Robot Collects Ping Pong Balls For You

January 21, 2023 by Lewin Day 9 Comments

If you’ve ever played ping pong, table tennis, or beer pong, you know that it’s a struggle to hang on to the balls. [MaximeMonsieur] has designed a robot to handle picking them up so you don’t have to.

The robot is specifically designed to pick up ultra-light ping pong balls. To that end, it has a large spinning paddle that simply wafts the balls into its collector basket at the rear. The robot gets around with a simple two-motor drive system, relying on skid-steering with a castor wheel at the rear. An Arduino Uno runs the show, and navigates the robot around with the aid of ultrasonic sensors to avoid crashing into walls.

Overall, the robot shows the benefits of designing for a specific purpose. Such a design would likely be far less successful with other types of heavier balls, but for ping pong balls, the spinning paddle collector works great. We can imagine the robot being put to good use between sets to pick up all the lost balls around a table tennis court.

We’ve seen other ball collecting robots before, too.

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Beehive In A Bottle

January 21, 2023 by Bryan Cockfield 49 Comments

One of the most common types of beekeeping hive is based around the Langstroth hive, first patented in the United States in 1852. While it does have some nice features like movable frames, the march of history has progressed considerably while this core of beekeeping practices has changed very little. But that really just means that beekeeping as a hobby is rife with opportunities for innovation, and [Advoko] is pioneering his own modern style of beehive.

In nature, bees like to live inside of things like hollowed-out tree trunks, so he has modeled his hive design after that by basing it around large inverted plastic bottles. Bees can enter in the opening at the bottle and build their comb inside from the top down. The bottles can be closed and moved easily without contacting the bees, and he even creates honey supers out of smaller bottles which allows honey to be harvested without disturbing the core beehive.There are a number of strategies to improve the bees’ stay in the bottles as well, such as giving them wooden skewers in the bottle to build their comb on and closing the bottles in insulation to help the hives regulate their temperature more evenly and to keep them dark.

He hopes this idea will help inspire those with an interest in the hobby who wouldn’t otherwise have the large amount of money it takes to set up even a few Langstroth-type hives. Even if you don’t live in a part of the world where the Langstroth hive is common, this system still should be possible to get up and running with a minimum of financial investment. Once you’ve started, though, take a look at some other builds which augment the hive with some monitoring technology.

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RC Car Gets F1-Style DRS Rear Wing

January 21, 2023 by Lewin Day 1 Comment

DRS, or the Drag Reduction System, has become a key part of Formula 1 in the past decade. [Engineering After Hours] decided to implement the same system on an RC car instead.

The DRS system was implemented in Formula 1 to increase passing in the series. By moving a flap in the rear wing of the race cars, drag could be reduced, allowing a car to attain a higher top speed on the straights. The racing series limited the activation of the DRS wing to only cars following closely behind another. This artificially enabled them to gain a speed boost over the car in front to aid passing.

[Engineering After Hours] wanted to see if a tiny wing on a small RC car could work the same way. It would fundamentally come down to whether moving a tiny wing element would appreciably change the car’s drag or not. Naturally, on such a small scale, attaining high speeds would be necessary to detect much difference. At lower speeds, the difference in drag would likely be too negligible to notice.

The RC-scale DRS system fundamentally does work. With DRS engaged, flattening out the rear wing elements noticably reduced downforce at the rear. With the DRS not engaged, though, the rear wing on the car was creating so much downforce that the car was squatting at the rear and occasionally flipping end over end. [Engineering After Hours] didn’t get any top speed measurements, but estimated that the wing could potentially increase top speed by up to 7 mph with the DRS enabled.

We’ve seen [Engineering After Hours] bring other fun motorsport tech to RC cars before, too, like this amazing fan car build.

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3D Printed Triptych Shows Trio Of AI-Generated Images

January 20, 2023 by Tom Nardi 11 Comments

Fascinated by art generated by deep learning systems such as DALL-E and Stable Diffusion? Then perhaps a wall installation like this phenomenal e-paper Triptych created by [Zach Archer] is in your future.

