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Archive for the ‘Raspberry Pi’ Category

With events of all sizes on hold and live sports mostly up in the air, it’s a great time to think of new ways to entertain ourselves within our local circles. Bonus points if the activity involves running around outside, and/or secretly doubles as a team-building exercise, like [KarelBousson]’s modernized version of Capture the Flag.

Much like the original, the point of this game is to capture the case and keep it for as long as possible before the other team steals it away. Here, the approach is much more scientific: the box knows exactly who has it and for how long, and the teams get points based on the time the case spends in any player’s possession.

Each player carries an RFID tag to distinguish them from each other. Inside the case is an Arduino Mega with a LoRa shield and a GPS unit. Whenever the game is afoot, the case communicates its position to an external Raspi running the game server.

If you haven’t met LoRa yet, check out this seven-part introductory tutorial.

Taking a paper list to the grocery store seems like a good idea, at least until you get there and try to use it. Did you remember to bring a pen? Great. How about a clipboard so you don’t punch through the paper when crossing something off? Apps are easier to use for this, especially the ones with checkboxes, but you’ll still have to enter everything manually. Wouldn’t it be easier (and way more fun) to just scan the barcodes of stuff you need into a list before you chuck the packaging?

That’s exactly the idea behind [DavidE281]’s barcode scanner, which is designed to work with the Bring! app. All he has to do is scan a barcode, and the product ends up in a tidy list on his phone. It’s a simple build that’s based around the M5StickC, which is an ESP32 dev kit that has a small display and a 6-axis IMU along with some other goodies. [David] combined it with a 2D barcode scanner that has a serial port and designed a printed case that joins them together.

Here’s how it works: the M5Stick sends the barcode over MQTT to an external Raspberry Pi that’s running Home Assistant. The Pi does a lookup in a spreadsheet and sends the data to the Bring! app over a community-built API. At the same time, it sends the product name back to the M5Stick’s display to confirm that it was added to the list. Check out bite-sized demo video after the break.

Scanning barcodes is super fun. So why not use an IoT barcode scanner to keep track of everything you own?

[Harrison] has been busy finding the sweeter side of quarantine by building a voice-controlled, face-tracking M&M launcher. Not only does this carefully-designed candy launcher have control over the angle, direction, and velocity of its ammunition, it also locates and locks on to targets by itself.

Here comes the science: [Harrison] tricked Alexa into thinking the Raspberry Pi inside the machine is a smart TV named [Chocolate]. He just tells an Echo to increase the volume by however many candy-colored projectiles he wants launched at his face. Simply knowing the secret language isn’t enough, though. Thanks to a little face-based security, you pretty much have to be [Harrison] or his doppelgänger to get any candy.

The Pi takes a picture, looks for faces, and rotates the turret base in that direction using three servos driven by Arduino Nanos. Then the Pi does facial landmark detection to find the target’s mouth hole before calculating the perfect parabola and firing. As [Harrison] notes in the excellent build video below, this machine uses a flywheel driven by a DC motor instead of being spring-loaded. M&Ms travel a short distance from the chute and hit a flexible, spinning disc that flings them like a pitching machine.

We would understand if you didn’t want your face involved in a build with Alexa. It’s okay — you can still have a voice-controlled candy cannon.

We’ve seen a lot of practical machines built using Lego. Why not? The bricks are cheap and plentiful, so if they can get the job done, who cares if they look like a child’s toy? Apparently, not [Yuksel Temiz]. He’s an engineer for IBM whose job involves taking pictures of microscopic fluidic circuits. When he wasn’t satisfied with the high-power $10,000 microscopes he had, he built his own. Using Lego. How are the pictures? Good enough to appear in many scientific journals.

Clearly, the microscope doesn’t just contain Lego, but it still came in at under $300. According to an interview from Futurism, the target devices are reflective which makes photographing them straight-on difficult. After experimenting with cameras on tripods, [Yuksel] decided he could build his own specialized device. You can see a video of the devices in question and some of the photographs below.

According to the same interview, it took several prototypes to get it right. The first prototype didn’t use Lego but was 3D printed. However, in a quest to make the microscope more modular and configurable, [Yuksel] raided the toy box.

The open source microscope is fully motorized, modular, and uses a Raspberry Pi with an 8-megapixel camera to capture images. An Arduino controls stepper motors and the lighting. The second video, below, shows the construction, and you can find documentation on IBM’s GitHub repository.

Not that we haven’t seen custom microscope builds before. If you prefer 3D printing, this might get you started.

At this point, society has had over three decades to get used to the Blue Man Group. Maybe that’s why we’re less disturbed by [Graham Jessup]’s face-tracking Watchman than we should be. Either that, or it’s because it reminds us of Data from Star Trek: The Next Generation. Frankly, this is just way too cool to be dismissed out of hand as creepy.

