Retrofitting an FM radio with Arduino

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Instead of throwing out a defunct radio, this hacker decided to have some fun with an Arduino. 

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10 years ago, Marcus Jenkins purchased an inexpensive Sunstec RP-S500 FM radio. Left with an obsolete, malfunctioning device, the hacker decided to take its inner workings and convert them into an Arduino FM radio.

The radio, which appeared to be something straight out of 1975 and not 2005, was pretty bad at tuning. Aside from that, the Sunstec RP-S500 had some trouble finding stations and keeping it on without drifting off. After taking one look at its mains, and it was obvious that it was not the most well-engineered machine ever made. Meaning, any effort in trying to fix it would be useless.

Instead, Jenkins decided to have some fun with an Arduino and retrofit the gadget. His primary goals? To make it work more like an old-school car radio, hold on to a set frequency and be loud enough to hear around the workshop. Channeling his inner DIY spirit, he drew up a simple schematic that employed an Arduino Nano (ATmega328), a TEA5767 FM module and an LM386 audio amplifier.

The Arduino is connected to a microswitch with 1k pull-down and the FM radio via I2C. Meanwhile, a single button on the board helps cycle through a range of preset frequencies stored in memory. The TEA5767 module, tasked with outputting the audio, was attached to the radio’s existing antenna, an Arduino and the audio amplifier.

“The LM386 circuit is pretty standard – I had a 10u gain setting cap and a 10k pot on the input for setting the radio volume to ‘loud but not distorted.’ The 9V and 5V rails are decoupled with electrolytics and smaller mylars,” Jenkins writes.

He kept the Sunstec RP-S500’s original tuning knob, though no longer functional, and fitted the old AM/FM selector with a microswitch linked to the Arduino. This would enable him to switch between preset channels. Everything was held together with what Jenkins calls “hot-snot glue.”

Impressively, the entire project only cost the Maker $1.50, as everything was recycled from items lying around. Interested? Head over to its detailed post here.

Oro is an SMS alarm temperature watchdog

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Need to leave your pup in the car? This Arduino-powered device will send you a text if it gets too warm inside.

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Maker Richard Deininger has developed an SMS alarm temperature watchdog. The idea for Oro was first conceived as a simple alert system for whenever the AC system in his company’s server room went down. Upon showing it off to his colleagues, the dog-loving bunch informed him that the DIY gadget would also make for an excellent tool to ensure that the inside of a car never got too hot for poor Fido.

Now an entry in this year’s Hackaday Prize, the dog owner application itself is pretty straightforward. It is comprised on an Arduino Uno (ATmega328), a DHT22 temperature and humidity probe, a 2000uF capacitor, a power bank with two outputs, and a SIM900 GSM modem — all housed inside a small enclosure for optimum portability.

An owner defines a temperature threshold to get started, and should the thermometer escalate to unsafe levels for the pup, they will be notified via text message.

Interested? Head over to the project’s Hackaday.io page here.

Turning an old-school typewriter into a printer

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Maker transforms his 1960s Smith Corona electric typewriter into a percussive printer.

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One thing that continues to amaze us about the Maker Movement is the ingenuity of DIYers in how they upcycle antiquated devices, from floppy drives to old phones to typewriters. Just when we thought we’ve seen it all, Tufts University computer engineer Chris Gregg decided he wanted to transform his vintage 1960s Smith Corona electric typewriter into a printer that could be controlled by his PC.

Gregg had initially hoped to find a way to drive the key switches without actually having to touch the keys of the typewriter, but quickly learned that this was impossible as the switches were not electronic. The machine was instead activated by a complex mechanical system, not to mention was so meticulously constructed that there was virtually no way to interface anything inside of it. Upon coming to this realization, the Maker put the project on the shelf before finally coming back to it several years later.

“Flash forward to winter 2015. I was sitting with my colleague at Tufts University, Bruce Molay, and I mentioned to him my failed idea, but he encouraged me to give it another shot. So, I brought the typewriter into work the next day, and Bruce took one look at it and said, ‘solenoids.’ This was the answer, although not really the one I wanted to hear,” Gregg explains.

With this newfound plan of activating the keys with the solenoids controlled by his computer, the project continued onward with a little help from his fellow colleagues. The solenoids were then mounted to a laser-cut, two-layer acrylic holder. Meanwhile, the system employed a TPIC6A595 shift register capable of handling up to 50V — which meant the Maker only needed to use one Arduino pin to provide an input value and a few more pins for shift register control.