The three interlocking frames were printed out of “Walnut Wood” HTPLA from ProtoPasta, and hold a pair of 5.79 inch red/black/white displays along with a single 7.3 inch red/yellow/black/white panel from Waveshare. There are e-paper panels out there with more colors available if you wanted to go that route, but judging by the striking images [Zach] has posted, the relatively limited color palettes available on these displays doesn’t seem to be a hindrance.

Note the clever S-shaped brackets holding in the displays.

To create the images themselves, [Zach] wrote a script that would generate endless customized portraits using Stable Diffusion v1.4, and then manually selected the best to get copied over to a 32 GB micro SD card. The side images were generated on the dreamstudio.ai website, and also dumped on the card.

Every 12 hours a TinyPico ESP32 development board in the frame picks some images from the card, applies the necessary dithering and color adjustments to make them look good on the e-paper, and then updates the displays. Continue reading “3D Printed Triptych Shows Trio Of AI-Generated Images” →

RP2040 DMA Hack Makes Another ‘CPU Core’

January 20, 2023 by Dave Rowntree 16 Comments

[Bruce Land] of Cornell University will be a familiar name to many Hackaday readers, searching the site for ‘ECE4760′ will bring up many interesting topics around embedded programming. Every year [Bruce] releases yet more of the students’ work out into the wild to our great delight. This RP2040-based project is a bit more abstract than some previous work and shows yet another implementation of an older hack to utilise the DMA hardware of the RP2040 as another CPU core. While the primary focus of the RP2040 DMA subsystem is moving data between memory spaces, with minimal CPU intervention, the DMA control blocks have some fairly complex behaviour. This allows for a Turing-complete CPU to be implemented purely with the DMA hardware and a sprinkling of memory.

The method ties up three of the twelve DMA channels, and is estimated to have a similar performance to ‘an Arduino’ but [Bruce] doesn’t specify which one of the varied models that could be. But who cares anyway? Programming the CPU is a matter of leveraging the behaviour of the hardware, which is all memory mapped and targetable by the DMA. For example, the CPU can waggle GPIO pins by using the DMA to write values to the peripheral address space. The basic flow can be seen in the image above. DMA0 is used as the program counter, which points DMA1 to an array of DMA control blocks, a sequence of which codes for some of the ‘opcodes’ of the CPU model. DMA0 chains to (hands over control to) DMA1 which reads the control blocks and configures itself accordingly. DMA1 performs whatever data move is programmed, chains to DMA2, which in turn reprograms the DMA0 program counter to point to the next block in the list to be executed by DMA1.

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A wooden table with walnut squares and a maple grid. The table has a large barrel-shaped curve on one end and the other is a representation of a wormhole with what look like two stretched cones connected through a narrow cylinder. The wooden grid looks stretch to follow the curvature of spacetime.

Wormhole Coffee Table Takes Woodworking To Another Dimension

January 20, 2023 by Navarre Bartz 20 Comments

While some people are happy with a simple coffee table to hold their snacks while watching Star Trek reruns, others want their furniture to go where no furniture has gone before. [Olivier Gomis] has definitely satisfied this need with his Wormhole Coffee Table. [YouTube]

The complicated shape and curvature of a (3D representation of a) wormhole isn’t easy to create, but [Gomis] managed to carve one without the aid of a CNC or 3D printer. Starting with walnut planks and maple veneer laminated together, he created a grid stackup to replicate the common representation of spacetime as a 2D grid. Using various arrangements of these grids, he built up the central section of the wormhole which looked like a low poly vase before he put it on the lathe for turning.

The lathe work on this build is simultaneously impressive and terrifying. Turning down the central portion of the wormhole required working between two large spinning squares of walnut, which [Gomis] admits was “scary.” Multiple custom jigs were required to keep parts flat and deal with the extreme curvature of the inside of the wormhole’s opening. If that weren’t enough, if you look down the wormhole, he has installed a set of LED lights that show the spacetime grid continuing on to parts unknown.

If you’d like to see another impressive wormhole, check out this Amazing STARGᐰTE With DHD And Infinity Mirror Wormhole.

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