arduino

2909 Articles

Arduino Magnetic Board Is Anything But Boring

June 17, 2020 by 3 Comments

Magnets (especially those ball magnets!) are endlessly fascinating, aren’t they? It’s almost dangerous to combine them with LEDs, because how are you supposed to get anything done with something like [andrei.erdei]’s Arduino Magnetic Board beckoning from beyond your keyboard?

This tons-of-fun board uses ball magnets to light up RGB LEDs as they roll around on the sexy Plexiglas field. Underneath the LED matrix is an orchestra of 36 reed switches — those little glass gas-filled grains of rice with axial leads that snap together or fly apart in the presence of magnetic fields. The LEDs are controlled with an Arduino Pro Mini, and so is the 8Ω speaker for sound effects.

[andrei.erdei] has already developed a few applications for this delightful desk toy, and they’re all on GitHub. There’s a chase game that involves tilting the board to catch the next red dot with the magnet, a light painting game, and a sequencer that mimics the ToneMatrix. Roll past the break to check out the series of short demo videos.

Want to play with reed switches but can’t source any at the moment? You could just make them yourself.

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Arduino Reduces Heating Costs

June 16, 2020 by 29 Comments

While almost everyone has a heater of some sort in their home, it’s fairly unlikely that the heat provided by a central heating system such as a furnace is distributed in an efficient way. There’s little reason to heat bedrooms during the day, or a kitchen during the night, but heating systems tend to heat whole living space regardless of the time of day or the amount of use. You can solve this problem, like most problems, with an Arduino.

[Karl]’s build uses a series of radiator valves to control when each room gets heat from a boiler. The valves, with a temperature monitor at each valve, are tied into a central Arduino Mega using alarm wiring. By knowing the time of day and the desired temperature in each room, the Arduino can control when heat is applied to each room and when it is shut off, presumably making the entire system much more efficient. It also has control over the circulating pump and some of the other boiler equipment.

Presumably this type of system could be adapted to a system which uses a furnace and an air handler as well, although it is not quite as straightforward to close vents off using a central unit like this as it is to work with a boiler like [Karl] has. With careful design, though, it could be done. Besides replacing thermostats, we can’t say we’ve ever seen this done before.

Thanks to [SMS] for the tip!

Electronic Connect Four Has No Pieces To Lose

June 15, 2020 by 6 Comments

Recreating classic games in software is a great way to get better at coding or learn to code in the first place. If you do it in hardware though, you’ll gain a lot more than coding skills. Just ask [Kelly] and [Jack] did, when they built this Arduino-based electronic Connect Four for a school project.

We love that their interpretation manages to simplify game play and make it more fun than the original version. All the players have to do is turn it on and start pushing the arcade buttons along the bottom to choose the column where they want to make a play. The LEDs animate from top to bottom to imitate the plastic disc dropping down through the board. If a win is detected — four in a row of the same color going any direction — the board fills up with the winning color and the game starts over.

The state machine doesn’t currently do anything about tie situations, so there’s a reset button hidden on the side. As [Kelly] and [Jack] explain in their walk-through video after the break, that is something they would like to address in the future, along with making it possible to choose whatever battle color you want. We think a reset animation that mimics the look of the discs spilling out the bottom would be cool, too.

If you’ve never implemented a game on hardware before, something like this might be a bit daunting. May we suggest a game of 4×4 Tic Tac Toe instead?

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No Need For Speed With This Arduino-Based Inkjet Printer

June 13, 2020 by 17 Comments

When it comes to computers, it seems like the only thing that matters is speed. The more the better, in general, and the same applies to peripherals. We want the fastest network adapters, the fastest video card, and the fastest printer. So why in the world would anyone intentionally build a really slow inkjet printer? For art, of course.

