arduino

2894 Articles

Enjoy Totality Every Day With This Personal Eclipse Generator

June 27, 2024 by 29 Comments

There have been a couple of high-profile solar eclipses lately, but like us, you probably missed the news of the one that passed over Munich in 2019. And every day since then, in fact, unless you were sitting in a particular spot: the couch of one [Bernd Kraus], who has his very own personal eclipse generator.

We’ll attempt to explain. Living in an apartment with a gorgeous western view of Munich is not without its cons, chief among which is the unobstructed exposure to the setting sun. Where most people would opt for a window treatment of some sort to mitigate this, [Bernd] felt that blotting out the entire view was a heavy-handed solution to the problem. His solution is a window-mounted X-Y gantry that dangles a cutout of the moon in just the right place to blot out the sun. An Arduino uses the time and date to calculate the position of the sun as it traverses the expansive window and moves the stepper motors to keep the moon casting its shadow in just the right place: on his face as he sits in his favorite spot on the couch.

There are a couple of time-lapse sequences in the video below, as well as a few shots of the hardware. We know this isn’t an actual coronagraph, but the effect is pretty cool, and does resemble an eclipse, at least in spirit. And it goes without saying that we applaud the unnecessary complexity embodied by this solution.

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A PCB business card that plays tic-tac-toe with red and blue LEDs.

2024 Business Card Challenge: Go Tic-Tac-Toe-to-Toe With Them

June 24, 2024 by 4 Comments

There is perhaps no more important time to have a business card than when you’re in college, especially near the end when you’re applying for internships and such. And it’s vital that you stand out from the crowd somehow. To that end, Electrical & Computer Engineer [Ryan Chan] designed a tidy card that plays tic-tac-toe.

Instead of X and O, the players are indicated by blue and red LEDs. Rather than having a button at every position, there is one big control button that gets pressed repeatedly until your LED is in the desired position, and then you press and hold to set it and switch control to the other player. In addition to two-player mode, the recipient of your card can also play alone against the ATMega.

The brains of this operation is an ATMega328P-AU with the Arduino UNO bootloader for ease of programming. Schematic and code are available if you want to make your own, but we suggest implementing some type of changes to make it your own. Speaking of, [Ryan]  has several next steps in mind, including charlieplexing the LEDs, using either USB-C or a coin cell for power, upgrading the AI, and replacing the control button with a capacitive pad or two. Be sure to check it out in action in the two videos after the break.

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An Arduino Nano Clone In A DIP-Sized Footprint

June 22, 2024 by 33 Comments

Nobody doubts the utility of the Arduino Nano and its many clones, and chances are good you’ve got at least one or two of the tiny dev boards within arm’s reach right now. But as small as it is, the board still takes up a fair amount of real estate, especially on solderless breadboards during the prototyping phase of a project. Wouldn’t it be nice to shrink down the Nano just a bit and regain a couple of rows for plugging in components and jumpers?

It looks like [Albert van Dalen] thought so, and he managed to get a Nano’s functionality — and then some — onto a DIP-26 footprint. The aptly named “Nano DIP,” which at 33 mm x 10 mm — about the same size as the ATmega328 on the Arduino Uno — will tickle the miniaturization fans out there. The board is built around an ATtiny3217 and has almost all of the Nano’s features, like a USB port, reset button, built-in LEDs, 5 V regulator, and preloaded bootloader. Its big extra feature is the 350-kilosamples-per-second 8-bit DAC, while sacrificing external crystal pins and a 3.3 V regulator.

To make the board cheap enough to manufacture, [Albert] elected a minimum component size of 0402, which made squeezing all the parts onto the board challenging. The MCU barely fits between the header pin pads, and the Micro USB jack had to be a vertical-mount type. It does the business, though, so if you’re looking to free up a little breadboard space, check it out.

Learning Morse Code With A DIY Trainer

June 22, 2024 by 17 Comments

Morse code, often referred to as continuous wave (CW) in radio circles, has been gradually falling out of use for a long time now. At least in the United States, ham radio licensees don’t have to learn it anymore, and the US Coast Guard stopped using it even for emergencies in 1999. It does have few niche use cases, though, as it requires an extremely narrow bandwidth and a low amount of power to get a signal out and a human operator can usually distinguish it even if the signal is very close to the noise floor. So if you want to try and learn it, you might want to try something like this Morse trainer from [mircemk].

While learning CW can be quite tedious, as [mircemk] puts it, it’s actually fairly easy for a computer to understand and translate so not a lot of specialized equipment is needed. This build is based around the Arduino Nano which is more than up for the job. It can accept input from any audio source, allowing it to translate radio transmissions in real time, and can also be connected to a paddle or key to be used as a trainer for learning the code. It’s also able to count the words-per-minute rate of whatever it hears and display it on a small LCD at the front of the unit which also handles displaying the translations of the Morse code.

