Planet Arduino

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.

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.

We’ve all enjoyed looking up at a clear night sky and marveled at the majesty of the stars. Some of us have even pointed telescopes at particular celestial objects to get a closer view. Anyone who’s ever looked at anything beyond Jupiter knows the hassle involved.  It is most unfortunate that the planet we reside on happens to rotate about a fixed axis, which makes it somewhat difficult to keep a celestial object in the view of your scope.

It doesn’t take much to strap a few steppers and some silicon brains to a scope to counter the rotation of earth, and such systems have been available for decades. They are unfortunately quite expensive. So [Dessislav Gouzgounov] took matters into his own hands and developed the rDuinoScope – an open source telescope control system.

Based on the Arduino Due, the systems stores a database of 250 stellar objects. Combined with an RTC and GPS, the rDunioScope can locate and lock on to your favorite nebula and track it, allowing you to view it in peace. Be sure to grab the code and let us know when you have your own rDuinoScope set up!

There’s many complex systems for automatically pointing a telescope at an object in the sky, but most of them are too expensive for the amateur astronomer. [Kevin]’s Arduino ST4 interface lets you connect your PC to a reasonably priced motorized telescope mount, without ripping it apart.

The ST4 port is a very basic interface. There’s one pin per direction that the mount can move, and a common pin. This port can be added to just about any motorized mount with some modification to the controller. To connect to an Arduino, a TLP521-4 quad optoisolator is used. This keeps the Arduino and PC fully isolated from the motor circuits. but lets the Arduino take control of the mount.

With the hardware in place, [Kevin] cranked out some software which is available on Google Code. A simple Arduino sketch provides the USB interface, and a custom driver allows the ASCOM Platform to control the mount. Since many astronomy software tools support ASCOM, this allows the mount to be controlled by existing software.

With the interface in place, the mount can be used to find objects (GOTO) and automatically follow them with high accuracy (autoguiding). You can watch the telescope move on its own after the break.