[agp.cooper]’s son recently went to China, and the biggest complaint was the Great Firewall of China. A VPN is a viable option to get around the Great Firewall of China, but [agp] had a better idea: an acoustic coupler for his son’s iPhone.

Hackaday readers of a recent vintage might remember an old US Robotics modem that plugged into your computer and phone line, allowing you to access MySpace or Geocities. Yes, if someone picked up the phone, your connection would drop. Those of us with just a little more experience under our belts will remember the acoustic coupler modem — a cradle that held a phone handset that connected your computer (indirectly) to the phone line.

With a little bit of CNC work, [agp] quickly routed out a block of plywood that cradled his son’s iPhone. Add in a speaker and a microphone, and that’s an acoustic coupler. There’s not much to it, really. The real challenge is building a modem.

In the late 90s, there were dedicated chipsets for modems, and before that, there was a 74xx-series chip that was a 300-baud modem. [agp] isn’t using anything like that. He’s building a modem with an Arduino. This is a Bell 103A-compatible modem, allowing an iPhone to talk to a remote computer at 300 bits per second. This is a difficult challenge; we’re not able to get 33kbps over a smartphone voice connection simply because of the codecs used. However, with a little bit of work, [agp] managed to build a real modem with an Arduino.

Clocks that read time via received radio signals have several advantages over their Internet-connected, NTP-synchronised brethren. The radio signal is ubiquitous and available over a fairly large footprint extending to thousands of kilometres from the transmitting antennae. This allows such clocks to work reliably in areas where there is no Internet service. And compared to GPS clocks, their front-end electronics and antenna requirements are much simpler. [Erik de Ruiter]’s DCF77 Analyzer/Clock is synchronised to the German DCF77 radio signal, which is derived from the atomic clocks at PTB headquarters. It features a ton of bells and whistles, while still being simple to build. It’s a slick piece of German hacker engineering that leaves us amazed.

Among the clock functions, it shows time, day of the week, date, CET/CEST modes, leap year indications and week numbers. The last is not part of the DCF77 protocol but is calculated via software. The DCF77 analyzer part has all of the useful information gleaned from the radio signals. There are displays for time period, pulse width, a bit counter, bit value indicator (0/1) and an error counter. There are two rings of 59 LEDs each that provide additional information about the DCF77 signal. A PIR sensor on the front panel helps put the clock in power save mode. Finally, there is a whole bunch of indicator LEDs and a bank of switches to control the various functions. On the rear panel, there are RJ45 sockets for the DCF77 receiver antenna board, temperature sensor and FTDI serial, a bunch of audio sound board controls, reset switches and a mode control switch.

His build starts with the design and layout of the enclosure. The front panel layout had to go through a couple of iterations before he was satisfied with the result. The final version was made from aluminium-coated sandwich-panel. He used an online service to photo-etch the markings, and then a milling machine to carve out the various windows and mounting holes. The rear panel is a tinted acrylic with laser engraving, which makes the neatly laid out innards visible for viewers to appreciate. The wooden frame is made from 40-year-old Mahogany, sourced from an old family heirloom desk. All of this hard work results in a really professional looking product.

The electronics are mostly off the shelf modules, except for the custom built LED driver boards. The heart of the device is an Arduino Mega because of the large number of outputs it provides. There are seven LED driver boards based around the Maxim 7221 (PDF) serial interface LED drivers – two to drive the inner and outer ring LEDs, and the others for the various seven-segment displays. The numerous annunciator LEDs are driven directly from the Arduino Mega. His build really comes together by incorporating a noise resilient DCF77 decoder library by [Udo Klein] which is running on a separate Arduino Uno. All of his design source files are posted on his GitHub repository and he hopes to publish an Instructable soon for those who would like to build one of their own.

In the first video below, he walks through the various functions of the clock, and in the second one, gives us a peek in to its inside. Watch, and be amazed.

Thanks for the tip, [Nick]

Silencing a smartphone at night isn’t difficult, but if you have a landline, Arduino can help!

Before computer hacking/modding became accessible, the next best thing was to creatively explore the phone system via custom electronics. Though this pursuit, known as “phone phreaking,” has largely gone away, some people still have landlines. As “MolecularD” shows in this Instructables writeup, with a few components you can creatively trick your phone into not ringing on your end, while appearing to the caller to simply ring and ring as if no one is home.

In order to make it much more useful, MolecularD hooked up an Arduino Mega with a real-time clock module to turn the device on and off depending on the time of day. Now calls from phone solicitors, or “IRS agents” at 4 in the morning can be eliminated automatically. As noted, this may or may not be legal where you live, so attempt it at your own risk!

Meet Cynthia Cho

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As touched on in this video by Charlotte Dann (aka “Charbytes”), she has magnets in her fingers.

