Primary image

[Please excuse my English]

read more

Primary image

[Please excuse my English]

read more

Primary image

[Please excuse my English]

read more

Space. The final frontier. Unfortunately, the vast majority of us are planet-locked until further notice. If you are dedicated hobbyist astronomer, you probably already have the rough positions of the planets memorized. But what if you want to know them exactly from the comfort of your room and educate yourself at the same time? [Shubham Paul] has gone the extra parsec to build a Real-Time Planet Tracker that calculates their locations using Kepler’s Laws with exacting precision.

An Arduino Mega provides the brains, while 3.5-turn-pan and 180-degree-tilt servos are the brawn. A potentiometer and switch allow for for planet and mode selection, while a GPS module and an optional MPU9250 gyroscope/magnetometer let it know where you are. Finally a laser pointer shows the planet’s location in a closed room. And then there’s code: a lot of code.

The hardware side of things — as [Shubham Paul] clarifies — looks a little unfinished because the focus of the project is the software with the intent to instruct. They have included all the code they wrote for the RTPT, providing a breakdown in each section for those who are looking to build their own.

There is an extra step to auto-align the RTPT to north, otherwise you’ll have to do so manually. But [Shubham Paul] has designed it so that even if you move the tracker about, the RTPT will readjust its calculations in real time. Each part of the project includes a wealth of related information beyond simple instructions to adequately equip any prospective builders.

This hack gets the job done. If it’s looks you’re after, an artistic expression of maker skills and astronomy can be seen in this planetary map that relies on persistence of vision.

RC flying is one of those multi-disciplinary hobbies that really lets you expand your skill set. You don’t really need to know much to get started, but to get good you need to be part aeronautical engineer, part test pilot and part mechanic. But if you’re going to really go far you’ll also need to get good at electronics, which was part of the reason behind this Arduino servo tester.

[Peter Pokojny] decided to take the plunge into electronics to help him with the hobby, and he dove into the deep end. He built a servo tester and demonstrator based on an Arduino, and went the extra mile to give it a good UI and a bunch of functionality. The test program can cycle the servo under test through its full range of motion using any of a number of profiles — triangle, sine or square. The speed of the test cycle is selectable, and there’s even a mode to command the servo to a particular position manually. We’ll bet the build was quite a lesson for [Peter], and he ended up with a useful tool to boot.

Need to go even further back to basics than [Peter]? Then check out this primer on servos and this in-depth guide.

[via r/Arduino]

[Ryan Bates] loves arcade games, any arcade games. Which is why you can find claw machines, coin pushers, video games, and more on his website.

We’ve covered his work before with his Venduino project. We also really enjoyed his 3D printed arcade joystick based off the design of a commercial variant. His coin pushing machine could help some us finally live our dream of getting a big win out of the most insidious gambling machine at arcades meant for children.

Speaking of frustrating gambling machines for children, he also built his own claw machine. Nothing like enabling test mode and winning a fluffy teddy bear or an Arduino!

It’s quite a large site and there’s good content hidden in nooks and crannys, so explore. He also sells kits, but it’s well balanced against a lot of open source files if you’d like to do it yourself. If you’re wondering how he gets it all done, his energy drink review might provide a clue.

Over the last couple of years, cat videos have become the undisputed champions of the web. Whether it’s kittens playing with their shadows to failed jump attempts to giving each another massages, we’re all guilty of watching a few of these clips from time to time (yes, even at work). Built with this in mind, oCat is a real-time tracker for feline-related activity on the Internet.

oCat consists of two parts: the oCat News Distractor and the Kitty o’Cat Twitter bot. Using Google’s YouTube API, the system works by continuously monitoring for new uploads, the number of new views each day, or a specific video that has received a remarkable amount of attention. It then tweets these stats and prints them out on thermal paper, stamping a paw print on the timeline for every 1,000 views.

Created by Annika Engelhardt, a digital media design master’s student at the University of the Arts in Bremen, oCat uses an Arduino along with an ESP Wi-Fi module, a servo, and an LCD screen. The aim of the project is to increase and reveal the amount of hours people spend watching cat videos online.

The cat is an altered Maneki-neko, holding a stamp using welding wire and hot glue. Even though I filled the stamp with extra ink, it did not work properly and I had to cut out the paw-shape from a sponge and glue it onto the original stamp.

The thermal printer used in the device needs a USB connection, so I used a Raspberry Pi to control it. I wrote a Python script that checks four different RSS news feeds for new posts every 15 minutes and prints one headline with a timestamp every minute.

The Twitter bot was programmed using Python and a library called tweepy. Most of the script is reading JSON files, juggling and comparing data and text files and in the end mixing up parts of a sentence to form a tweet. The bot will be enhanced in the future

Engelhardt exhibited the project at Galerie Flut in Bremen back in October. You can find more pictures and information on the project here.

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.

[Markus Gritsch] and his son had a fun Sunday putting together a little toy airboat from a kit. They fired it up and it occurred to [Markus] that it was pretty lame. It went forward and sometimes sideward when a stray current influenced its trajectory, but it had no will of its own.

The boat was extracted from water before it could wander off and find itself lost forever. [Markus] did a mental inventory of his hacker bench and decided this was a quickly rectified design shortcoming. He applied a cheap knock-off arduino, equally cheap nRF24L01+ chip of dubious parentage, and their equivalent hobby servo to the problem.

Some quick coding later, assisted by prior work from other RC enthusiasts, the little boat was significantly upgraded. Now the boat could be brought back to shore using any R/C controller that supported the, “Bayang,” protocol. He wouldn’t have to face the future in which he’d have to explain to his son that the boat, like treacherous helium balloons, was just gone. Video after the break.

Tired of being harassed by your cat? [MomWillBeProud] made a cheap, effective — and more importantly cat-operated — cat food dispenser.

The feeder is of an efficient construction — a double cat food dish, one container to store the electronics, and a Pringles can to act as the hopper. A simple servo rotates the hopper thirty degrees and back on each button press; using gravity to drop food through an opening that appears due to this motion. The button itself is an old IKEA timer and a piece of plastic large enough for a hungry cat to swat.

An Arduino controls the servo, and while [MomWillBeProud] skips over going into detail on his code, you can check it out here.

[MomWillBeProud] toyed with the idea of scheduled feeding, but believes his cat is smart enough to feed itself; indeed — training cats is hard work, and it took a couple of weeks for the lessons to sink in. He also recommends using an Arduino Pro Mini, since it consumes so little power that it can operate for months on one set of batteries. Since [MomWillBeProud]’s cat needs a refill only once a week, that’s a lot less time fussing with one’s feline companions.

If you want a similarly hands-off method to ensure your pets have water, we previously featured a project that keeps your pet’s water bowl topped off.

[via /r/DIY]