Tiny Operating System For Tiny Computer

Before the World Wide Web became ubiquitous as the de facto way to access electronic information, there were many other ways of retrieving information online. One of the most successful of these was Minitel, a French videotex service that lasted from 1980 all the way until 2012. But just because the service has been deactivated doesn’t mean its hardware can’t be used for modern builds like this Arduino-based operating system. (Google Translate from French)

Called ZARDOS, the operating system is built to run on an Arduino MEGA although a smaller version is available for the Uno. The Arduino is connected by a serial cable to the Minitel terminal. It can take input from a keyboard and PS/2 mouse and displays video on the terminal screen with the same cable. There is functionality built-in for accessing data on a cartridge system based on SD cards which greatly expands the limited capabilities of the Atmel chip as well, and there is also support for a speaker and a Videotex printer.

Even though the build uses a modern microcontroller, it gives us flashbacks to pre-WWW days with its retro terminal. All of the code is available on the project site for anyone looking to build an Arduino-based operating system, although it will take a little bit of hardware hacking to build a Minitel terminal like this. Either way, it’s a great way to revive some antique French hardware similar to a build we’ve seen which converts one into a Linux terminal.

Thanks to [troisieme_type] for the tip!

Arduino Reduces Heating Costs

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!

Arduino And Pi Share Boardspace

A Raspberry Pi Zero (W) and Arduino are very different animals, the prior has processing power and connectivity while the latter has some analog to digital converters (ADCs) and nearly real-time reactions. You can connect them to one another with a USB cable and for many projects that will happily wed the two. Beyond that, we can interface this odd couple entirely through serial, SPI, I2C, and logic-level signaling. How? Through a device by [cburgess] that is being called an Arduino shield that supports a Pi0 (W). Maybe it is a cape which interfaces with Arduino. The distinction may be moot since each board has a familiar footprint and both of them are found here.

Depending on how they are set up and programmed, one can take control over the other, or they could happily do their own thing and just exchange a little information. This board is like a marriage counselor between a Raspberry Pi and an Arduino. It provides the level-shifting so they don’t blow each other up and libraries so they can speak nicely to one another. If you want to dig a bit deeper into this one, design files and code examples are on available.

Perhaps we’ll report on this board at the heart of a pinball machine retrofit, a vintage vending machine restoration, or maybe a working prop replica from the retro bar in Back to the Future II.

Don’t Forget Your Mints When Using This Synthesizer

While synthesizers in the music world are incredibly common, they’re not all keyboard-based instruments as you might be imagining. Especially if you’re trying to get a specific feel or sound from a synthesizer in order to mimic a real instrument, there might be a better style synth that you can use. One of these types is the breath controller, a synthesizer specifically built to mimic the sound of wind instruments using the actual breath from a physical person. Available breath controllers can be pricey, though, so [Andrey] built his own.

To build the synthesizer, [Andrey] used a melodica hose and mouthpiece connected to a pressure sensor. He then built a condenser circuit on a custom Arduino shield and plugged it all into an Arduino Mega (although he notes that this is a bit of overkill). From there, the Arduino needed to be programmed to act as a MIDI device and to interact with the pressure sensor, and he was well on his way to a wind instrument synthesizer.

The beauty of synthesizers is not just in their ability to match the look and sound of existing instruments but to do things beyond the realm of traditional instruments as well, sometimes for a greatly reduced price point.

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Stomping On Microcontrollers: Arduino Mega Guitar Effects Pedal

Effects pedals: for some an object of overwhelming addiction, but for many, an opportunity to hack. Anyone who plays guitar (or buys presents for someone who does) knows of the infinite choice of pedals available. There are so many pedals because nailing the tone you hear in your head is an addictive quest, an itch that must be scratched. Rising to meet this challenge are a generation of programmable pedals that can tweak effects in clever ways.

With this in mind, [ElectroSmash] are back at it with another open source offering: the pedalSHIELD MEGA. Aimed at musicians and hackers who want to learn more about audio, DSP and programming, this is an open-hardware/open-software shield for the Arduino MEGA which transforms it into an effects pedal.

The hardware consists of an analog input stage which amplifies and filters the incoming signal before passing it to the Arduino, as well as an output stage which does the DAC-ing from the Arduino’s PWM outputs, and some more filtering/amplifying. Two 8-bit PWM outputs are used simultaneously to make pseudo 16-bit resolution — a technique you can read more about in their handy forum guide.

The list of effects currently implemented covers all the basics you’d expect, and provides a good starting point for writing custom effects. Perhaps a library for some of the commonly used config/operations would be useful? Naturally, there are some computational constraints when using an Arduino for DSP, though it’s up to you whether this is a frustrating fact, or an opportunity to write some nicely optimised code.

[ElectroSmash] don’t just do pedals either: here’s their open source guitar amp.

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A Bluetooth Speaker For Babies

[Mike Clifford] of [Modustrial Maker] had not one, not two, but five friends call him to announce that their first children were on the way, and he was inspired to build them a Bluetooth speaker with a unique LED matrix display as a fitting gift. Meant to not only entertain guests, but to audio-visually stimulate each of their children to promote neurological development.

Picking up and planing down rough maple planks, [Clifford] built a mitered box to house the components before applying wood finish. The brain inside the box is an Arduino Mega — or a suitable clone — controlling a Dayton Bluetooth audio and 2x15W amp board. In addition to the 19.7V power supply, there’s a step down converter for the Mega, and a mic to make the LED matrix sound-reactive. The LED matrix is on a moveable baffle to adjust the distance between it and a semi-transparent acrylic light diffuser. This shifts the light between sharp points or a softer, blended look — perfect for the scrolling Matrix text and fireplace effects! Check it out!

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Raiders Of The Lost OS: Reclaiming A Piece Of Polish IT History

In today’s digital era, we almost take for granted that all our information is saved and backed up, be it on our local drives or in the cloud — whether automatically, manually, or via some other service.  For information from decades past, that isn’t always the case, and recovery can be a dicey process.  Despite the tricky challenges, the team at [Museo dell’Informatica Funzionante] and [mera400.pl], as well as researchers and scientists from various museums, institutions, and more all came together in the attempt to recover the Polish CROOK operating system believed to be stored on five magnetic tapes.

MEERA-400 Tape Recovery 1

Originally stored at the Warsaw Museum of Technology, the tapes were ideally preserved, but — despite some preliminary test prep — the museum’s tape reader kept hanging at the 800 BPI NRZI encoded header, even though the rest of the tape was 1600 BPI phase encoding. Some head scratching later, the team decided to crack open their Qualstar 1052 tape reader and attempt to read the data directly off the circuits themselves!!

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