This may or may not seem like a small detail, but either way it allows her to draw interesting shapes by passing them over a magnetometer mounted to an Arduino Uno. Dann’s sensor/Arduino package passes serial data to a computer, which does the “heavy lifting,” turning the input into beautiful colors on a computer screen.

It’s an interesting project, and the build process is nicely narrated in her video. A few highlights include a problem with “plastic weld” at 4:00, and a few electrical issues around 7:30 that she eventually solves. You can see more details on this project on its GitHub page, as well as check out Dann’s Twitter account to see what else she’s up to!

After procuring a new Easy-Bake Oven, engineer Jason Cerundolo decided to convert it to run off of USB. According to his project write-up, “USB-C spec allows for 100 Watts of power to be transferred through the connector, and that is the power rating for the oven, so it should work.”

The biggest modification in this build was dividing the heating element into six segments in order to power it with 20V allowed over USB-C. Finding a suitable charger for this device was also a bit of a challenge, but after 20 minutes, it was able to reach 300° F, producing five strangely-shaped but likely still tasty cookies!

For the electronics, I used my USB-C breakout board with the FUSB302B PHY and an Arduino Uno. I wired I2C plus interrupt between the two. I connected VBUS from the breakout board to VIN on the Arduino to power it. Then, I connected +3V3 from the Arduino to the VDD on the breakout board to power the FUSB302B, as well as +5V to V_pullup on the breakout board. I also connected VBUS to the switch, then to the modified heating element and back to GND. To make the connections easier, I crimped spade connectors onto jumper wires. Finally, I plugged the modified light into pin 13 on the Arduino.

You can check out more about Cerundolo’s project, and find his code on GitHub.

We so often hack for hacking’s sake, undertaking projects as a solitary pursuit simply for the challenge. So it’s nice to see hacking skills going to good use and helping someone out. Such was the case with this low-cost two-axis handheld camera gimbal intended to help a budding photographer with a motion disorder.

When [Tadej Strah] joined his school photography club, a fellow member who happens to have cerebral palsy needed help steadying cameras for clean shots. So rather than shell out a lot of money for a commercial gimbal, [Tadej] decided to build one for his friend. A few scraps of aluminum bar stock were bent into the gimbal frames and camera mount. Two hobby servos take care of the pitch and roll axes, controlled by an Arduino talking to an MPU-6050. Mounted to a handle from an angle grinder with the battery and electronics mounted below, the gimbal looks well-balanced and does a good job of keeping the camera level.

Hats off to [Tadej] for pitching in and solving a real world problem with his skills. We like to see people helping others directly, whether it’s building a gyroscopic spoon for Parkinson’s sufferers or vision enhancement for a nearly blind adventurer.

[via r/arduino]

John Edgar Park builds a giant 7-segment display timer for a Ninja obstacle course.

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The post Who on Earth Needs a Ninja Timer? appeared first on Make: DIY Projects and Ideas for Makers.

Electronic interfaces have advanced from plugging things in, to keyboards, touchscreens, VR environments, and perhaps soon temporary tattoos. Led by Martin Weigel, researchers at Saarland University in Saarbrücken, Germany have come up with a way to turn your skin blemishes and wrinkles into touch-sensitive controls for devices like smartphones and computers.

“SkinMarks” can be transferred onto the skin using water and last a couple of days before rubbing off. As seen in the video below, these e-tattoos can take the form of buttons, sliders and visual displays, and even sense when a joint is bent. For example, knuckles on a hand made into a fist could act as buttons and then become a slider when the fingers are straightened.

Another type of SkinMark is electroluminescent, meaning that an image printed on your skin could light up to signal a phone call or other important notifications. These tattoos are connected to a wrist-mounted Arduino Nano and an Adafruit MPR121 capacitive touch shield via wires and copper tape; though if the system can be shrunk down even further, this could open up many different possibilities!

You can find more information on this project on New Scientist, or in the team’s published paper here.

[Absolutelyautomation] has a problem with seven-segment displays. Fitting these displays in an enclosure is a pain because you can’t drill perfectly square holes, and you will invariably mess up a few enclosures with overzealous file work. There is a solution to this problem – panel mount meters.

The bezels on these panel mount meters hide the imperfections in the enclosure, and usually don’t require screws. They are, however, dedicated displays, usually for temperature, RPM, or some other measurement.

[Absolutelyautomation] took one of these dedicated panel mount displays and turned it into an all-purpose device. Basically, it’s a panel mount Arduino with three seven-segment displays.

This project is built on perfboard cut down to fit inside the enclosure of a very cheap panel meter found at the usual suppliers. Tucked away underneath this perfboard is an ATmega, a few resistors, and the support parts to make everything go. This panel mount meter can either be a serial slave or as a standalone controller, programmable with the Arduino IDE. It’s cheap, too. You can check out [Absolutelyautomaion]’s video below.