After debating between a Raspberry Pi, Arduino or a LightBlue Bean to serve as the brains of the operation, Gregg finally selected an Uno (ATmega328). The Arduino converts input over USB to a bit stream that can be used by the shift registers, which is fed data through an OS application, while a custom CUPS driver enables the MacBook to print documents using the typewriter.

“It has been a bit wonky so far, but I’ve proved the concept and need to debug it some more,” the Maker says in reference to the CUPS driver. “Bruce wants to write a graphics-to-ASCII art translator so we can print any document, but I fear that may tax the poor Smith Corona a bit much.”

To best demonstrate the project, Gregg naturally chose to have it play percussion for Leroy Anderson’s “The Typewriter Symphony.” Trust us, you’ll want to see it in action below!

Grow veggies in your garden with this countertop hack

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This Hackaday Prize entrant converted his Koolatron wine cooler into an Arduino-controlled kitchen garden.

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Having long enjoyed growing his own food, Eric William had been on the lookout for a commercial indoor unit that would enable him to grow vegetables, herbs and sprouts year round. Turns out, most products on the market significantly lacked the necessary climate control, lighting and proprietary seed pods that the Canadian Maker had been seeking.

Unhappy with the products on the market today, William decided to take matters into his own hands. So in true DIY fashion, the Maker converted a conventional Koolatron wine fridge into an Urban Kitchen Garden using an Arduino Nano (ATmega328). The project, which is an entry in this year’s Hackaday Prize, is designed to control the temperature, humidity and soil moisture for a wide range of micro-greens, including basil as seen in his video below. A simple 12V LED spotlight was hacked for the lighting element, while a Nokia 5110 LCD was tasked with displaying its parameters.

William also added a real-time clock module to monitor the time of day as well as a fan to the machine. However the Maker notes that, in future iterations, he is hoping to ventilate the unit so that the heat can escape from inside the chamber. Aside from that, its unique setup allows for additional components, such as a peristaltic pump for automated watering based on the plant’s soil moisture, should he choose to include them.

Looking for a countertop garden of your own? Head over to the Maker’s Hackaday.io page here. In the meantime, see it in action below!

Panda is a 3D-printed, Arduino-powered cleaning robot

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This Maker’s mini cleaning machine that is like a Roomba on steroids. 

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As our world continues to get smarter, it seems like many of us are becoming increasingly less fixated on taking care of our homes and more on our homes taking care of us. While we await a Rosie The Maid-like robot sidekick that can take care of the mundane tasks around the house, from folding our clothes to washing the dishes, Maker Jake Lee has took a stab at creating a DIY cleaning machine that can do a little bit more than the typical Roomba.

The Panda, named after his soon-to-be-born son’s nickname, is a robotic device that boasts a number of enhanced features like air suction, a sweeper and a roller brush. Lee had originally devised a project two years ago, however found it to be a bit too small and that it had to be connected to a power source, like a PC, with the cable dangling in the air. As you can imagine, that’s not the most convenient set up for a freely moving machine.

Back with his second iteration, the new design is a little larger, measuring in at around 6” x 6” and is capable of sweeping and vacuuming not just the floor but his desk as well. The mini robot chooses its directions randomly, and can even detect cliffs or other obstacles that may stand its way.

The top, bottom and mid-housing components, along with its two battery covers, gear box and dust cabinet were all 3D printed on Lee’s MakerBot Replicator 2X. As for its hardware, Panda is based on an Arduino Uno (ATmega328) and runs on a pair of 135 RPM gear motors for the wheels, a 1000RPM motor for the roller and sweeper, as well as a DC 3V motor for the vacuum and fan blade. Beyond that, Lee used PRO_E modeling software, but notes that just about any program would suffice.

To reinforce the suction capabilities form his earlier model, the Maker added a roller with brushes and a sweeper. Perhaps one of the more challenging steps of the project was determining a way to use the gears rather than a motor to power the roller and sweeper, since it would consume less battery power. According to Lee, not only does this setup save battery power, it also works like a charm.

Looking for a robotic cleaning gadget of your own? Check out Lee’s detailed Instructables page here to get started.

Building an arcade-style puzzle game with Arduino

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Games are great and all, but who among us needs another screen in their life?  

