A stack of PCB business cards that can play Snake on an 8x8 LED matrix.

2024 Business Card Challenge: Snakes On A Business Card

June 2, 2024 by Kristina Panos No comments

Once [Lambert the Maker] saw the Arduboy, he knew the thing was ripe for remixing into a business card with an 8×8 LED matrix instead of an OLED screen. [Lambert] already has a PCB business card for work, but it looks like it doesn’t do anything. So this Snake-playing card is for their personal information.

The brains of this operation is an STM32F0, which required a bit of finesse when it came to programming the LEDs. According to the datasheet, the max current through a given GPIO pin is 30 mA. The LEDs are running at 20 mA through the limiting resistor, so the code only turns on one LED at a time and makes sure the previous one is off first. The whole screen is updated every 125 ms, and persistence of vision takes care of making the animation look right.

In the short videos after the break, you’ll see a preview followed by brief videos on versions one and two. The prototype was built in 2020, when the board house only offered green PCBs with their assembly service. Fast forward to 2024, when the board house is now offering colors other than green.

Version two is actually thinner than a credit card, and features tiny buttons instead of cap-sense pads for input. [Lambert] also added a floating ADC pin that acts as a random number generator, placing the apple in a new location every time the game is powered on.

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A PCB business card with a built-in 4x4 tic-tac-toe game on the back.

2024 Business Card Contest: A Game For Two

May 30, 2024 by Kristina Panos 2 Comments

If you want to make a good first impression on someone, it seems like the longer you can keep them talking, the better. After all, if they want to keep talking, that’s a pretty good sign that even if you don’t become business partners, you might end up friends. What better way to make an acquaintance than over a friendly game of tic-tac-toe?

This one will probably take them by surprise, being a 4×4 matrix rather than the usual 3×3, but that just makes it more interesting. The front of the card has all the usual details, and the back is a field of LEDs and micro switches. Instead of using X and O, [Edison Science Corner] is using colors — green for player one, and red for player two. Since playing requires the taking of turns, the microcontroller lights up green and red with alternating single-button presses.

Speaking of, the brains of this operation is an ATMega328P-AU programmed with Arduino. If you’d like to make your own tic-tac-toe business card, the schematic, BOM, and code are all available. Be sure to check out the build and demo video after the break.

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2024 Business Card Challenge: Adding Some Refinement To Breadboard Power Supplies

May 26, 2024 by Bryan Cockfield 6 Comments

For small electronics projects, prototyping a design on a breadboard is a must to iron out kinks in the design and ensure everything works properly before a final version is created. The power supply for the breadboard is often overlooked, with newcomers to electronics sometimes using a 9V battery and regulator or a cheap USB supply to get a quick 5V source. We might eventually move on to hacking together an ATX power supply, or the more affluent among us might spring for a variable, regulated bench supply, but this power supply built specifically for breadboards might thread the needle for this use case much better than other options.

The unique supply is hosted on a small PCB with two breakout rails that connect directly to the positive and negative pins on a standard-sized breadboard. The power supply has two outputs, each of which can output up to 24V DC and both are adjustable by potentiometers. To maintain high efficiency and lower component sizes, a switch-mode design is used to provide variable DC voltage. A three-digit, seven-segment display at the top of the board keeps track of whichever output the user selects, and the supply itself can be powered by a number of inputs, including USB-C or lithium batteries.

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The 2024 Business Card Challenge Starts Now

May 7, 2024 by Elliot Williams 22 Comments

If you want to make circuits for a living, what better way to impress a future employer than to hand them a piece of your work to take home? But even if you’re just hacking for fun, you can still turn your calling into your calling card.

We are inviting you to submit your coolest business card hacks for us all to admire, and the top three entries will win a $150 DigiKey shopping spree. If your work can fit on a business card, create a project page for it over on Hackaday.io and enter it in the 2024 Business Card Contest. Share your tiny hacks!

To enter, create a project for your hacked business card over at Hackaday IO, and then enter it into the 2024 Business Card Challenge by selecting the pulldown on the left. It’s that easy.

