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Have you ever considered updating the firmware of your Celestron NexStar? My hand control was running version NXS 4.13 and my motor control was running version 5.13, so updating my firmware was long overdue. In case you didn’t know: the Celestron NexStar 5SE contains two separate computers that each run their own firmware version. You can find the versions of your telescope’s firmware via the Utilities Version menu:

Why would you update your firmware to begin with? You can be sure that your telescope will run with more precision and less bugs with a newer version of the firmware. And amazingly, my NexStar is now more quiet than it was before! A very good reason to have updated the motor control firmware indeed! Read all about it here if you are curious.

The Celestron firmware update software is available only for the Windows operating system. So I decided to update my telescope’s firmware via Parallels for OSX, since I am using a Macbook Pro with OSX.

First I had to get the correct cable(s), though. To update the telescope’s firmware, you either need an old computer that still has an RS232 serial port, or a USB-to-serial adapter. With my Macbook Pro, I had to opt for the latter.

I bought a Plugable USB to RS-232 DB9 Serial Adapter (Prolific PL2303HX Rev D Chipset) on amazon.com for $12.95. You also need an rs232 cable that connects to the bottom of your hand control. Read all about it here. I got my rs232-to-handcontroller cable at our local Celestron dealer, http://www.ganymedeshop.nl/. Here you can see how that cable connects to the hand control:

I downloaded two installers from the Celestron site. One to update the motor control firmware (MCUpdate), the other to update the hand control firmware (HCUpdate). After installation, I started with the motor control update. MCUpdate allowed me to download the latest version via the web. You can see how this looks further below, where I describe the hand control firmware update, which uses a very similar procedure. I had to connect to COM3 in order to communicate with the telescope, but your COM settings may differ.

After clicking on “Begin programming”, the motor control firmware was updated. It took a few minutes to complete, during which time the hand control was in a locked state.

Updating the Hand Control firmware was very similar. Again, I had to choose COM3. But in order to update the hand control firmware, I had to hold down the INFO and UNDO buttons on the hand control while turning on the power. This resulted in the following message:

Like MCUpdate, HCUpdate also let me download the latest firmware version from the web:

After clicking “Begin programming”, the software again showed me the progress of the firmware update:

For me the whole procedure was completely painless. It took a few minutes to update each firmware version. Be sure to follow all the prompts, both from the Celestron update software and those on the hand control of your NexStar 5SE. For instance, at a certain point during the procedure I had to power cycle the telescope. But when all was finished, the Utilities Version menu happily showed me that the new versions were installed:

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