The Watchman finds faces via video feed from a camera module positioned in his forehead as a third eye. The camera is connected to a Pi Zero that’s wearing a Google AIY vision bonnet. The Pi translates the face locations into servo positions and feeds them to an Arduino UNO located in the frontal lobe region to move the eyeballs and lids accordingly.

[Graham] had a bit of trouble with tracking accuracy at first, so he temporarily replaced the pupils with 5 mW lasers and calibrated them by tracking a printed stand-in of his head to avoid burning out his retinas.

This project builds on previous work by [Tjahzi] and the animatronic eye movements of [Will Cogley]. We can only imagine how awesome the Watchman would look with a pair of [Will]’s incredibly realistic eyeballs. Either way, we would totally trust the Watchman to defend our modest supply of toilet paper in the coming weeks. Check out a brief demo after the break, and a whole lot more clips on [Graham]’s site.

Via reddit

It probably doesn’t surprise you to hear there are tens of thousands of web-connected cameras all over the world that are set to take the default credentials. Actually, there are probably more than that out there, but we can assure you that at least 70,000 or so are only a click away. With this project, [carolinebuttet] proves that it’s quite possible to make art from our rickety, ridiculous surveillance state — and it begins with a peephole perspective.

The peephole in your own front door grants you the inalienable right to police your porch, stoop, or patch of carpet in the apartment building’s hallway while going mostly undetected. In Virtual Peephole, the peephole becomes a voyeuristic virtual view of various corners of the world.

Slide aside the cover, and an LDR connected to an Arduino Micro detects the change in light level. This change makes the Micro send a key press to a Raspberry Pi, which fetches a new camera at random and displays it on a screen inside the box. You can peep a brief demo after the break, followed by a couple of short build/walk-through videos.

If you’re a peephole people watcher, put a camera in there and watch from anywhere.

Via Adafruit

Want to see something super cool? Go grab your copy of Make: Vol. 68 and download the Digi-Key AR Guide to Boards app, then put them together to watch real magic happen. 

Read more on MAKE

The post Make’s Guide to Boards Has a Hidden Secret! appeared first on Make: DIY Projects and Ideas for Makers.

[Tijmen Schep] sends in his project, Candle Smart Home, which is an exhibit of 12 smart home devices which are designed around the concepts of ownership, open source, and privacy.

The central controller runs on a Raspberry Pi which is running Mozilla’s new smart home operating system. Each individual device is Arduino based, and when you click through on the site you get a well designed graphic explaining how to build each device. The devices them

It’s also fun to see how many people worked together on this project and added their own touch. Whether it’s a unique covering for the devices or a toggle switch that can toggle itself there’s quite a few personal touches.

As anyone who’s had the sneaking suspicion that Jeff Bezos was listening in to their conversations, we get the need for this. We also love how approachable it makes hacking your own hardware. What are your thoughts?

[Julien] is one of those cool dads who shows his love with time invested rather than money spent. His daughter plays the harp, and you would not believe the price of concert harps. Even the cheap ones are several thousand USD. So naturally, he decided he would build her a MIDI concert harp from the ground up.

This plucky work in progress uses a strain gauge and an AD620 amplifier on every string to detect the tension when plucked. These amplifiers are connected to Arduinos, with an Arduino every nine strings. The Arduinos send MIDI events via USB to a Raspberry Pi, which is running the open synth platform Zynthian along with Pianoteq.

The harp is strung with guitar strings painted with silver, because he wanted capacitive touch support as well. But he scrapped that plan due to speed and reliability issues. Strain past the break to check out a brief demo video.

[Julien] used strings because he wanted to anchor the harpist in tactility. But you’re right; many if not most MIDI harps use lasers.

If you treat your Pi as a wearable or a tablet, you will already have a battery. If you treat your Pi as a desktop you will already have a plug-in power supply, but how about if you live where mains power is unreliable? Like [jwhart1], you may consider building an uninterruptible power supply into a USB cable. UPSs became a staple of office workers when one-too-many IT headaches were traced back to power outages. The idea is that a battery will keep your computer running while the power gets its legs back. In the case of a commercial UPS, most generate an AC waveform which your computer’s power supply converts it back to DC, but if you can create the right DC voltage right to the board, you skip the inverting and converting steps.

Cheap batteries develop a memory if they’re drained often, but if you have enough space consider supercapacitors which can take that abuse. They have a lower energy density rating than lithium batteries, but that should not be an issue for short power losses. According to [jwhart1], this quick-and-dirty approach will power a full-sized Pi, keyboard, and mouse for over a minute. If power is restored, you get to keep on trucking. If your power doesn’t come back, you have time to save your work and shut down. Spending an afternoon on a power cable could save a weekend’s worth of work, not a bad time-gamble.

We see what a supercap UPS looks like, but what about one built into a lightbulb or a feature-rich programmable UPS?



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