Planet Arduino

Introduced in 1984, the Psion Organiser series defined the first generation of electronic organizers or PDAs (personal digital assistants). Even though these devices are now over 30 years old, the Psion Organiser scene is alive and well: with new hardware and software is still being developed by enthusiasts the world over.

One of those enthusiasts is [James Stanley], who designed and built a USB interface for the Psion Organiser II. Although a “CommsLink” module providing an RS-232 port was available back in the day, it’s become hard to find, inspiring [James] to design a completely new module based on an Arduino Nano. Hooking it up to the Psion’s data bus was a simple matter of wiring up the eight data lines to the Nano’s GPIO ports. A set of series resistors served to prevent bus contention without having to add glue logic.

Getting the software working was a bit more difficult: the Organiser’s native OPL programming language doesn’t allow the user to directly access the expansion port’s memory address, so [James] had to write a routine in HD6303 machine code to perform the read, then call that routine from OPL to display the result on the screen. Currently, the routine only supports reading data from the Arduino, but extending it to a bidirectional interface should be possible too.

Finally, [James] designed and 3D printed a neat enclosure for the Arduino-USB interface, which makes it look almost as sleek as the original CommsLink module. Perhaps with a bit of further development, this could turn into another way to connect old Psions to the internet. We’ve also featured a new type of Datapak to enhance the Organiser’s memory.

Thanks for the tip, [SaratogaJerry]!

One of the problems with a classic Turing machine is the tape must be infinitely long. [Mark’s] Turing Ring still doesn’t have an infinite tape, but it does make it circular to save space. That along with a very clever and capable UI makes this one of the most usable Turing machines we’ve seen. You can see a demo in the video below.

The device uses an Arduino Nano, a Neopixel ring, an encoder, and a laser-cut enclosure that looks great. The minimal UI has several modes and the video below takes you through all of them.

You can even store tapes to EEPROM or the serial port, so that’s even more practical. Of course, you might wonder what practicality is a Turing machine? The honest answer is not much, but on the bright side, this one also has a clock mode so even when you aren’t explaining how a Turing machine works, it will make a good conversation piece.

We were impressed with the lettering on the case in addition to the simplicity of the user interface. [Mark] had won the LED ring in a competition so the total cost of this — to him — was low, but it wouldn’t be too much even if you bought all the pieces.

This one is certainly more compact than the last Turing machine we looked at. If you need a refresher on Turing machines and why they matter, here’s some reading for you.

You know, we were just discussing weird and/or obsolete audio formats in the writers’ dungeon the other day. (By the way, have you ever bought anything on DAT or MiniDisc?) While vinyl is hardly weird or (nowadays) obsolete, the fact that this Bluetooth record player by [JGJMatt] is so modern makes it all the more fantastic.

Not since the Audio-Technica Sound Burger, or Crosley’s semi-recent imitation, have we seen such a portable unit. But that’s not even the most notable part — this thing runs inversely to normal record players. Translation: the record stands still while the the player spins, and it sends the audio over Bluetooth to headphones or a speaker.

Inside this portable player is an Arduino Nano driving a 5 VDC motor with a worm gear box. There really isn’t too much more to this build — mostly power, a needle cartridge, and a Bluetooth audio transmitter. There’s a TTP223 touch module on the lid that allows [JGJMatt] to turn it off with the wave of a hand.

[JGJMatt] says this is a prototype/work-in-progress, and welcomes input from the community. Right now the drive system is good and the Bluetooth is stable and able, but the tone arm has some room for improvement — in tests, it only played a small section of the record and skidded and skittered across the innermost and outermost parts. Now, [JGJMatt] is trying two-part arm approach where the first bit extends and locks into position, and then a second arm extending from there and moves around freely.

Commercial record players can do more than just play records. If you’ve got an old one that isn’t even good enough for a thrift store copy of a Starship record, you could turn it into a pottery wheel or a guitar tremolo.

When you need to get some tasks done and are short on attention, it’s hard to beat a timer. But whenever you do, it feels pretty darn good. The problem is that when you don’t finish in time, what’s the punishment? There are no consequences baked into the Pomodoro Technique other than good ol’ guilt. Wouldn’t it be better if there was a bit of negative reinforcement involved?

