, particulate matter is an important metric to watch. The PM2.5 rating refers to particulate matter that has a diameter of less than 2.5 micrometers. While it’s often measured by authorities on a city-wide basis, [rabbitcreek] wanted a way to track down point sources indoors.

The tool [rabbitcreek] built is in a similar form factor to a typical infrared workshop thermometer. Inside, it packs a Honeywell HPMA115S0-TIR laser particle sensor, hooked up to an ESP32 which runs the show. The sensor chosen makes things easy, with the device already set up with a blower and inlet and outlet ports for taking accurate readings.. Results are displayed on an SSD1306 OLED screen. It’s all wrapped up in a 3D printed case with a trigger grip, and a dog nose on the front which hints at the devices true purpose.

In testing, the device proves capable of detecting point sources of atmospheric particulates like flowers and a toaster. It’s something we’re sure would prove handy to those working in HVAC and environmental assessment industries. We’ve seen other rigs for monitoring particulates before, too. Video after the break.

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Using The Steam Controller With LEGO Motors

April 1, 2020 by 1 Comment

While Valve’s Steam Controller was ultimately a commercial failure, there’s no denying it’s an interesting piece of hardware. With dual trackpads, a wealth of buttons, and Bluetooth capability, it could be the ideal way to control your next build. Thanks to a recent project by [geggo], now you’ve even got an example you can follow.

A custom PCB holding an ESP32 and DRV8833 dual H-bridge motor controller is used to interface with standard LEGO motors using their stock block-like connectors. That means the board is a drop-in upgrade for whatever motorized creation you’ve already built.

Since the ESP32 obviously has WiFi in addition to Bluetooth, that also means this little board could be used to control LEGO projects over the local network or even Internet with some changes to the firmware.

Interestingly, while Valve officially enabled Bluetooth on the Steam Controller back in 2018, it sounds like some undocumented poking and reverse engineering was necessary to get it working here. That’s great for those of us who like a good hack, but if you’re more interested in just getting things working, [geggo] has been good enough to release the source code to get you started.

If you’re not interested in Bluetooth but want to get your creation up and moving, we’ve recently covered how one hacker used the ESP8266 to bring his LEGO train to life by integrating it into his smart home.

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Teaching Robots Workplace Etiquette

April 1, 2020 by 3 Comments

Most often, humans and robots do not have to work directly together, instead working on different parts in a production pipeline or with the robot performing tasks instead of a human. In such cases any human-robot interaction (HRI) will be superficial. Yet what if humans and robots have to work alongside each other? This is a question which a group of students at MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) have recently studied some answers to.

In their paper on human-robot collaborative tasks (PDF), they cover the three possible models one can use for this kind of interaction: there can be no communication (‘silent’), the communication can be pre-programmed (state machine), or in this case a Markov model-based system. This framework which they demonstrate is called CommPlan and it uses observation data from human subjects to construct a Markov model that can integrate sensor data in order to decide on its next action.

In the experiment they performed (the preparation of a meal; see the embedded video after the break), human subjects had to work alongside a robot. Between the three different approaches, the CommPlan one was the fastest, using voice interaction only when it deemed it to be necessary. The experiment’s subjects expressed hereby a preference for bidirectional communication, much as would occur between human workers.

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Making PCBs With A Vinyl Cutter

April 1, 2020 by 26 Comments

You might assume that you need a lot of expensive stuff to make your own PCBs, but that isn’t the case: you can do it with a vinyl cutter and a few common chemicals and tools. [Emiliano Valencia] has laid out the entire process. While we’ve seen plenty of make your own PCB guides before, this one goes a bit further as it covers using the vinyl cutter to make solder masks, so you can use it for surface mount designs.

The end result of the process that [Emilano] lays out is the tinyDice, a cute little electronic die that can fit on a keyring. The whole process is very well written up, and even experienced PCB makers will probably find a few useful tricks here.

The really interesting part for us was using the vinyl cutter to make three parts of the process: the etching mask, the solder mask that protects the traces and the solder stencil that applies the solder to the pads for surface mounting. Continue reading “Making PCBs With A Vinyl Cutter” →

A Digital Pitch Pipe Gets You In Tune

April 1, 2020 by 4 Comments

Some humans are blessed with perfect pitch, an ability that comes in handy when pursuing the musical arts. For many others though, a little help is often appreciated. A pitch pipe is a handy way to find the starting note of a performance, and [Isaac] decided to build his own in the digital realm.

The project is based on the Adafruit Circuit Playground express, which packs in all the peripherals needed right on board. The buttons are used to select the pitch required, with the LEDs used to display the selected note. Blue means flat, green means natural, and red means sharp. A 3D printed outer ring is clipped on to the board to denote the pitches for the user. To play the note, the user simply blows on the pitch pipe. The onboard MEMS microphone detects this and plays the note on the onboard speaker.

It’s a tidy little project that is a great way to get one’s feet wet with embedded programming and working with audio. We’ve seen the Circuit Express pop up before too, such as in this pizza-box DJ mixer. Video after the break.
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Impractical Switches For The Bored Maker

April 1, 2020 by 14 Comments

Cabin fever: the inability to socialize with other humans does weird things to the human brain. Then again some of us are born to stand out, and one such amazing maker, [Lee], is spending time making weird switches from basically anything.

So what would you consider weird? How about using a piece of pasta? How about using the conductivity of an empty sink? There is even an experiment with breakfast cereal, though we do not recommend it for production use. [Lee] continues to pour experiments into Twitter and recently has gotten some conductive tape. Stick some on a game joystick and you got yourself an instant switch on a switch.

These experiments prove that there is a lot you can do with the stuff you have around your house and the other end of the circuit doesn’t necessarily need to be a humble LED. You could get more interesting results with adding the likes of a microcontroller like an ATtiny. Coupling it with a DIY LED badge would be a great idea and we’d love to see what you come up with.

Stay Smarter Than Your Smart Speaker

April 1, 2020 by 56 Comments

Smart speakers have always posed a risk to privacy and security — that’s just the price we pay for getting instant answers to life’s urgent and not-so-urgent questions the moment they arise. But it seems that many owners of the 76 million or so smart speakers on the active install list have yet to wake up to the reality that this particular trick of technology requires a microphone that’s always listening. Always. Listening.

With so much of the world’s workforce now working from home due to the global SARS-CoV-2 pandemic, smart speakers have suddenly become a big risk for business, too — especially those where confidential conversations are as common and crucial as coffee.

Imagine the legions of lawyers out there, suddenly thrust from behind their solid-wood doors and forced to set up ramshackle sub rosa sanctuaries in their homes to discuss private matters with their equally out-of-sorts clients. How many of them don’t realize that their smart speaker bristles with invisible thorns, and is even vulnerable to threats outside the house? Given the recent study showing that smart speakers can and do activate accidentally up to 19 times per day, the prevalence of the consumer-constructed surveillance state looms like a huge crisis of confidentiality.

So what are the best practices of confidential work in earshot of these audio-triggered gadgets?

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