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Many of us, like Grady Hillhouse, have a deep-seated desire to push every button, flip every switch and turn every knob that we see. As kids, that impulse undoubtedly drove our parents nuts. After learning about and tinkering around with some electronics, the Maker — who happens to also be a civil engineer by trade — was on a mission to create an interactive project. One of the ideas that first came to mind was to create an old-school, arcade-style puzzle box that resembled the ubiquitous wooden audio equipment of the ‘70s.

Rather than use the original plastic enclosure that he purchased, the Maker fully committed to go the do-it-yourself route. This include honing his woodworking skills. The custom box is comprised of a few walnut panels and knobs as well as maple veneer meter faces. Based on an Arduino Uno (ATmega328), the unit is equipped with 10 LEDs, three potentiometers, two panel meters, a button and a vibration motor.

To start the game, one random LED will light in each of the meters. From there, the objective is to adjust the three knobs so that each needle points to its respective LED at the same time. However, it’s not as easy as it sounds. Each of the knobs have a unique and random releationship to the meters, so players will have to experiment a bit to discover how to make the needles move to the right location. When the puzzle is solved, the vibration motor buzzes and it resets to a new configuration.

For those out there who like to crunch numbers, the game even has a mathematical element to it. The goal is to find the intersection between two three-dimensional planes. Intrigued? You can watch Hillhouse’s elaborate video tutorial below, or head over to his GitHub repository here to get started on a wooden arcade box of your own.

The Fibonacci Clock requires you to do math to tell the time

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This open source clock is for nerds with style, and even doubles as a lava lamp.

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Over the past couple of years, various iterations of modern-day timepieces have emerged on Kickstarter. While Makers have come up with just about everything from nixie and binary to projection and word clocks, none of them have ever required a little math in order to tell the time. That was up until now.

As for what may very well be the nerdiest clock of all-time, Canadian software developer Philippe Chrétien has devised a gadget that uses the Fibonnaci Sequence to reveal the time. For those unfamiliar with the sequence created by the Italian mathematician Leonardo Fibonacci back in the 13th century, the pattern begins with 1 and 1, and each subsequent number is the sum of the previous two. 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, etc. For this device, the Maker only used the first five terms: 1, 1, 2, 3 and 5.

The screen of the aptly named Fibonacci Clock is comprised of five colorful squares, whose side lengths match the first five sequential numbers (1, 1, 2, 3 and 5) and are backlit with LEDs. Red illuminations are used to denote the hours, while green for the minutes. When a square is tasked with displaying both the hours and minutes, it emits blue. All of the white squares are there for decorative purposes and can be ignored.

Unlike its digital counterparts, which simply require you to glance over at the time, this clever piece calls for you to hone your arithmetic skills along with some color-changing effects. To read the hour, add up the corresponding values of the red and blue squares. To read the minutes, do the same with the green and blue squares. The minutes are shown in five minute increments (0 to 12) so you have to multiply your result by five to get the actual number.

For instance, take the time of 9:25. 9:00 would be indicated by a red 5, a red 1 and a blue 3, in other words 5 + 1 + 3 = 9. Meanwhile,  the 0:25 would then be made up of green 2 and blue 3, or 2 + 3 = 5. 5 x 5 = 25 minutes. Confused? Let’s just hope your brain likes a little challenge in the morning. Turns out, there are actually multiple ways to display a single time as well.

“To add to the challenge, the combinations are picked randomly from all the different ways a number can be displayed. There are, for example, 16 different ways to display 6:30 and you never know which one the clock will use,” the Maker writes.

Chrétien says the clock is ideal for “curious and inventive people who like a timepiece that keeps them on their toes.” And there seems to be plenty of them out there, as the gadget attracted more than 1,240 backers during its Kickstarter run.

What’s more, the Fibonacci Clock can also be transformed into a lava-like lamp by pressing the mode button on its back. Two different lamp modes are included, yet in true open source fashion, users can hack the clock to make it their own. That’s because the innovative accessory is driven by an ATmega328P, which means its code can be modified using the Arduino IDE. The electronics are all housed inside an aesthetically-pleasing wooden case.

“The possibilities are as infinite as the Fibonacci sequence! I can’t wait to see what you will come up with,” Chrétien writes.

Following its incredibly successful crowdfunding campaign — which garnered over $181,000 — assembly is underway with shipments expected to begin this fall. Sound like a gadget you’d love to have? Pre-order yours today.

This LEGO Super Mario Bros. sprite plays polyphonic music

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Maker creates an electronic LEGO Super Mario Bros. Dry Bones sprite with glowing eyes and polyphonic music.

