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Old NexStar GPS motor control and hand control firmware update info

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#1 12Bass

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Posted 22 April 2018 - 07:33 AM

Old NexStar GPS motor control and hand control firmware update info:

 

Contrary to what's published, supposedly "non-upgradable" old NexStar GPS telescopes are able to be updated to more recent firmware by using external programmers.  Early (c. 2001) NexStar GPS Motor Control boards with MC1.0 and MC2.0 do not require an expensive board replacement; rather, they can easily be flash updated with the latest MC4.06 firmware using any compatible PIC programmer (e.g. PICkit).  NexStar GPS Hand Controls with the original HC1.2 firmware can also be flashed to either HC1.6 or HC2.2 using a universal programmer (e.g. TL866) with a PLCC32 adapter.  Andre Paquette from AstroGeeks used to offer these firmware upgrades as a service but ceased doing so a few years ago.

 

Because it has been well over a decade since the NexStar GPS was discontinued, I suspect that the actual number of NexStar GPS telescopes that are still out there with the original firmware is rather low. Thus I will not be writing an extensive tutorial on firmware updating for a potentially nonexistent audience. Instead, I will simply outline the basic flashing procedure and offer to provide more detailed assistance if it should be required by someone who is still stuck with old firmware (e.g. MC1.0/MC2.0, HC1.2) and wants to update.

 

Andre Paquette has graciously provided the required firmware binaries which are available here: https://groups.yahoo...NexStarGPS/info in a directory named 'Andre Stuff'.  Note that it is necessary to become a member of the group before the firmware files can be downloaded.

 

Flashing Procedure:

 

Updating early MC boards with MC versions 1.0 and 2.0 requires flashing with an external PIC programmer via the MC board's program header.  The most recent/best MC firmware is mc1_0406.hex (MC4.06), which can be found in the directory shown above.  A PICkit or TL866A or any other universal programmer should work, as long as it is capable of flashing PIC16F876 devices.  For anyone who still has such an old MC firmware on their NexStar GPS, this procedure potentially saves them the unnecessary expense of buying a new motor control board and provides much more accurate and nearly silent tracking.

 

Updating a NexStar version 1.2 hand control with HC1.6/2.2 is somewhat more involved as it requires the removal of two AT49F040 PLCC32 EPROMs from the handset using a PLCC extractor and flashing them with a universal programmer via a PLCC32 adapter. However, the procedure is actually quite simple if you have the right tools.  The HC firmware required is hc16_even.bin & hc16_odd.bin or hc22_even.bin & hc22_odd.bin (depending on whether the user wants to upgrade to HC1.6 or HC2.2, respectively), which can also found in the Andre Stuff directory noted above.  These newer versions add some important features like compass calibration along with bug fixes.

 

I upgraded my NexStar GPS hand control from HC1.2 to HC2.2 using a TL866A universal programmer, although any similar type of programmer should work as long as it is compatible with AT49F040 devices. Note that no higher upgrade than HC2.2 is possible with the original NexStar GPS hand control and also that HC2.2 is the last NexStar hand control firmware which supports the very user friendly GPS north and level alignment (which was eliminated due to a lawsuit with Meade).  I prefer the semi-automated GPS alignment to Celestron's more recent alignment options.

 

Anyone wanting to update the firmware on their old NexStar GPS is welcome to respond to this thread if they require further assistance.


Edited by 12Bass, 22 April 2018 - 06:01 PM.

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#2 junomike

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Posted 23 April 2018 - 06:42 AM

This is good to know for those that can use it. I'm not quite tech-savy enough to do such a mod but luckily my NS11GPS already had the upgrade when i bought it (used) several years ago.


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#3 12Bass

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Posted 23 April 2018 - 01:38 PM

This is good to know for those that can use it. I'm not quite tech-savy enough to do such a mod but luckily my NS11GPS already had the upgrade when i bought it (used) several years ago.

At this point, I doubt that there are very many NexStar GPSs out there with the original (c. 2001) firmware.  However, I bought such a scope last year and had to figure out how to update it myself.  I thought it might be helpful to post this information for anyone else who might find themselves in a similar position.  This information would probably have been much more useful a five or ten years ago....



#4 Patrick66

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Posted 04 May 2018 - 04:32 PM

I have a question, when I was taking the cover off the bottom of my nexstar 11 to check out connections , I popped the connectors off of the serial  board. Does anyone have a diagram or a picture of where the connectors to on the serial board? I'm having a lot of trouble getting any information.

