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
There have been three versions of hand control available for the CGE:
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.
for info on purchasing the upgradeable hand control and
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
for info on this new hand control and
for step by step instructions on upgrading the firmware. NOTE:
the CGE may have intermittent problems with this hand control depending upon
the version of electronics hardware in the mount - the reported symptom is
intermittent NO RESPONSE errors on the NexStar+ hand control.
For additional details about features on newer versions, check the
Manuals section of this web site.
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 document detailing all firmware versions
for the NexStar+ hand control:
Check back periodically for updates.
Version 4 Hand Control (firmware files are named GEM)
- 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
- 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
- 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
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.
- 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
- 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
- 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.
Use the Version option on the Utility menu.