This Arduino failsafe protects an amazing backyard observatory

Nothing quite compares to the feeling of looking up at the cosmos on a dark night, and even an affordable telescope can enhance that experience. But if you’re willing to spend the time and money, you can take things much further. That’s what Redditor CosmicRuin did when they built an amazing backyard observatory. And they recently designed this Arduino-based failsafe to protect that observatory in the event of a power outage.

CosmicRuin’s Super RobDome observatory will make every amateur astronomer seethe with envy. It is, essentially, a smaller version of the kinds of serious observatories you’ll see on dark mountaintops around the world. And like those, this observatory has a dome. That is there to protect the telescope and other equipment from the elements, and to block as much of the surrounding light as possible.

But if the mains power fails, the dome wouldn’t be able to close and provide protection. CosmicRuin used an Arduino UNO Rev3 board to detect such a power outage and automatically close the dome if it does, while running on power from a battery backup system.

The Arduino monitors mains AC voltage through a MCP6002-based Grove sensor. If that drops below a set threshold, either from a brownout or a complete blackout, it will flip a relay connected to the dome’s controller and that tells it to move to the “home” position and close the cover. Because it runs on a battery backup, it can do that even when the power is completely out.

Now CosmicRuin can rest easy knowing their expensive equipment is safe at all times.