IoT Pool Monitor Helps You Keep It Crystal Clear

April 16, 2022 by Lewin Day 5 Comments

Having a pool is great, but it also requires significant monitoring and maintenance to keep it crystal clear and clean. The OPNpool controller from [Coert Vonk] aims to help in this task, integrating neatly into the smart home ecosystem of today.

OPNpool runs on an ESP32, and is capable of monitoring pool controllers, pumps, and chlorinators, as well as working with thermostats and other hardware to control the state of the pool. This allows the system to do useful things like run high-powered pumps when electricity is cheapest, or to find the best timing to run heating circuits. The controller relies on MQTT messaging and can integrate with Home Assistant for those that prefer to run their own cloud-independent smart home systems.

With WiFi onboard the ESP32, there’s no need for a hardwired LAN connection, and the system can be administered remotely over the web. It’s also capable of talking with other hardware over RS-485 and bringing it under its own control. With OPNpool installed, monitoring pool conditions can be done from the leisure of one’s deck chair with a smartphone, rather than squinting and dark LCDs in equipment cabinets.

It’s a useful tool that could be just the ticket for the savvy, IoT-aware pool owner. We’ve seen other DIY pool controllers before, too. With summer just around the corner, it’s the perfect time to get hacking!

Easy, Extensible, Open

April 16, 2022 by Elliot Williams 16 Comments

I’m a huge DIY’er. I don’t like to buy things when I can build them myself. But honestly, that doesn’t always end up in the optimal allocation of my time, when viewed from a getting-stuff-done perspective. Sometimes, if you’ve got a bigger project in mind, the right way is the quick way, and the quick way is buying something that already works. But when that something is itself not hackable, you’d better be darn sure that it does what you need, and what you could reasonably expect to need in the future, out of the box. And that’s where extensibility comes in.

It’s rare to find products out there that are designed to be both easy to use for the newbie, but extensible for the advanced user. For one, it’s hard work to tick either one of these boxes alone, so it’s twice as hard to nail both. But my other sinking suspicion is that designers tend to have an end user in mind, and maybe only one end user, and that’s the problem. When designing for the newbie, convenience is king. Or if targeting the pro, you maximize flexibility, but perhaps at the expense of designed-in complexity.

There’s a way out, a cheat code, if you will. And that’s making the project open source. Go ahead and hide the complexity from the new user if you want — as long as the pro is able to dive into the schematics or the source code, she’ll figure out how to extend it herself. Openness frees the designers up to worry about making it easy to use, without compromising its flexibility.

I think that this blend of easy and extensible, through openness, is what fundamentally drove the success of Arduino. On the surface layer, there are libraries that just do what you want and drop-down menus with examples to access them. But when you needed to actually use the chip’s hardware peripherals directly, there was nothing stopping you. For the community at large, the fact that all of the code was openly available meant that extending the base was easy — and let’s not beat around the bush, the community’s libraries, tutorials, and example projects are the real reason for the success of the platform.

Look around you, and look out when you’re making that next non-DIY shortcut purchase. Is it easy to use? Can you make it do the things that it doesn’t yet do? Just two simple requirements, yet they seem to knock out so many products if you want both. Then look at those that are both simple and flexible — are they also open? At least in my little world, the answer is almost always “yes”.

Tiny Pneumatic Tool Made From A Single(-ish) Bolt

April 16, 2022 by Dan Maloney 17 Comments

We’ve noticed a couple of things about the “Widget from a Single Bolt” genre of metalworking videos. The first thing is that almost all of them need to use a freakishly large bolt, and many of them also rely on other materials to complete the build. And secondly, these builds all pretty much depend on a lathe to transform the bolt into the intended widget.

While this single-bolt pneumatic graving tool build is guilty on that first count, it somehow manages to avoid needing a lathe. Not that [AMbros Custom] wouldn’t have greatly benefited from a lathe to make this somewhat specialized and unusual tool a reality. A graving tool or graver is used during metal engraving, the art of making controlled cuts into flat metal surfaces to render complicated designs. A powered graver like this can make engraving faster and more precise than a traditional manual graver, which is typically powered by light taps with a special hammer.

The lathe-less build [AMbros] undertook was quite ambitious given the number of moving parts and the tight tolerances needed for a pneumatic tool. The real hero here is the hand drill pressed into service as an impromptu lathe; teamed with various tools from files to emery cloth to even a Dremel and an angle grinder, it did a respectable job turning down the various parts. The entire build is shown in the video below, and it’s worth a watch just to see what ingenuity can accomplish when coupled with sheer persistence.