[Hardware Unknown]’s Focus Flower never needs watering, at least not in the normal horticultural way. You will have to fill a reservoir, because this flower provides liquid motivation. No, it’s not a spirit spritzer, though we suppose you could turn it into an avant-garde vodka fountain when the novelty of water wears off, making this Pomodoro with a twist into more of a Bloody Mary. It’s a natural next step, especially if you were already into the hot sauce idea.

Operation Focus Flower is simple: just push the easy button to start the task timer, and the Arduino Nano attached will begin a countdown. Push the button again when you’re done, but if you don’t do it before the countdown is over, the plant squirts you with a steady, skin-blasting stream of water from a solenoid-driven flosser tip. An air compressor nearby is required, which blows the minimalist vibe a bit, but you could always stow that part underneath your desk.

The Focus Flower sure looks to be effective at the whole negative reinforcement thing. And it doesn’t leave you totally clueless — there’s a ring of LEDs around the base that show how much time is left. Whenever you do successfully hit the button in time, it will say ‘that was easy’ in one of 12 languages, hence all the flags. Do not miss the totally free infomercial below.

Maybe you want a more friendly way to manage your time — we understand. Meet the Pomodachi productivity pet.

Via the Arduino Blog

Student and hacker [prusteen] recently fell in love with the Pomodoro method of time management. That’s where you concentrate on your task for 25 minutes, then take a five-minute break, and repeat this four times with a longer break at the end. Initially, [prusteen] was keeping track on their phone, but hated having to change the timer value between Pomodoros and break times. In order to keep the flow mode engaged, [prusteen] came up with this darling little study buddy that does it all with the push of a button.

By default, this tomato shows the current time, which we think is a handy and often-overlooked feature of Pomodoro timer builds. Press that momentary switch on the front, and it starts counting upward to 25 minutes. Then it beeps in stereo through a pair of buzzers when the time is up, and automatically starts a five-minute break timer. Press it again and the display goes back to clock mode, although judging by the code, doing this will cancel the timer.

Inside the juicy enclosure is an Arduino Nano, an RTC, and a 7-segment display. We love the attention to detail here, from the little green leaves on top to the anatomically-correct dimple on the underside. And we always like to see lids that snap on with magnets. So satisfying. Check out the brief demo after the break, which unfortunately does not include any lid-snapping action.

Do you need more interaction with your Pomodoro timer? Build yourself a pomo-dachi instead.

Among the plethora of obsolete removable media there are some which are lamented, but it can be difficult to find those who regret the passing of the floppy disk. These flexible magnetic disks in hard plastic covers were a staple of computing until some time in the early 2000s, and their drives could be found by the crateload in any spares box. But what about today, when there’s a need for a real floppy drive and none is to be found? Enter [Acemi Elektronikci], with an Arduino Nano based floppy emulator, that plugs into the floppy port of a PC old enough to have one, and allows the easy use of virtual floppy disks.

Aside from the Nano it has an SD card and associated level shifter, and an SSD1306 i2c screen. Most of the Arduino’s lines drive the floppy interface, so the five-button control comes to a single ADC pin via a resistor ladder. He freely admits that it’s not a perfect cycle-exact emulator of original hardware and there may be machines or even operating systems that complain when faced with it, but for all that it is a useful tool. One of the machines that may have issues is the Amiga, but fortunately there’s a fix for that with a Raspberry Pi.

We never did crack open our Etch-a-Sketch, but we did scrape out a window large enough to really check out the mechanism inside. [MrLangford] is bringing the Etch-a-Sketch into the 21st century while at the same time, bringing an even bigger air of mystery, at least for the normies.

Instead of scraping aluminum powder off of plastic by driving a stylus on an x-y gantry with a pair of knobs, this bad boy uses rotary encoders to move the cursor around and put down squares of colored light. The familiar movements are there — the left knob moves the cursor left and right, and the right knob moves it up and down. But this wouldn’t be a 21st century toy without newfangled features. Push the left encoder down and it cycles through eight color choices, or push the right one down to go through them backwards. We hope one of the colors is setting it back to darkness in case you screw up. And while we’re dreaming up improvements, it would be awesome to add an accelerometer so you could shake it clear like a standard Etch-a-Sketch.

Inside the requisite red enclosure with white knobs are an Arduino Nano and a 16×16 RGB LED matrix. The enclosure is four sheets of 6mm MDF glued together, and we like the use of protoboard to distribute GND and 5 V in the name of keeping the thing slim.

