Personal Compass Points To Your Spawn Point

November 5, 2016 by Al Williams 22 Comments

A conventional compass points north (well, to magnetic north, anyway). [Videoschmideo] wanted to make a compass that pointed somewhere specific. In particular, the compass — a wedding gift — was to point to a park where the newlywed couple got engaged. Like waking up in a fresh new Minecraft world, this is their spawn point and now they can always find their way back from the wilderness.

The device uses an Arduino, a GPS module, a compass, and a servo motor. Being a wedding gift, it also needs to meet certain aesthetic sensibilities. The device is in an attractive wooden box and uses stylish brass gears. The gears allow the servo motor to turn more than 360 degrees (and the software limits the rotation to 360 degrees). You can see a video of the device in operation, below.

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Minimal Arduino Clock

November 2, 2016 by Al Williams 19 Comments

Making a clock with a common microcontroller like an Arduino isn’t very difficult. However, if you’ve tried it, you probably discovered that keeping track of wall time is difficult without some external hardware. [Barzok] has a very minimal clock build. It takes a handful of LED arrays with an integrated driver, an Arduino Nano, a real-time clock module, and a voltage regulator.

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Rotary Cell Phone: Blast From A Past That Never Was

November 2, 2016 by Dan Maloney 32 Comments

The 1970s called and they want their rotary dial cell phone back.

Looking for all the world like something assembled from the Radio Shack parts department – remember when Radio Shack sold parts? – [Mr_Volt]’s build is a celebration of the look and feel of a hobbyist build from way back when. Looking a little like a homebrew DynaTAC 8000X, the brushed aluminum and 3D-printed ABS case sports an unusual front panel feature – a working rotary dial. Smaller than even the Trimline phone’s rotating finger stop dial and best operated with a stylus, the dial translates rotary action to DTMF tones for the Feather FONA board inside. Far from a one-trick pony, the phone sports memory dialing, SMS messaging, and even an FM receiver. But most impressive and mysterious is the dial mechanism, visible through a window in the wood-grain back. Did [Mr_Volt] fabricate those gears and the governor? We’d love to hear the backstory on that.

This isn’t the first rotary cell phone hybrid we’ve featured, of course. There was this GSM addition to an old rotary phone and this cell phone that lets you slam the receiver down. But for our money a rotary dial cell phone built from the ground up wins the retro cool prize of the bunch.

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What’s New, ESP-32? Testing The Arduino Library

October 31, 2016 by Elliot Williams 30 Comments

In case you missed it, the big news is that a minimal Arduino core is up and working on the ESP32. There’s still lots left to do, but the core functionality — GPIO, UART, SPI, I2C, and WiFi — are all up and ready to be tested out. Installing the library is as easy as checking out the code from GitHub into your Arduino install, so that’s exactly what I did.

I then spent a couple days playing around with it. It’s a work in progress, but it’s getting to the point of being useful, and the codebase itself contains some hidden gems. Come on along and take a sneak peek.

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Litter Basket Automation

October 30, 2016 by Al Williams 9 Comments

Sometimes the technology part of a project isn’t the hard part. It is having an idea for something both useful and doable. Sure, a robot butler that would do your cleaning and laundry would be useful, but might be out of reach for most of us. On the other hand, there’s only so many use cases for another blinking LED.

[Martinhui] knows how to use an ultrasonic sensor with an Arduino. Driving a motor isn’t that hard, either. The question is: what do you do with that? [Martin’s] answer: Automate a trash can. You can see a video of the result, below.

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Primer On Servos Hits All The Basics

October 30, 2016 by Dan Maloney 10 Comments

Servos are pretty basic fare for the seasoned hacker. But everyone has to start somewhere, and there’s sure to be someone who’ll benefit from this primer on servo internals. Who knows – maybe even the old hands will pick up something from a fresh perspective.

[GreatScott!] has been building a comprehensive library of basic electronics videos over the last few years that covers everything from using a multimeter to programming an Arduino. The last two installments delve into the electromechanical realm with a treatment of stepper motors along with the servo video below. He covers the essentials of the modern RC-type servo in a clear and engaging style that makes it easy for the newbie to understand how a PWM signal can translate into positional changes over a 180° sweep. He shows how to control a servo directly with an Arduino, with bonus points for including a simple 555-based controller circuit too. A quick look at the mods needed to convert any servo to continuous rotation wraps up the video.

If [GreatScott!]’s video whets your appetite for more, be sure to check out [Richard Baguley]’s deeper dive into servos. And when you’re ready to put your new-found knowledge into practice, maybe a nice project would be to convert a hobby servo into a linear actuator.

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Dual-boot Your Arduino

October 25, 2016 by Elliot Williams 28 Comments

There was a time, not so long ago, when all the cool kids were dual-booting their computers: one side running Linux for hacking and another running Windows for gaming. We know, we were there. But why the heck would you ever want to dual-boot an Arduino? We’re still scratching our heads about the application, but we know a cool hack when we see one; [Vinod] soldered the tiny surface-mount EEPROM on top of the already small AVR chip! (Check the video below.)

Aside from tiny-soldering skills, [Vinod] wrote his own custom bootloader for the AVR-based Arduino. With just enough memory to back up the AVR’s flash, the bootloader can shuffle the existing program out to the EEPROM while flashing the new program in. For more details, read the source.

While you might think that writing a bootloader is deep juju (it can be), [Vinod]’s simple bootloader application is written in C, using a style that should be familiar to anyone who has done work with an Arduino. It could certainly be optimized for size, but probably not for readability (and tweakability).

Why would you ever want to dual boot an Arduino? Maybe to be able to run testing and stable code on the same device? You could do the same thing over WiFi with an ESP8266. But maybe you don’t have WiFi available? Whatever, we like the hack and ‘because you can’ is a good enough excuse for us. If you do have a use in mind, post up in the comments!

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