NexStar Resource Site

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Firmware Versions on the Celestron CGE Series

Celestron CGE scopes have two sets of processors. There are processors in the hand control (HC) and there are processors in the base of the scope in a section known as the motor control (MC). The MC firmware can be updated by the owner (read this). 

There have been three versions of hand control available for the CGE:

  • Hand control 3.0 and 3.01.  Hand controls prior to version 4 can NOT be updated.
  • Hand control version 4.X.  This hand control can be updated by the owner and was available for purchase from January 2006 through summer 2012.  Read this for info on purchasing the upgradeable hand control and this for step by step instructions on upgrading the firmware.
  • The NexStar+ hand control.  This hand control can be updated by the owner and is available for purchase since February 2012.  Read this for info on this new hand control and this for step by step instructions on upgrading the firmware.  NOTE:  the CGE may have experienced intermittent NO RESPONSE errors with the original NexStar+ hand control but Celestron made a change to the NexStar+ hardware in 2017 or 2018 and new NexStar+ hand controls should work well with the CGE.

For additional details about features on newer versions, check the Manuals section of this web site.

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NexStar+ Hand Control

NOTE:  the CGE may have intermittent problems with the NexStar+ hand control depending upon the version of electronics hardware in the mount - the reported symptom is intermittent NO RESPONSE errors on the hand control.  There is no known fix for this problem.

Celestron has posted an official page detailing all firmware versions for the NexStar+ hand control:
https://www.celestron.com/pages/firmware-update-history
Check back periodically for updates or click the link to sign up for notifications.

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Version 4 Hand Control
(firmware files are named GEM)

  • 4.22 - Fixes the date when the scope is used with a GPS receiver that returns a date 20 years in the past.
  • 4.21 - Fixed bugs related to tandem operation (OTA orientation), Meridian Mode and land objects.
  • 4.20 - Added "Custom Rate 9": the ability to set the maximum slew rate during a GoTo (requires motor control version 5.20 or higher).  Fixed a problem with a runaway slow slew if a GoTo is too near the meridian flip point.  No Response errors now give a "Press UNDO to continue" option.  For mounts with a GPS module in use, changed the messages displayed to clarify when the GPS was still attempting a link and when it was successful.  Fixed and error when syncing on stars in southern hemisphere via the RS-232 sync command (for example, from a planetarium program running on a laptop).
  • 4.19 - Adjust communication protocol to assist MCupdate.  Fixed an error in the GoTo RA-Dec menu item.  Hand Control now reports immediately if the are communication ("No Response") difficulties at start up.
  • 4.16 - Corrects alignment system errors for use in the Southern Hemisphere.  Fixed error when using SAO stars (selected from the STAR button) as alignment objects.
  • 4.15 - Introduced with the CGEM, this version includes several changes.  All-Star Polar Alignment (ability to perform polar alignment on any star, not just Polaris and Sigma Octanis) and tandem support (ability to turn the RA axis 90 degrees and mount multiple optical tubes side-by-side) are two new features.  The hand control now uses precession to calculate current coordinates rather than using static J2000 coordinates.  After polar alignment it is no longer necessary to repeat the star alignment.  User is now prompted automatically for the time during alignment if the RTC is turned off and a GPS module is not in use.  Read the manual for the CGEM (found in the Manuals section of this web site) for details on how this all operates.  NOTE:   This version is largely unusable in the Southern Hemisphere.
  • 4.13 - This version allows the motor control (MC) firmware to be upgraded via the port on the bottom of the hand control.
  • 4.12 - The most significant change in this version is variable brightness control for the display and buttons - values are from 0 (off) to 8 (full brightness).  There is also a fix that reduces (but does not eliminate) the chance that the display comes up blank the first time you power up, a problem much more prevalent in cold weather.  The fix on those occasions when it does still come up blank remains the same - turn off the power, wait a couple of seconds and turn on the power again.  The Version menu item has been changed - it now displays the mount model after displaying the HC and MC versions.
  • 4.10 - The most significant change in this version is Sync and multiple mount calibration stars.  Sync is available both via the hand control and via PC software (TheSky, Starry Night, etc.).  This provides very accurate GoTo pointing in the area of the sky where the Sync is performed and it allows the PC software to match with the actual position the scope is pointed to.  Multiple mount calibration stars take the place of the previous use of one calibration star for determining cone error and the Dec switch/index mark offset resulting in much improved pointing accuracy.  Other new features:  a display of the polar alignment error, Solar System Align routine, the Sun is now available as a GoTo and alignment object, "RA" and "Dec" are used in most places in the menus rather than "Alt" and "Azm", and the new ability to start PEC playback and proceed with normal use of the hand control.

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Non-upgradeable Hand Control

  • 3.01 -  Original version on the CGE mount.
  • 3.0 - A version which seemed to have leaked out on accident - thus far seen on only one scope.  Differences between this and 3.0 seem to be minor.  This version may be slightly less accurate during the Polar Alignment routine, the Dec Switch calibration value may occasionally display incorrectly and the Version command on the menu will display the minor version of the MC firmware with only one digit instead of two - in other words, 5.06 will be displayed as 5.6.

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MC Versions

  • 5.20 - Support for "Custom Rate 9": the ability to set the maximum slew rate during a GoTo (requires hand control version 4.20 or higher).  The final GoTo approach is now faster and quieter.
  • 5.14 - Corrects a potential problem with the cordwrap prevention feature.
  • 5.07 - An official version.  Rate 1 is now 50% of sidereal while rate 2 is 100% of sidereal.  This is the first version to support Celestron's free PECTool utility.
  • 5.06 - An official (non-beta) version available for download from Celestron.  Improved anti-backlash, improved PEC performance, slight improvement on sidereal tracking rate.
  • 41.36 - This is a beta (test) version.  Improves PEC performance.
  • 5.05 - Reportedly fixed autoguider problems including runaway slew when autoguiding.  Also reportedly fixed occasional runaway slew during regular GoTo operations.  That said, it is believed these problems were not actually fixed until version 41.36 .
  • 40.43 - This is a beta (test) version which probably became official version 5.05.  It was available for a short period of time on the Celestron web site and was removed when 5.05 was released.
  • 5.02 - Original version on the CGE mount.
  • 5.0 - A version which seemed to have leaked out on accident - thus far seen on only one scope.  It is definitely recommended the mount be updated to the latest MC firmware.

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Determining Versions

Use the Version option on the Utility menu.


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Michael Swanson
 
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