Vroomba Gets Upgrades And A Spoiler

January 15, 2024 by 11 Comments

[Electrosync] is the creator and driver of the world’s fastest robotic vaccum cleaner, the Vroomba. It’s a heavily modified roomba capable of speeds of around 60 kph, well beyond the pedaling speed of most bicyclists. Despite being rejected by Guinness for a world record, we’re fairly confident that no other vacuum cleaners have gotten up to these speeds since the Vroomba first hit the streets. That’s not going to stop [electrosync] from trying to top his own record, though, and he’s brought the Vroomba some much needed upgrades.

The first, and perhaps most important, upgrades are to some of the structural components and wheels. The robot is much heavier than comparable RC vehicles and is under much greater strain than typical parts are meant to endure, so he’s 3D printed some parts of the chassis and some new wheels using a nylon-carbon fiber filament for improved strength. The wheels get a custom polyurethane coating similar to last time.

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Vulcan Nails First Flight, But Peregrine Falls Short

January 9, 2024 by 24 Comments

For those with an interest in the history of spaceflight, January 8th promised to be a pretty exciting day. Those who tuned into the early morning live stream were looking forward to seeing the first flight of the Vulcan Centaur, a completely new heavy-lift booster developed by United Launch Alliance. But as noteworthy as the inaugural mission of a rocket might be under normal circumstances, this one was particularly special as it was carrying Peregrine — set to be the first American spacecraft to set down on the lunar surface since the end of the Apollo program in 1972.

Experience has taught us that spaceflight is hard, and first attempts at it doubly so. The likelihood of both vehicles performing as expected and accomplishing all of their mission goals was fairly remote to begin with, but you’ve got to start somewhere. Even in the event of a complete failure, valuable data is collected and real-world experience is gained.

Now, more than 24 hours later, we’re starting to get that data back and finding out what did and didn’t work. There’s been some disappointment for sure, but when everything is said and done, the needle definitely moved in the right direction.

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No DAC? Try PDM

January 6, 2024 by 16 Comments

Ever notice that the ESP32-S3 doesn’t have a digital-to-analog converter? [Chris] did and asserts that he doesn’t care because he can just use the PDM system to get the same result. PDM — pulse density modulation — is similar to PWM and, like PWM, requires a filter that could range from a simple RC network to an active filter. You can see the result in the video below.

There are several ways [Chris] could produce the output he wanted. PWM was one choice, and some example code uses a timer to do PDM. However, that is not very efficient. The other alternative is to use the I2S output. However, this does require a few workarounds.

In particular, the I2S output is always stereo and incorporates a clock output that isn’t needed for this application. [Chris] simply output the same value on both channels and routed the clock to some pins that are normally used for startup options. That means they can’t easily be used for your own inputs, but it’s OK to use them for unimportant outputs.

We always enjoy seeing solutions like this because it can give you ideas for use in your own projects. Of course, this won’t apply to every project where you need a DAC, but it still might give you some ideas.

We have looked at PDM before. You could, too, build your own DAC hardware.

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Keeping Watch Over The Oceans With Data Buoys

December 28, 2023 by 12 Comments

When viewed from just the right position in space, you’d be hard-pressed to think that our home planet is anything but a water world. And in all the ways that count, you’d be right; there’s almost nothing that goes on on dry land that isn’t influenced by the oceans. No matter how far you are away from an ocean, what’s going on there really matters.

But how do we know what’s going on out there? The oceans are trackless voids, after all, and are deeply inhospitable to land mammals such as us. They also have a well-deserved reputation for eating anything that ventures into them at the wrong time and without the proper degree of seafarer’s luck, and they also tend to be places where the resources that run our modern technological society are in short supply.

Gathering data about the oceans is neither cheap nor easy, but it’s critically important to everything from predicting what the weather will be next week to understanding the big picture of what’s going on with the climate. And that requires a fleet of data buoys, outnumbering the largest of the world’s navies and operating around the clock, keeping track of wind, weather, and currents for us.

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Temperature Measurement By Wire

December 27, 2023 by 7 Comments

There’s an old joke about how to tell how tall a building is using a barometer. The funniest answer is to find the building owner and offer them a nice barometer in exchange for the information. We wonder if [DiodeGoneWild] has heard that one since his recent video details how to measure temperatures using an ohmmeter.

The idea is that wire changes its resistance based on temperature. So if you know the resistance of a lot of wire — maybe a coil — at room temperature and you can measure the resistance at temperature, it is entirely feasible to calculate the amount of temperature that would cause this rise in resistance.

Of course, there are many ways to measure resistance, too. It’s probably possible to measure parameters like operating current and estimate temperature for at least some circuits. The wire’s material also plays a part, and the online calculator lets you choose copper, aluminum, iron, or tungsten. You also need a lot of wire, a very accurate resistance measurement, or, preferably, both.

There are many ways to accurately measure resistance, of course. Then again, you can also get resistors specifically for the job.

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Game Graphics: Rasterization

December 26, 2023 by 4 Comments

Last time, I talked about racing the beam, a type of graphics used when memory was scarce. Now it’s time to step into the future with more memory and talk about what modern 2D games still do to this day: rasterization.

Just in time Memory

Continuing the trend set by racing the beam, rasterized graphics are also on a grid, just a much tinier one. Though not unique to rasterized, the “frame buffer” is the logical conclusion of bitmap mode fidelity: enough memory is allocated so that every pixel can have its own color. What’s different about a frame buffer is that everything is drawn before it is shown and, crucially, this doesn’t have to happen in the same order as the pixels are displayed. Rasterization draws entire shapes — triangles, lines and rectangles — into the frame buffer and the screen is typically updated all at once. Continue reading “Game Graphics: Rasterization” →

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Hackaday Links: December 24, 2023

December 24, 2023 by 10 Comments

Back near the beginning of the current Solar Cycle 25, we penned an article on what the whole deal is with solar cycles, and what could potentially lie in store for us as the eleven-year cycle of sunspot population developed. Although it doesn’t really come across in the article, we remember being somewhat pessimistic about things, thinking that Solar Cycle 25 would be somewhat of a bust in terms of increased solar activity, given that the new cycle was occurring along with other, longer-period cycles that tend to decrease solar output. Well, looks like we couldn’t have gotten that more wrong if we tried, since the Sun lashed out with a class X solar flare last week that really lit things up. The outburst came from a specific sunspot, number 3514, and clocked in at X2.8, the most powerful flare since just before the end of the previous solar cycle. To put that into perspective, X-class flares have a peak X-ray flux of 10-4 watts/m², which when you think about it is a lot of energy. The flare resulted in a strong radio blackout; pretty much everything below 30 MHz was unusable for a while.

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