At least that’s the story [HomoFaciens] tells us in the video below. His efforts are in support of a friend’s art project, which seeks to print slowly but continuously on a roll of paper. [HomoFaciens]’s printer is based on an H-P C6602 inkjet cartridge, one of those high-priced consumables that make buying a new printer more attractive than replacing them once depleted. After figuring out how to drive the printhead — 5 to 6 μs pulses of 18 volts through a ULN2803 Darlington array driver chip seemed to do the trick — he mounted everything to the gantry of an old 3D printer. It’s interesting to watch the images slowly being built up — something that printers usually hide from prying eyes — and to see how the DPI count of the printer can be increased by interlacing each printed line.

Near the end of the video, we get a glimpse of his “tattoo gun printer”, which reminded us of all the other cool things he’s done over the years. From a CNC machine made from paperclips and cardboard to an encoder made from a wheel of resistors, [HomoFaciens] has some interesting designs that you really should check out.

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Control A Motor With A Touchpad

June 10, 2020 by 11 Comments

There are a surprising wealth of parts inside of old laptops that can be easily scavenged, but often these proprietary tidbits of electronics will need a substantial amount of work to make them useful again. Obviously things such as hard drives and memory can easily be used again, but it’s also possible to get things like screens or batteries to work with other devices with some effort. Now, there’s also a way to reuse the trackpad as well.

This build uses a PS/2 touchpad with a Synaptics chip in it, which integrates pretty smoothly with an Arduino after a few pins on the touchpad are soldered to. Most of the work is done on the touchpad’s built in chip, so once the Arduino receives the input from the touchpad it’s free to do virtually anything with it. In this case, [Kushagra] used it to operate a stepper motor in a few different implementations.

If you have this type of touchpad lying around, all of the code and schematics to make it useful again are available on the project page. An old laptop in the parts bin is sure to have a lot of uses even after you take the screen off, but don’t forget that your old beige PS/2 mouse from 1995 is sure to have some uses like this as well.

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Light Up The Night With A Tetrahedral LED Hat

June 10, 2020 by 7 Comments

People get into electronics for all kinds of reasons, but we would guess that the ability to blink the blinkenlights is probably pretty high on the survey results. [Kuchbert] has been going to Deichkind shows for the last decade and has wanted to build one of the German techno-rap band’s signature tetrahedral LED hats for about as long.

Up inside the hat is an Arduino Nano driving WS2812B LEDs and a portable battery to power everything. Thanks to an HC-05 Bluetooth module, the show can be controlled with an Android app. The many, many holes in the acrylic panels were milled out, but they could just as easily be laser-cut, or if you have infinite patience, drilled by hand. The code is coming once it has been cleaned up a bit. Everything else you’d need is already there waiting. This helmet even has its own lil’ music video, which we’ve carefully beat-matched in after the break.

Naturally, this makes us think of all the Daft Punk helms that have blinked by on this blog over the years. This hand-soldered one might be the most meticulously made.

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Rotary Controller Dials In PC Volume

June 4, 2020 by 9 Comments

As wonderful as mechanical keyboards are, most of the pre-fab and group buy models out there have zero media controls. If you want rotary encoders and OLED screens to show what function layer you’re working in, you’ll probably have to build your own keyboard from the ground up.

Hackaday alum [Cameron Coward] got around this problem by building an electromechanical buddy for his keyboard that works as a volume control. Now that we don’t rely on them to make phone calls, rotary dials are a fun throwback to a time that seems simpler based on its robust and rudimentary technology. This one is from a lovely burnt orange Bell Trimline phone, which was peak rotary dial and one of the idea’s last gasps before tone dialing took over completely.

Operationally speaking, [Cameron] is reading in the dial’s pulses with an Arduino Nano and using a Python script to monitor the serial connection and translate the pulses to volume control. We like that this is isn’t a volume knob in the traditional sense — it’s a game of percentages. Dialing ‘2’ gives 20% volume across all programs, and ‘8’ raises it to 80% of maximum. Need to mute? Just dial ‘0’, and you’ll begin to understand why people wanted to move on from rotary dialing. It won’t take that long, but it’s not instant. Check out the demo after the break.

This isn’t the first time we’ve seen a rotary dial used to control volume, but that’s one of the minor selling points of this rotary cell phone.

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