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2024 Home Sweet Home Automation: The Winners Are In

April 30, 2024 by Tom Nardi 13 Comments

Home automation is huge right now in consumer electronics, but despite the wide availability of products on the market, hackers and makers are still spinning up their own solutions. It could be because their situations are unique enough that commercial offerings wouldn’t cut it, or perhaps they know how cheaply many automation tasks can be implemented with today’s microcontrollers. Still others go the DIY route because they’re worried about the privacy implications of pushing such a system into the cloud.

Seeing how many of you were out there brewing bespoke automation setups gave us the idea for this year’s Home Sweet Home Automation contest, which just wrapped up last week. We received more than 80 entries for this one, and the competition was fierce. Judging these contests is always exceptionally difficult, as nearly every entry is a standout accomplishment in its own way.

But the judges forged ahead valiantly, and we now have the top three projects which will be receiving $150 in store credit from the folks at DigiKey.

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2024 Home Sweet Home Automation: Spray Bottle Turret Silences Barking

April 26, 2024 by Kristina Panos 11 Comments

Ah, dogs. They sure like to bark, don’t they? [rrustvold]’s dog likes to bark at the door when a package arrives. Or when someone walks by the house, or whenever the mood strikes, really. To solve the barking issue, at least near the front door, [rrustvold] built a spray bottle turret to teach the dog through classical conditioning.

As you can see from the image, it’s all about pulling the trigger on a standard spray bottle at the right time. This machine only sprays when two conditions are met: it hears noise (like barking) and detects motion (like overzealous tail wagging). It also has heat-seeking abilities thanks to a Raspberry Pi thermal camera.

To do the actual spraying, there’s a DC motor mounted behind the bottle which turns a pulley that’s mounted to its shaft. Around the pulley is a string that wraps around the spray bottle’s trigger. To complete the build, everything is mounted on a lazy Susan so there’s nowhere for Fido to hide-o.

If you’ve a dog whose bite is worse than its bark, consider building a custom dog door to keep it out of the cat box.

The 2024 Home Sweet Home Automation contest has officially wrapped — we’re counting the votes now, so stay tuned for an announcement about the winners shortly.

2024 Home Sweet Home Automation: [HEX]POD – Climate Tracker And Digital Nose

March 27, 2024 by Dave Rowntree 10 Comments

[eBender] was travelling India with friends, when one got sick. Unable to find a thermometer anywhere during COVID, they finally ended up in a hospital. After being evacuated back home, [eBender] hatched an idea to create a portable gadget featuring a few travel essentials: the ability to measure body temperature and heart rate, a power bank and an illumination source. The scope evolved quite a lot, with the concept being to create a learning platform for environmental multi-sensor fusion. The current cut-down development kit hosts just the air quality measurement components, but expansion from this base shouldn’t be too hard.

ML for Hackers: Fiddle with that Tensor Flow

This project’s execution is excellent, with a hexagon-shaped enclosure and PCBs stacked within. As everyone knows, hexagons are the bestagons. The platform currently hosts SCD41 and SGP41 sensors for air quality, a BME688 for gas detection, LTR-308 for ambient light and motion, and many temperature sensors.

On top sits a 1.69-inch IPS LCD, with an OLED display on the side for always-on visualization. The user interface is completed with a joystick and a couple of buttons. An internal blower fan is ducted around the sensor array to pull not-so-fresh air from outside for evaluation. Control is courtesy of an ESP32 module, with the gory details buried deep in the extensive project logs, which show sensors and other parts being swapped in and out.

On the software side, some preliminary work is being done on training TensorFlow to learn the sensor fusion inputs. This is no simple task. Finally, we would have a complete package if [eBender] could source a hexagonal LCD to showcase that hexagon-orientated GUI. However, we doubt such a thing exists, which is a shame.

There are many air quality sensors on the market now, so we see a few hacks based on them, like this simple AQ sensor hub. Let’s not forget the importance of environmental CO2 detection; here’s something to get you started.