Author: Zoe Skyforest

3718 Articles

Automating Mobile Games With A Robot Arm

November 28, 2021 by 16 Comments

My Singing Monsters is one of those mobile titles that has users play simple games to earn coins and gems in the usual way. [Anykey] found that his son was a fan of the game, but that sometimes it felt a little rigged. Thus, rather than waste time playing themselves, he set up a robot to do the job for them. (Super-boring video, embedded below.)

The player must complete a basic but time-consuming memory game. Upon winning, the player gets to choose a prize from 17 mystery cards. The top prize of 1,000 diamonds always seemed to be hidden under another card, leading to the aforementioned frustration.

In order to test if the game was rigged, [Anykey] set up a uArm Swift Pro to play the game, with the robot arm moving a small stylus over the iPad playing the game. The iPad’s video was piped to a PC via HDMI out, going into a Camlink capture card. A Python script using OpenCV was then created to play the game automatically, and log the results of prizes gained along the way. All the code is up on GitHub.

After over 100 attempts, the robot never managed to pick the right card to score 1,000 diamonds. Given that there are only 17 cards to choose from, one would expect the 1,000 diamond prize to come up several times in that many selections.

It seems then that the prize selection for completing the memory game may not actually be down to picking the right card. Instead, the prize given is selected by some other calculation entirely.

We love a robot playing games at Hackaday, even if it’s as simple as Tic-Tac-Toe. Video after the break.

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The Trials And Tribulations Of SLA Printing A Portable Wii Handheld

November 28, 2021 by 9 Comments

The G-Boy kit revolutionized the subculture around building portable home consoles, allowing an entire Wii to be crammed into a form factor the size of a original Game Boy. [Chris Downing] is no stranger to the field, and sourced a G-Boy kit of his own to build it to the best of his abilities. (Video embedded after the break.)

However, he wanted to step up above the FDM-printed parts of the original kit. Thus, he contacted the kit developer Gman, who provided him with the 3D model files so he could attempt a higher-quality SLA print himself. [Downing] had some experience with SLA printing in the past with the Form 2, but found some unique challenges on this build with the Form 3.

The benefits of SLA printing are the finer detail and surface finish it delivers. This is particularly nice on things like enclosures and buttons which are handled regularly by the user. However, the standard resin that ships with the Form 3 had issues with warping, particularly on thin flat walls which make up the majority of the G-Boy case.

Other issues included the fact that the standard cured SLA resin is much harder to thread screws into than softer FDM plastic, something which frustrated assembly of the design. It’s also brittle, too, which leads to easy breakages.

As a fan of a properly finished product, [Downing] decided to sand and paint the enclosure regardless. Tragedy struck when the spray cans started to spit chunks due to being over a year old. However, it serendipitously turned into a win, producing an attractive granite stone-like finish which actually looks pretty good.

The G-Boy kit took Wii portable builds mainstream, and drew many new builders into the subculture. [Downing] may be a stalwart of the scene, but still learned new skills along the way of the build.

We can’t wait to see what happens next in the scene, though we’d suspect someone’s already out there chopping up a rare PlayStation 5 as we speak.

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This Raspberry Pi Mini ITX Board Has Tons Of IO

November 28, 2021 by 27 Comments

The Raspberry Pi now comes in a wide variety of versions. There are tiny little Zeros, and of course the mainstream-sized boards. Then, there’s the latest greatest Compute Module 4, ready to slot on to a carrier board to break out all its IO. The Seaberry is one such design, as demonstrated by [Jeff Geerling], giving the CM4 a Mini ITX formfactor and a ton of IO. (Video embedded after the break.)

The Seaberry sports a full-sized x16 PCI-E port, with only 1x bandwidth but capable of holding full-sized cards. There’s also four mini-PCI-E slots along the top, with four M.2 E-key slots hiding underneath. The board then has a M.2 slot in the middle for NVME drives, and x1 PCI-E slot hanging off the side.

Ports include a USB 2.0, a Cisco-style serial console port, two HDMI ports, and a Gigabit Ethernet jack. Two seperate 12V connectors are provided allowing for a redundant power supply setup, which can be made triple redundant with the addition of the right Power-over-Ethernet hardware. Naturally, the Seaberry also features the usual 40-pin GPIO header, the 14-pin CM4 IO header, as well as the usual DSI, CSI and RTC hookups.

The Mini ITX design is a particular boon. The Seaberry can easily be slapped into a mini PC case, and the power button and activity LEDs work just like you’d expect.

In testing the board, [Jeff Geerling] filled up almost every slot, trying to see how many cards will run on an Compute Module 4 with 8GB of RAM. Throwing in an NVME SSD drive, several Coral TPUs for machine learning, multiple network cards and a SATA interface caused no problems.

Not everything worked due to driver limitations, but everything enumerated on the bus just fine. [Jeff’s] earlier work paid dividends here. His previous attempts trying to get GPUs working on the platform meant opening up an extended BAR space for PCI devices wasn’t a problem.