If you’re not much of an artist, here’s a TV-sized Etch-a-Sketch build that can draw by itself.

Ok, we’ll come clean. [Design Build Destroy] didn’t really add any memory to his Arduino Nano. But he did get about 1.5K more program space when compared to the stock setup. The trick? On some Nano boards and clones, the bootloader is set to use a large block of reserved memory, but Optiboot only requires a fraction of that reserved memory. By reprogramming the bootloader and changing the configuration fuses, you can reclaim that unused memory.

Of course, you can’t easily overwrite the bootloader and fuses over the serial port to prevent you from bricking your device. The video below shows how to connect another Arduino to do the programming. You could also use any dedicated AVR programmer you happen to have. Oddly, the Uno already uses Optiboot with the same processors, and is set correctly and the video shows the differences in the configuration between the two in their default state.

Of course, depending on where you get your Nano devices and their age, you may already have this set up at which point you won’t gain anything, but you should be able to easily tell if you need to go through the steps or not. The same trick will probably work with any older Arduino boards you have laying around if Optiboot supports them. What can you do with the extra memory? Maybe speech recognition?

We’ve all been there. Your current project has hit a wall, or the next step will take days to complete, and you need something to do in the meantime. So you start a project that you envision will fit nicely in the gap, and then, inevitably, it doesn’t. Maybe it even takes so long that the original project gets finished first. So what? There’s nothing wrong with that, especially when the filler project turns out as well as this drink temperature monitor disguised as a circuit sculpture (video, embedded below). Just put your mug on the coaster, and the weight of it activates a hidden switch, which causes the sculpture to display its secret LEDs.

[MakeFunStuff] wanted to make something that looked less like a circuit and more like art, while building a tool that could determine the relative hotness of a beverage. Such a a useful circuit sculpture sounds like a tall order to us, but [MakeFunStuff] pulled it off with finesse and style.

The circuit is based around this Sputnik-looking standalone IR temperature sensor which, as [MakeFunStuff] aptly describes, is “a single-pixel infrared camera that picks up everything in a 90° cone starting at the sensor.”

[MakeFunStuff] paired this easy-to-use sensor with an Arduino Nano and five LEDs that show how hot a beverage is on a scale from 1 to 5. The sensor is hidden in plain sight, suspended from the top of the brass rod sculpture and blending in perfectly. We love that the LEDs are hidden behind a thin layer of carefully-drilled wood and agree that a drill press would have been much easier.

The code is set up for just about every temperature scale from Celsius to Rømer, so that solves that argument. [MakeFunStuff] went with the Kelvin scale because science. Our favorite thing about this video is that [MakeFunStuff] shared their failures and fixes as they built their way toward answering the questions of how to suspend the sensor over the drink, and how best to display the heat level while hiding the electronics. Go grab a hot cup of something and check it out after the break while you let it cool off the normie way.

We admit that we would likely zone out while waiting for the LEDs to disappear. Here’s a smart coaster that uses an ESP8266 to send a message to Discord when your beverage has reached the perfect drinking temperature.

Thanks for the hot tip, [Perry]!

Portable air conditioning units are a great way to cool off a space during the hot summer months, but they require some place to blow the heat they’ve removed from your room. [VincentMakes] got a portable AC unit for his home, but he found that the place he wanted to put it was too far from the only window he could use to dump the hot air. Having too long of a duct on the hot air exhaust increases the back pressure on the fan which could cause it to prematurely fail, so [Vincent] used an extractor fan to automatically give is AC unit’s exhaust a boost on its way to the window.

Because his AC can operate at low, medium, and high speeds, he chose an extractor fan that also supported multiple speeds and took care to match the airflow of the AC and extractor fan to avoid putting too much strain on either fan. He designed a system to automatically set the speed of the boosting fan to match that of the AC using a Hall effect current sensor to measure the AC unit’s power draw and an Arduino Nano for control. A custom PCB interfaces the Nano to the Hall Sensor and control relays, and we have to applaud [Vincent] for keeping the +5V DC and 230V AC far, far away from each other. In addition to this fine electronics work, [Vincent] also built an enclosure for the fan controller that allows the fan to be mounted on top at an angle, which helps avoid having hard bends in the exhaust duct.

If this has you thinking about smart air conditioners to keep cool this summer, check out this ESP8266-powered smart AC system, or this Raspberry Pi-based system that controls both AC and blinds!