Before smartphones exploded on the scene in the late 00s, there was still a reasonable demand for pocket-sized computers that could do relatively simple computing tasks. Palm Pilots and other PDAs (Personal Digital Assistants) were all the rage in the ’90s and early ’00s, although for cutting-edge tech from that era plenty of these devices had astronomical price tags. This Arduino-based PDA hearkens back to that era, albeit with a much more accessible parts list.

The build is based around an Arudino Nano with an OLED screen and has the five necessary functions for a PDA: calculator, stopwatch, games, phonebook, and a calendar. With all of these components on such a small microcontroller, memory quickly became an issue when using the default libraries. [Danko] uses his own custom libraries in order to make the best use of memory which are all available on the project’s GitHub page. The build also includes a custom PCB to keep the entire pocket computer pocket-sized.

There are some other features packed into this tiny build as well, like the breakout game that can be played with a potentiometer. It’s an impressive build that makes as much use of the microcontroller’s capabilities as is possible, and if you enjoy projects where a microcontroller is used as if it is a PC take a look at this Arduino build with its own command-line interface.

Something like 99% of the people on the road at any given moment will consider themselves an above-average driver, something that’s as statistically impossible as it is easily disproven by casual observation. Drivers make all kinds of mistakes, but perhaps none as annoying and avoidable as failure to use their turn signal. This turn signal monitor aims to fix that, through the judicious use of negative feedback.

Apparently, [Mark Radinovic] feels that he has a predisposition against using his turn signal due to the fact that he drives a BMW. To break him of that habit, one that cost him his first BMW, he attached Arduino Nano 33 BLEs to the steering wheel and the turn signal stalk. The IMUs sense the position of each and send that over Bluetooth to an Arduino Uno WiFi. That in turn talks over USB to a Raspberry Pi, which connects to the car’s stereo via Bluetooth to blare an alarm when the steering wheel is turned but the turn signal remains untouched. The video below shows it in use; while it clearly works, there are a lot of situations where it triggers even though a turn signal isn’t really called for — going around a roundabout, for example, or navigating a sinuous approach to a drive-through window.

While [Mark] clearly built this tongue firmly planted in cheek, we can’t help but think there’s a better way — sniffing the car’s CANbus to determine steering angle and turn signal status comes to mind. This great workshop on CANbus sniffing from last year’s Remoticon would be a great place to start if you’d like a more streamlined solution than [Mark]’s.

[via Tom’s Hardware]

Lightning is a powerful and seemingly mysterious force of nature, capable of releasing huge amounts of energy over relatively short times and striking almost at random. Lightning obeys the laws of physics just like anything else, though, and with a little bit of technology some of its mysteries can be unraveled. For one, it only takes a small radio receiver to detect lightning strikes, and [mircemk] shows us exactly how to do that.

When lightning flashes, it also lights up an incredibly wide spectrum of radio spectrum as well. This build uses an AM radio built into a small integrated circuit to detect some of those radio waves. An Arduino Nano receives the signal from the TA7642 IC and lights up a series of LEDs as it detects strikes in closer and closer proximity to the detector. A white LED flashes when a strike is detected, and some analog circuitry supports an analog galvanometer which moves during lightning strikes as well.

While this project isn’t the first lightning detector we’ve ever seen, it does have significantly more sensitivity than most other homemade offerings. Something like this would be a helpful tool to have for lifeguards at a pool or for a work crew that is often outside, but we also think it’s pretty cool just to have around for its own sake, and three of them networked together would make triangulation of strikes possible too.

A beach is always a relaxing summer vacation destination, a great place to hang out with a drink and a book or take a swim in the ocean. For those who need a more active beach-going activity with an electronics twist, though, metal detecting is always a popular choice too. And, of course, with an Arduino and some know-how it’s possible to build a metal detector that has every feature you could want from even a commercial offering.

This build comes to us from [mircemk] who built this metal detector around an Arduino Nano and uses a method called induction balance detection to find metal. Similar to how radar works, one coil sends out a signal and the other listens for reflections back from metal objects underground. Building the coils and determining their resonant frequency is the most important part of this build, and once that is figured out the rest of the system can be refined and hidden treasure can easily be unearthed.

One of the more interesting features of this build is its ability to discriminate between ferrous and non-ferrous metals, and it can detect large metal objects at distances of more than 50 cm. There are improvements to come as well, since [mircemk] plans to increase power to the transmission coil which would improve the range of the device. For some of [mircemk]’s other metal detectors, be sure to check out this one which uses a smartphone to help in the metal detection process.

Have you ever heard of a Centurion minicomputer? If not, don’t feel bad — we hadn’t either, until [David Lovett] stumbled upon a semi-complete version of the 1980-ish mini in all its wood-trimmed, dust-encased glory. And what does a hacker do with such an acquisition but attempt to get it going again?

Of course, getting a machine from the Reagan administration running is not without its risks, including the chance of losing whatever is on the machine’s many ROM chips forever. When finding a commercial ROM reader supporting the various chips proved difficult, [David] decided to build his own. The work was eased considerably by the fact that he had managed to read one chip in a commercial reader, giving him a baseline to compare his circuit against. The hardware is straightforward — a 12-bit counter built from a trio of cascaded 74LS161s to step through addresses, plus an Arduino Nano to provide clock pulses and to read the data out to the serial port.

