Building the Full Version of the Nexus eFinder

After weeks of anticipation, I finally completed the full version of the Nexus eFinder on December 9. The journey wasn’t entirely smooth—mainly because the daughterboard, kindly provided by Keith Venables, was stuck in customs for almost two weeks. But once it arrived, the real fun began!

The Setup

To house the components, I needed a new 3D-printed box. The camera and the Raspberry Pi Zero 2 fit perfectly, but integrating the daughterboard was a bit tricky. The Pi wasn’t mounted low enough in the box, which made positioning the daughterboard more challenging than expected. After some adjustments, everything came together nicely.

The finished Nexus eFinder

Firmware Upgrade

On December 10, I installed the latest Nexus DSC Pro firmware, which supports the full version of the Nexus eFinder. This was a big step forward, although the Goto++ functionality isn’t available yet—it’s planned for a future firmware update. I’m looking forward to that enhancement!

The camera module installed in the eFinder box.

First Telescope Integration Attempt

That same day, I tried attaching the Nexus eFinder to my telescope. Unfortunately, I discovered I needed a longer USB-A to USB-C cable to make it work. I ordered the cable immediately, and it has already arrived, so I’m ready for the next attempt.

First Light (Almost)

The sky wasn’t completely clear on December 10, but I managed to focus the lens of the Nexus eFinder. Now, all that’s left is to wait for a truly clear night to test the system with my Obsession telescope. I’m excited to see how it performs under real observing conditions!

The Raspberry Pi installed in the eFinder box.

Why Goto++ Matters

One of the most exciting upcoming features for the Nexus eFinder is Goto++. This functionality takes telescope pointing accuracy to the next level by combining plate-solving with your GoTo system. Here’s why it’s such a game-changer:

• Ultra-Precise Targeting
  After a GoTo command, Goto++ uses an image from the eFinder to plate-solve and confirm the exact position of the telescope, then corrects any deviation. Your target ends up perfectly centered.

• Error Correction
  Mechanical imperfections, flexure, or alignment errors can cause drift. Goto++ recalibrates after each slew, reducing cumulative errors during long sessions.

• Faster Workflow
  No more manual centering or syncing. The system automatically adjusts after each GoTo, saving time for finding faint objects during visual observing.

In short, Goto++ turns your GoTo system into a smart, self-correcting tool, making observing more efficient and accurate.

The daughter board installed in the eFinder box.