Further attempts involved adding in a 12-card carrier loaded up with 7 more TPUs, 5 more WiFi cards, and 3 more NVME drives. Outside of some kernel panics from excess NVME drives, the Pi CM4 was still able to detect everything, showing it can address more than 20 PCI-E devices without major issues.

Throwing so many devices at the Pi CM4 may not have an obvious application in the mainstream, but it’s sure to prove useful to someone. We’re certainly enjoying watching [Jeff] push the limits of what’s possible with the CM4, and we hope he gets GPUs working soon.

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Magnus Effect Propels This Flettner Rotor Boat

November 27, 2021 by 13 Comments

The Magnus effect is a interesting and useful phenomena. [James Whomsley] from [Project Air] decided to put it to work on a small radio-controlled boat, successfully harnessing the effect. (Video, embedded after the break.)

The Magnus effect is an interesting thing, where fluid flowing over a rotating object generates an aerodynamic force at a right angle to the direction of the flow and the axis of rotation. (It’s why curveballs curve.) This can be used for propulsion on a boat, by spinning a tall cylinder called a Flettner rotor. This takes advantage of Magnus effect to generate thrust.

The boat uses a 3D-printed hull, sealed up with a leak sealer spray and lots of spray paint to avoid leaks.  In the center of the catamaran design, there’s a spinning rotor belt-driven by a brushless motor. Outside of the rotor for thrust, a simple rudder is used for steering.

With the rotor turning, the boat was able to successfully sail along with the benefit of the thrust generated from the wind. However, there were teething issues, with heavy winds quickly capsizing the boat. [James] realized that adding some proper keels would help avoid the boat tipping over.

We’ve seen [James] around these parts before, namely with the Magnus-effect aircraft that preceded this build.

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Mechanical Musical Sculpture Recalls The Four Muses

November 24, 2021 by 8 Comments

Music was created by humans, but often we find ourselves creating performances with machines. [Alana Balagot] and [Federico Tobon] did just that, constructing the stunning 4 Muses musical sculpture with their combined talents.

4 Muses is made up of four individual instruments, under the command of a single keyboard controller. The keyboard can be used to play the instruments live, or alternatively, can learn from the player or be used as a sequencer. It can also act as a simple device to play back music using the four instruments.

The pipe instrument uses servo-controlled valves, which allow air from a blower fan to reach several wood pipes. The xylophone instead uses solenoids to play its 13 tines. Percussion is provided by a mechanized cajón drum, using motors to actuate mallets that strike the various sections of the box. Meanwhile, hackers will be familiar with the concept of the motor-noise instrument, which drives stepper motors at different frequencies to generate tones.

Inside, a cavalcade of microcontrollers make everything work, from Arduino Megas and Teensys to NRF24s sending wireless packets from the controller to the instruments. [Alana] and [Federico] go in-depth with their documentation, highlighting the challenges they faced putting together the various instruments and showing how the final build came together.

Built with and brass hardware and sporting a variety of exquisite wood finishes, the final result is a quartet of machines that play beautiful music composed by [Alana] herself. Musical sculptures are often a great example of the artistry possible when putting electrons to work. Video after the break.

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Turkey fryer

Why Deep Frying Turkey Can Go Very Wrong

November 24, 2021 by 93 Comments

Tomorrow is Thanksgiving and that means Americans across the United States will be cooking up a turkey feast. One of the most popular ways to cook the bird is by deep frying it in oil.

Local TV stations everywhere spend this week warning about turkey frying. They’re not wrong… if things get out of hand you can end up burning down your house, if not your entire street. Let’s talk the science behind November turkey fires, and hopefully avoid a turkeyferno.

Simple Errors

The typical setup for deep frying a turkey involves lowering the bird into a big pot full of oil sitting on a gas burner. Ropes and pulleys are often used to lower the turkey into the pot to avoid getting one’s hands near the hot oil. Ideally, this should be done in a backyard, away from structures, to provide good ventilation and plenty of room in the case something does go wrong.

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Live Jam Kit Helps Electronic Musicians Stay In Sync

November 23, 2021 by 2 Comments

Jamming live with synths and drum machines can be fun, but for [Christian], there was a little something missing. He was looking for a way to keep everyone in the group on the beat and rocking out, and decided to build something to help.

The ethos of the build was to put one person ultimately in charge of the mix using Ableton. This stops the volume race, as each musician turns their own volume up and the jam devolves into a noisy mess. Each musician also gets a sync button they can hit if their instrument has drifted out of time. Everyone in the jam also gets their own monitor signal in their headphones, as well as a looper as well.

Individual players in the electronic jam can whip up a cool little loop, and spit it out to the main controller running Ableton using the looper. Then, they can mix up something else in their headphones without disrupting the main mix, before spitting it out as a loop again.

[Christian]’s demo video does a great job of showing how it all works. We particularly like the sync button, which gets rid of the usual frustrations when a sequencer in the jam trips over the tempo signal.

It’s all built with a Teensy, and seems like a great way to organize a jam with a bunch of different synths and drum machines. We’d certainly love to join in the fun.

We’ve seen other fun jam kits too, like this neat networked solution. Video after the break.

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