Hats off to [AMbros] for sticking with what was admittedly a problematic build, and here’s hoping a lathe is in his future. With that, he may be able to pull off other impressive “single-bolt” builds, like this combination padlock. Or throw another bolt or two in and pull off this cryptex-like safe.

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Paper Tape Reader Self-calibrates, Speaks USB

April 16, 2022 by Donald Papp 20 Comments

Input devices consisting of optical readers for punched paper tape have been around since the earliest days of computing, so why stop now? [Jürgen]’s Paper Tape Reader project connects to any modern computer over USB, acting like a serial communications device. Thanks to the device’s automatic calibration, it works with a variety of paper materials. As for reading speed, it’s pretty much only limited to how fast one can pull tape through without damaging it.

Stacked 1.6 mm PCBs act as an enclosure, of sorts.

While [Jürgen]’s device uses LEDs and phototransistors to detect the presence or absence of punched holes, it doesn’t rely on hardware calibration. Instead, the device takes analog readings of each phototransistor, and uses software-adjusted thresholds to differentiate ones from zeros. This allows it to easily deal with a wide variety of tape types and colors, even working with translucent materials. Reading 500 characters per second isn’t a problem if the device has had a chance to calibrate.

Interested in making your own? The build section of the project has all the design files; it uses only through-hole components, and since the device is constructed from a stack of 1.6 mm thick PCBs, there’s no separate enclosure needed.

Paper tape and readers have a certain charm to them. Cyphercon 4.0 badges featured tape readers, and we’ve even seen the unusual approach of encoding an I²C byte stream directly onto tape.

Calculating Pi On The 4004 CPU, Intel’s First Microprocessor

April 15, 2022 by Lewin Day 26 Comments

These days we are blessed with multicore 64-bit monster CPUs that can calculate an entire moon mission’s worth of instructions in the blink of an eye. Once upon a time, though, the state of the art was much less capable; Intel’s first microprocessor, the 4004, was built on a humble 4-bit architecture with limited instructions. [Mark] decided calculating pi on this platform would be a good challenge.

It’s not the easiest thing to do; a 4-bit processor can’t easily store long numbers, and the 4004 doesn’t have any native floating point capability either. AND and XOR aren’t available, either, and there’s only 10,240 bits of RAM to play with. These limitations guided [Mark’s] choice of algorithm for calculating the only truly round number. Continue reading “Calculating Pi On The 4004 CPU, Intel’s First Microprocessor” →

Javascript Is Everywhere. Even MSDOS

April 15, 2022 by Al Williams 34 Comments

Although pundits have joked that Java’s “write once, run everywhere” slogan might be better expressed as “write once, debug everywhere,” a relative of Java — JavaScript — has delivered on both promises better than its namesake. Thanks to its proliferation in browsers, JavaScript is a veritable lingua franca of computer languages which has led to entire applications being written in it using tools like Node.js and Electron, and not just browsers. But what if you are still using MSDOS or Windows 98? We know some of you do, at least on retro machines. Don’t feel left out, the DOjS project has jSH, a JavaScript engine for DOS and related operating systems.

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2022 Sci-Fi Contest: A Friendly Wall Drawing Robot

April 15, 2022 by Lewin Day 8 Comments

Drawing on walls is fine for children, but adults tend to get bored quickly with such antics. Even more so when they realize who is responsible for cleaning up afterwards. Instead, consider delegating those duties to a friendly helper by the name of Fumik, as [engineer2you] has done.

Fumik, who looks like a cute little jellyfish, can draw pictures up to 5 meters wide and 3 meters high, making for a massive canvas. Powered by an Arduino Mega 2560 outfitted with a CNC shield, a pair of stepper motors drive pulleys with toothed belts to move Fumik to various positions along the wall. Another smaller stepper motor is used to drive the pen forwards and backwards as needed. Fumik can be programmed to trace out various designs in SVG format. These must be converted to code and programmed into the Arduino, at which point Fumik can begin work, drawing on the wall with its pen.

It’s a fun build, and based on photos shared by [engineer2you,] Fumik is quite able at drawing clean and neat designs without a lot of smudging or jagged lines. As a bonus, it’s easy to swap out the pen, so multicolored designs can be drawn in multiple passes.

We’ve seen other robot drawing builds before, too, like this capable portrait artist. Video after the break.

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