The circuit gave the same results as the known good read, meaning results would be valid for the rest of the chips. The breadboard setup made supporting multiple ROM pinouts easy, even for the chips that take -9 volts. What exactly the data on the ROMs mean, if anything, remains a mystery, but at least it’s backed up now.

Before anyone notes the obvious, yes, [David] could have used a 555 to clock the reader — perhaps even this one. We’d actually have loved that, but we get it — sometimes you just need to throw an Arduino at a job and be done with it.

The inner machinations of the mind of cryptocurrency markets are an enigma. Even traditional stock markets often seem to behave at random, to the point that several economists seriously suggest that various non-human animals might outperform one market or another just by random chance alone. The classic example is a monkey picking stocks at random, but in the modern world the hamster [Mr Goxx] actively trades crypto from inside his hamster cage.

[Mr Goxx]’s home comprises a normal apartment and a separate office where he can make his trades. The office contains an “intention wheel” where he can run in order to select a currency to trade, and two tunnels that [Mr Goxx] can use to declare his intention to buy or sell the currency he selected with the wheel. The wheel is connected to an Arduino Nano with an optical encoder, and the Nano also detects the hamster’s presence in the “buy” or “sell” tunnel and lights up status LEDs when he wants to execute a trade. The Nano also communicates with an intricate Java program which overlays information on the live video feed and also executes the trades in real life with real money.

Live updates are sent directly both on Twitter and Reddit, besides the live Twitch stream of [Mr Goxx] we linked above. The stream only shows his office and not his apartment, and he’s mostly active at night (Berlin time). But we can’t wait for his random walks to yield long-term results which can be analyzed for years to come. In the meantime we’ll see if others have been able to make any profits in crypto with any less-random methods.

Electric vehicles are becoming more and more common on the road, but when they’re parked in the driveway or garage there are still some kinks to work out when getting them charged up. Sure, there are plenty of charging stations on the market, but they all have different features, capabilities, and even ports, so to really make sure that full control is maintained over charging a car’s batteries it might be necessary to reach into the parts bin and pull out a trusty Arduino.

This project comes to us from [Sebastian] who needed this level of control over charging his Leaf, and who also has the skills to implement it from the large high voltage switching contactors to the software running its network connectivity and web app. This charging station has every available feature, too. It can tell the car to charge at different rates, and can restrict it to charging at different times (if energy is cheaper at night, for example). It is able to monitor the car’s charge state and other information over the communications bus to the vehicle, and even has a front-end web app for monitoring and controlling the device.

The project is based around an Arduino Nano 33 IoT with all of the code available on the project’s GitHub page. While we would advise using extreme caution when dealing with mains voltage and when interfacing with a high-ticket item like an EV, at first blush the build looks like it has crossed all its Ts and might even make a good prototype for a production unit in the future. If you don’t need all of the features that this charging station has, though, you can always hack the car itself to add some more advanced charging features.

Since the first of our ancestors discovered that banging a stick on a hollow log makes a jolly sound, we hominids have been finding new and unusual ways to make music. We haven’t come close to tapping out the potential for novel instruments, but then again it’s not every day that we come across a unique instrument and a new sound, as is the case with this string-plucking robot harp.

Named “Greg’s Harp” after builder [Frank Piesik]’s friend [Gregor], this three-stringed instrument almost defies classification. It’s sort of like a harp, but different, and sort of like an electric guitar, but not quite. Each steel string has three different ways to be played: what [Frank] calls “KickUps”, which are solenoids that strike the strings; an “eBow” coil stimulator; and a small motor with plastic plectra that pluck the strings. Each creates a unique sound at the fundamental frequency of the string, while servo-controlled hoops around each string serve as a robotic fretboard to change the notes. Sound is picked up by piezo transducers, and everything is controlled by a pair of Nanos and a Teensy, which takes care of MIDI duties.

Check out the video below and see if you find the sound both familiar and completely new. We’ve been featuring unique instruments builds forever, from not-quite-violins to self-playing kalimbas to the Theremincello, but we still find this one enchanting.

Desperate times call for desperate measures, and while making your own medical equipment isn’t normally advisable, Johnny Lee’e project explores how to turn a CPAP machine into a ventilator.

The idea is that since these machines are basically just blowers controlled by a brushless DC motor, an Arduino Nano equipped with an electonic speed controller could allow it to act as a one.

Such a setup has been shown to provide more than enough pressure for a ventilator used on COVID-19 patients. This device has in no way been evaluated or approved for medical use, but it does provide a starting point for experimentation.

You can find additional details on Lee’s GitHub page.

Touching your face is a subconscious behavior that we all do, and it is also an easy way to pick up illnesses like the coronavirus and flu. However, like many infectious diseases, proper hygiene can help reduce your risk. With this in mind, Nick Bild designed a simple solution in the form of a modified pair of glasses to provide a subtle reminder not to go near your eyes, mouth, and nose.

The project, which Bild calls Sentinel, consists of an ultrasonic sensor mounted on top of the bridge and an Arduino Nano along the temple. Whenever a hand (or object) is detected in close proximity to the face, a red warning LED lights up in the wearer’s peripheral vision.