Author: Al Williams

4471 Articles

Ooohhh, That Smell: Arduino Monitors Air Quality

April 23, 2021 by 26 Comments

According to [Dr. Tom Lehrer’s] song Pollution, “Wear a gas mask and a veil. Then you can breathe, long as you don’t inhale!” While the air quality in most of the world hasn’t gotten that bad, there is a lot of concern about long-term exposure to particulates in the air causing health problems. [Ashish Choudhary] married an Arduino with a display and a pollution sensor to give readings of the PM2.5 and PM10 levels in the air.

The sensor uses a laser diode and a photodiode to detect and count particles, while a fan moves air through the system. If you aren’t up on pollution metrics, PM2.5 is a count of very fine particles (under 2.5 microns) and PM10 is a count of particles for 10 microns. You can find a datasheet for the device online.

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Stepper Motor Analyzer Reveals All

April 23, 2021 by 15 Comments

In theory, you really don’t need much to work with electronics. A scope ought to do everything. However, for special purposes, it is handy to have meters, logic analyzers, and other special-purpose instruments. If you work on motion systems like 3D printers and CNC machines, you ought to have a way to look at stepper motors. You don’t? [Zapta] has a great Simple Stepper Motor Analyzer and [Teaching Tech] has a great video (see below) that shows some of the great things it can do.

What can it do? It analyzes the motor in place and can visualize what’s happening during stepping, microstepping, and other operating modes. Connecting the instrument is easy since you just use a four-pin pass-through connector.

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Visual Raspberry Pi With Node-Red And TensorFlow

April 22, 2021 by 13 Comments

If you prefer to draw boxes instead of writing code, you may have tried IBM’s Node-RED to create logic with drag-and-drop flows. A recent [TensorFlow] video shows an interview between [Jason Mayes] and [Paul Van Eck] about using TensorFlow.js with Node-RED to create machine learning applications for Raspberry Pi visually. You can see the video, below.

The video doesn’t go into much detail since it is only ten minutes long. But it does show how easy it is to do things like identify images using an existing TensorFlow model. There is a more detailed tutorial available, as well as a corresponding video, which you can see below.

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Make Your Own Variable Inductor

April 22, 2021 by 16 Comments

Inductors are not the most common component these days and variable ones seem even less common. However, with a ferrite rod and some 3D printing, [drjaynes] shows how to make your own variable inductor. You can see him show the device off in the video below.

The coil itself is just some wire, but the trick is moving the ferrite core in and out of the core. The first version used some very thick wire and produced an inductor that varied from 6 to 22 microhenrys. Switching to 22 gauge wire allowed more wire on the form. That pushed the value range to 2 to 12 millihenrys.

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Compute Like It Is 1975: 6th Edition Unix Reborn

April 21, 2021 by 13 Comments

If you crave experiencing or reliving what computing was like “back then” you have a lot of options. One option, of course, is to load an emulator and pretend like you have the hardware and software you are interested in. Another often expensive option is to actually buy the hardware on the used market. However, [mit-pdos] has a different approach: port the 6th edition of Unix to RISC-V and use a modern CPU to run an old favorite operating system.

It isn’t an exact copy, of course, but Xv6 was developed back in 2006 as a teaching operating system at MIT. You can find resources including links to the original Unix source code, commentary on the source code, and information about the original PDP 11/40 host computer on the project’s main page.

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Hacking An Air Assist For The Ortur Laser

April 21, 2021 by 13 Comments

Getting great results from a laser cutter takes a bit of effort to make sure all of the settings are just right. But even then, if the air between the material and the laser source is full of smoke and debris it will interfere with the laser beam and throw off the results. The solution is to add air assist which continuously clears that area.

Earlier this year I bought an Ortur laser engraver/cutter and have been hacking on it to improve the stock capabilities. last month I talked about putting a board under the machine and making the laser move up and down easily. But I still didn’t have an air assist. Since then I found a great way to add it that will work for many laser cutter setups.

I didn’t design any of these modifications, but I did alter them to fit my particular circumstances. You can find my very simple modifications to other designs on Thingiverse. You’ll also find links to the original designs and you’ll need them for extra parts and instructions, too. It is great to be able to start with work from talented people and build on each other’s ideas.

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AI Makes Linux Do What You Mean, Not What You Say

April 20, 2021 by 30 Comments

We are always envious of the Star Trek Enterprise computers. You can just sort of ask them a hazy question and they will — usually — figure out what you want. Even the automatic doors seemed to know the difference between someone walking into a turbolift versus someone being thrown into the door during a fight. [River] decided to try his new API keys for the private beta of an AI service to generate Linux commands based on a description. How does it work? Watch the video below and find out.

Some examples work fairly well. In response to “email the Rickroll video to Jeff Bezos,” the system produced a curl command and an e-mail to what we assume is the right place. “Find all files in the current directory bigger than 1 GB” works, too.

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