Author: Al Williams

4504 Articles

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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Inside A DEC Hard Drive

April 19, 2021 by 40 Comments

A lot of technology from the not-so-distant past doesn’t resemble modern versions very much. For a case in point, look at the DEC RS08 disk drive meant to pair with a circa 1970 PDP-8. Paired with an RF08 controller, this was state of the art, holding 262K 12-bit words with a blistering access speed of almost 63K/second unless you were plugged into 50Hz AC when it was closer to 50K/second. [Uniservo] had the disk unit, but not the controller. Someone else had a controller, but no disk drive. So [Uniservo] is shipping the disk to its new owner in a move worthy of a Reeses’ Peanutbutter Cup. The problem? The disk is super fragile and shipping is risky, so he decided to remove the platter for separate packing. Good thing for us, because we get a peek inside.

The nickel-cobalt platter looks like a thick LP record with heads underneath. As you might guess from the data transfer specification, the motor was just a common AC motor that rotated the platter against the head.

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Power Supply Uses Thin Form Factor

April 19, 2021 by 8 Comments

We’ve seen lots of power supply projects that start with an ATX PC power supply. Why not? They are cheap and readily available. Generally, they perform well and have a good deal of possible output. [Maco2229’s] design, though, looks a lot different. First, it is in a handsome 3D-printed enclosure. But besides that, it uses a TFX power supply — the kind of supply made for very small PCs as you’d find in a point of sale terminal or a set-top box.

Like normal PC supplies, these are inexpensive and plentiful. Unlike a regular supply, though, they are long and skinny. A typical supply will be about 85x65x175mm, although the depth (175mm) will often be a little shorter. Compare this to a standard ATX supply at  150x86x140mm, although many are shorter in depth. Volume-wise, that’s nearly 967 cubic centimeters versus over 1,800. That allows the project to be more compact than a similar one based on ATX.

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