If you need a trainer that’s more compact for on-the-go CW, though, take a look at this wearable Morse code device based on the M5StickC Plus instead.

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Arduino + TFT = Micro Star Chart

June 20, 2024 by 9 Comments

We always look at the round LCDs and wonder what to do with them other than, of course, a clock. Well, [shabaz] had a great idea: use it as a star map display. The project combines the Arduino, a round TFT, a GPS receiver, and some external flash memory to store data. You can get by without the GPS receiver or flash memory, but you’ll lose features if you do.

We like how he approached the problem. The project contains four major parts and he developed each part independently before integrating them into a whole. The four parts are: reading the GPS, driving the LCD, providing storage for star data, and determining the position of stars. The heavy lifting is done using some public domain code ported over. This code derives from a book called Astronomical Algorithms and uses the Yale Bright Star Catalog database.

The post mentions that the screen might well be a larger rectangular screen and we agree that would make this more usable. Now if you could cram it all into a watch, that might be different. If you want to play with the code, you can actually run the core on Linux. You’ll have to settle for a PNG output of the night sky, but that would be handy for debugging.

We have seen a star chart in a watch before. While this is more a star chart than a planetarium, we have no doubt the early planetarium builders would be suitably impressed.

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Tight Handheld CRT Asteroids Game Curses In Tuscan

June 12, 2024 by 5 Comments

How many Arduini does it take to make a tiny CRT Asteroids game? [Marco Vallegi] of MVV Blog’s answer: two. One for the game mechanics and one for the sound effects. And the result is a sweet little retro arcade machine packed tightly into a very nicely 3D printed case.

If you want to learn to curse like a Tuscan sailor, you can watch the two-part video series, embedded below, in its entirety. Otherwise, we have excerpted the good stuff out of the second video for you.

For instance, we love the old-school voice synthesis sound of the Speak and Spell. Here, playback is implemented using the Talkie library for Arduino, and [Marco] is using the BlueWizard software on a dated Macbook for recording and encoding. (We’d use the more portable Python Wizard ourselves.) Check out [Marco] tweaking the noise parameters here to get a good recording.

And since the Talkie Arduino library uses PWM on a digital output pin to create the audio, the high-frequency noise was freaking out his simple transistor amplifier. Here, [Marco] adds a feedback capacitor to cancel that high-frequency hash out.

The build needs to be quite compact, and the stacked-Arduino-with-PCB-case design is tight. And the 3D-printed case has a number of nice refinements that you might like. We especially like the use of thin veneers that cover the case all around with the build-plate’s surface texture, and the contrasting “Asteroids” logos are very nice.

All in all, this is a really fun build that’s also full of little details that might help you with your own projects. Heck, even if it just encourages you to play around with the Talkie library, it’s worth your time in our opinion. And while you’re at it, you can turn on the subtitles and pick up some vocab that’ll make your nonna roll over in her grave.

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Making Intel Mad, Retrocomputing Edition

June 9, 2024 by 20 Comments

Intel has had a deathgrip on the PC world since the standardization around the software and hardware available on IBM boxes in the 90s. And if you think you’re free of them because you have an AMD chip, that’s just Intel’s instruction set with a different badge on the silicon. At least AMD licenses it, though — in the 80s there was another game in town that didn’t exactly ask for permission before implementing, and improving upon, the Intel chips available at the time.

The NEC V20 CPU was a chip that was a drop-in replacement for the Intel 8088 and made some performance improvements to it as well. Even though the 186 and 286 were available at the time of its release, this was an era before planned obsolescence as a business model was king so there were plenty of 8088 systems still working and relevant that could take advantage of this upgrade. In fact, the V20 was able to implement some of the improved instructions from these more modern chips. And this wasn’t an expensive upgrade either, with kits starting around $16 at the time which is about $50 today, adjusting for inflation.

This deep dive into the V20 isn’t limited to a history lesson and technological discussion, though. There’s also a project based on Arduino which makes use of the 8088 with some upgrades to support the NEC V20 and a test suite for a V20 emulator as well.

If you had an original IBM with one of these chips, though, things weren’t all smooth sailing for this straightforward upgrade at the time. A years-long legal battle ensued over the contents of the V20 microcode and whether or not it constituted copyright infringement. Intel was able to drag the process out long enough that by the time the lawsuit settled, the chips were relatively obsolete, leaving the NEC V20 to sit firmly in retrocomputing (and legal) history.