Planet Arduino

How do we know that planets exist outside of our solar system? While too far away to observe directly, with extremely sensitive equipment like the Kepler space telescope it’s possible to detect changes in light as these exoplanets pass in front of a star. For an excellent visualization of how this all works, check out Marcin Poblock’s simplified model in the video below.

The 3D-printed apparatus employs an Arduino Nano that controls the motion of two planets around a light bulb “star,” via a stepper motor and gear system. The variable light is then sensed by an LDR on a separate Nano-driven device. This sends info to a computer over serial to be graphed in real-time, and can also store it on an SD card for later analysis. 

While this project won’t necessarily help you explore our galaxy, it will provide you with a fun way to learn about the principle of exoplanet detection using the transit method.

The South Florida Science Center recently added a new ten-inch telescope and turned to [Andres Paris] and his brother to replace the hand-cranked dome door system. They turned to an Arduino along with some beefy motor drivers. You can see some videos of the beast in operation, below.

According to a Reddit post, the brothers picked up a 5A 12V motor but decided to overdesign and selected an H-bridge that would handle 20A peak current. An IR remote allows the operator to open and shut the door and reed switches sense the extremes of the door’s motion.

The second video shows the motor and the 3D printed coupling to the existing door gear train. Since the displays on the box are fairly bright, the operator can turn them off using the remote control.

It doesn’t look as thoug any code or diagrams are available, but we are guessing that this type of system would be custom for each individual case anyway. As it turned out, the moving of the existing gear train wasn’t the biggest problem, instead it was supplying the power.

Since the dome rotates, it was not possible to wire the box to power. The system uses some batteries that right now have to be manually charged. However, the brothers plan to take advantage of the fact that the dome is always put back to the same position so they can wirelessly charge the batteries using a Qi transmitter that lines up with the associated receiver when in the home position.

If you would like your own dome, we — along with the Wayback Machine — can help. We truly envy all of the people out there with no deed restrictions.

If you want to take beautiful night sky pictures with your DSLR and you live between 15 degrees and 55 degrees north latitude you might want to check out OpenAstroTracker. If you have a 3D printer it will probably take about 60 hours of printing, but you’ll wind up with a pretty impressive setup for your camera. There’s an Arduino managing the tracking and also providing a “go to” capability.

The design is over on Thingiverse and you can find code on GitHub. There’s also a Reddit dedicated to the project. The tracker touts its ability to handle long or heavy lenses and to target 180 degrees in every direction.

Some of the parts you must print are specific to your latitude to within 5 degrees, so if you live at latitude 43 degrees, you could pick the 40-degree versions of the parts. So far though, you must be in the Northern hemisphere between 15 and 55 degrees.

What kind of images can you expect? The site says this image of Andromeda was taken over several nights using a Soligor 210mm f/4 lens with ISO 800 film.

Not bad at all! Certainly not the view from our $25 department store telescope.

If you’d rather skip the Arduino, try a cheap clock movement. Or you can replace the clock and the Arduino with yourself.

Space is big. Really big. Yet on TV and movies, enemy spacecraft routinely wind up meeting at roughly the same spot and, miraculously, in the same orientation. If you’ve ever tried to find something smaller than the moon in a telescope, you’ll appreciate that it isn’t that easy. There are plenty of tricks for locating objects ranging from expensive computerized scopes with motors to mounting a phone with Google Sky or a similar program to your telescope. [DentDentArthurDent] didn’t use a phone. He used an Arduino with an outboard GPS module.

You still have to move the scope yourself, but the GPS means you know your location and the time to a high degree of accuracy. Before you start an observing session, you simply point the telescope at Polaris to calibrate the algorithm, a process which in the northern hemisphere is pretty easy.

The telescope in question is a Dobson, so is easy to move and easy to sense its position using potentiometers and an A/D. The project also includes a detailed description of the math used to convert the time, latitude, longitude, right ascension, and declination into position data. One of four LEDs show if you should move up, down, left, or right. When you are on target, all four LEDs light. We assume you should use red LEDs and a red LCD filter so you don’t ruin your night vision.

There are a few sources of error and [Arthur] does a great job of analyzing and correcting each one. The project even has a nice 3D printed case. The database only contains 45 objects but it is easy to add more. We wondered if it wouldn’t have been better to use a larger computer such as a Raspberry Pi to get the stellar data — maybe even from the Internet — and rely on the Arduino to just manage the position sensing and direction indication, but then again, this works and it is very inexpensive.

This isn’t the first Arduino telescope finder we’ve seen. The last one even had a touchscreen.

[gocivici] threatened us with a tutorial on positional astronomy when we started reading his tutorial on a Arduino Powered Star Pointer and he delivered. We’d pick him to help us take the One Ring to Mordor; we’d never get lost and his threat-delivery-rate makes him less likely to pull a Boromir.

As we mentioned he starts off with a really succinct and well written tutorial on celestial coordinates that antiquity would have killed to have. If we were writing a bit of code to do our own positional astronomy system, this is the tab we’d have open. Incidentally, that’s exactly what he encourages those who have followed the tutorial to do.

The star pointer itself is a high powered green laser pointer (battery powered), 3D printed parts, and an amalgam of fourteen dollars of Chinese tech cruft. The project uses two Arduino clones to process serial commands and manage two 28byj-48 stepper motors. The 2nd Arduino clone was purely to supplement the digital pins of the first; we paused a bit at that, but then we realized that import arduinos have gotten so cheap they probably are more affordable than an I2C breakout board or stepper driver these days. The body was designed with a mixture of Tinkercad and something we’d not heard of, OpenJsCAD.

Once it’s all assembled and tested the only thing left to do is go outside with your contraption. After making sure that you’ve followed all the local regulations for not pointing lasers at airplanes, point the laser at the north star. After that you can plug in any star coordinate and the laser will swing towards it and track its location in the sky. Pretty cool.

To photograph the stars, you need a gadget that can track the revolving night sky in a perfectly timed arc. Otherwise all you’ll see is streaks and blurs.

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Make Galileo’s Finger: and open source star finder. via instructables:

Given the opportunity to use one of the Intel Galileo boards, we wanted to build something that would honour Galileo’s memory and pay tribute to his discoveries. What better way than to do something related to his primary focus – astronomy.
Being an avid astronomer, and loving being able to look up into the night sky and know what star or planet I’m looking at, I thought a cheap, accurate laser pointer would be perfect.
With the right idea in mind, and three weeks in which to do it, my partner and I set off coding and building.

Build An Open Astronomy Learning Tool With Arduino - [Link]