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Who could forget the days of slipping a Super Mario Bros. cartridge into their Nintendo console and the distinct chiptune soundbites that ensued from hitting every power-up? Inspired by the ‘80s pop culture phenomenon, last year Baron von Brunk created mini 3D pixelated versions of the iconic Starman and Super Mushroom boosters entirely from LEGO pieces, and impressively, embedded them with circuitry to emit sound and flash LED lights in unison.

Now several months later, the Maker has returned with another slick project — which he tweeted to us just moments ago. Using similar technology as his previous LEGO Super Mario power-ups, he has designed a new 3D sprite that can actually play polyphonic music. This is made possible through Len Shustek’s Miditones Arduino code, which is capable of converting MIDI files into binary code and then being split amongst multiple AVR timers for three sound channels.

For this particular build, von Brunk chose the Fortress theme from Super Mario Bros. 3. Along with the tunes, the eyes once again blink with a flickering red LED. However, unlike his previous projects, the Dry Bones model employs four AAA batteries along with an ATmega328P, rather than two coin cells and an ATtiny85.

“I wanted to use a standard LED to blink in synch with the music, but alas I wasn’t able to achieve this due to the ATmega’s timers being occupied with the musical score,” the Maker explains.

Intrigued? See it in action below!

This three-axis motion sensor gyroscope is based on an Arduino Pro Mini

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Maker Martin Cote has developed a three-axis motion sensor gyroscope that enables you to track head or arm movement, then reproduce it on servos. 

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Initially conceived for head-tracking FPV goggles, Martin Cote has created a three-axis motion sensor gyroscope based on an Arduino Pro Mini (ATmega328). Applicable in a wide range of settings, users can track the movement of the head or arm, and replicate it on a set of servos.

Available in two different versions, both wired (Iota) and wireless (Z-ita), the gyroscope is ideal for Makers seeking an inexpensive head-tracking system yet are not comfortable with the advanced programming of accelerometers. Sample use cases include robotics, remote-controlled toys, gaming and interfacing with computers.

First, Iota provides users with the ability to control mini servos that reproduce movement on three axes, as well as reverse the direction of the servos to act as a stabilizer. Measuring just 1” x 3″ in size, the super small and lightweight unit can be easily integrated into any project. Meanwhile, Z-ita does pretty much the same thing but wirelessly within a range of 30 to 50. This set comes with the Ita receiver, which transmits the signals to the servos, as well as a battery capable of lasting of over two hours. What’s more, it offers a selection of 16 channels at the frequency of 2.4Ghz, and allows more than one to be used at a time.

“You want to use the accelerometer signals to another type of application? Get the Iota or Z-ita set and plug it into your Arduino MCU according to the video and use the sketch file provided (which you can adapt to your needs), and look for new possibilities to suit your needs.”

Interested? Head over to Kickstarter page, where Cote has already well exceeded his initial goal of $408. Shipment is expected to begin in October 2015. 

Rigging the dashboard of an actual car for a driving simulator game

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Instead of buying or building a console, one Maker decided to use the dashboard of an actual car for his ETS2 game.

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Like countless other gamers out there, Leon Bataille has always been on the lookout for new ways to make driving simulator games like Euro Truck Simulator 2 (ETS 2) even more immersive. And though homemade steering wheels, pedals and gear shifters certainly enhance the levels of interaction, what better way to really enhance the life-like experience than by integrating the game with a dashboard from a real automobile?

Doing just that, Bataille repurposed the control panel of a VW Polo 6R with the help of the Arduino Uno (ATmega328) and a Seeed CAN Bus Shield, which enabled him to read and record vehicle diagnostics. This project was originally inspired by fellow Maker Silas Parker’s Arduino-driven control panel that was comprised of a cardboard box, servos, LEDs and an LCD screen. Though it was completely functional, knowing that every unit made in the past decade has a CAN bus, all he would need to bring his idea to life was a CAN bus shield for an Arduino along with a dash that could be found at any local junkyard.

Currently, Bataille is in the process of figuring out the CAN bus addresses for each of the relevant dials and LEDs on the dashboard. Though he may still have a little ways to go, he has been able to find the tachometer at 0x280, the signal lights at 0x470, as well as the KPH gauge at 0x5A0. Pair this with a standard computer steering wheel and the telemetry API for ETS 2, and the Maker is pretty darn close to driving a virtual big rig right from the comforts of his own home.

Until then, you can follow along with his build on Hackaday here, and watch it in action below.