 



#5 mbolen

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Posted 18 July 2018 - 10:48 AM

I am one of the rare people that has a NexStar GPS with its original firmware (v 1.6 for the hand controller, and v 1.0 for MC). I recently acquired it, knowing full-well of the firmware version it had, but it is such a nice scope with great optics and huge aperture (I have the 11). Of course, I’ve been looking online for a new MC board so I can update everything, but have been unsuccessful. This gives me great hope!! I’m not a programmer, though, and very little of your instructions make sense to me. Any suggestions for me? I would be willing to pay a programmer to do it, would the be able to do it with the instructions above?

Thank!

Edited by mbolen, 18 July 2018 - 11:00 AM.


#6 12Bass

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Posted 19 July 2018 - 03:15 AM

I am one of the rare people that has a NexStar GPS with its original firmware (v 1.6 for the hand controller, and v 1.0 for MC). I recently acquired it, knowing full-well of the firmware version it had, but it is such a nice scope with great optics and huge aperture (I have the 11). Of course, I’ve been looking online for a new MC board so I can update everything, but have been unsuccessful. This gives me great hope!! I’m not a programmer, though, and very little of your instructions make sense to me. Any suggestions for me? I would be willing to pay a programmer to do it, would the be able to do it with the instructions above?

Thank!

Hi,

 

A few months ago, Mike Swanson asked if I would write a more detailed flashing guide.  However, I recently moved halfway across Canada and am still in the process of getting things set up here in Victoria.  I still intend to submit a better guide sometime in the next few months.  However, if anyone needs flashing help before then, please let me know and I will do what I can to walk you through it.

 

Updating the original MC 1.0 firmware should be reasonably easy for someone with a modicum of experience with electronics.  The MC board is accessible by removing six screws from the fork with the handle on it.  Updating requires the fabrication of a programming adapter which connects a PIC programmer to the PGM header on the MC board, plus 5V and ground.  The latest mc1_0406.hex should be flashed with the config bits set to 0x3f72 and the EEPROM area set to all zeros except for the last bit which should be 0x01.  The whole procedure should take less than an hour to complete.   

 

My MC board was not responding after the initial MC 4.06 flash using the programmer.  However, I was able to get the MC board working by flashing it again with Celestron's MCupdate program via the mount's PC port (requires serial PC cable).

 

There is little to be gained in updating the old 1.6 HC to version 2.2.  While the flashing procedure is fairly simple if you have the necessary programmer and PLCC32 adapter, the old handsets have now been superseded by newer hardware with HC versions 4 and 5.  HC 1.6/2.2 are incompatible with SkySafari 5 and up.  That said, HC 1.6 is stable and remains very usable if the newer features and compatibility with recent software are not required.  Plus, HC 1.6 uses the very convenient automatic North & Level GPS alignment which was replaced with SkyAlign in later firmwares due to a lawsuit with Meade


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#7 Don W

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Posted 20 July 2018 - 05:11 PM

I still have the original GPS firmware on mine. I like it but could not get any WIFI to work. Finally I got a newer handset and cobbled together a WIFI setup and it works great. When I want to observe, I just use the old GPS unit. Got the best of both worlds.



#8 12Bass

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Posted 20 July 2018 - 08:09 PM

I still have the original GPS firmware on mine. I like it but could not get any WIFI to work. Finally I got a newer handset and cobbled together a WIFI setup and it works great. When I want to observe, I just use the old GPS unit. Got the best of both worlds.

Yes, the original HC 1.6/2.2 works very well, IMO.  Which program are you using with WiFi?  Haven't tried WiFi, but my HC 2.2 works with my PC using NexRemote as well as my phone using SkySafari 4 with Bluetooth.  Simulation Curriculum seems to have changed something in the telescope control commands which renders SkySafari 5 and up incompatible with older handsets.



#9 Don W

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Posted 20 July 2018 - 10:10 PM

Skysafari. Not sure of the version.



#10 junomike

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Posted 21 July 2018 - 07:48 AM

I still have the original GPS firmware on mine. I like it but could not get any WIFI to work. Finally I got a newer handset and cobbled together a WIFI setup and it works great. When I want to observe, I just use the old GPS unit. Got the best of both worlds.

Don, Which WiFi device are you using?



#11 Don W

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Posted 21 July 2018 - 11:23 AM

Umm.........something I cobbled together. Got a WIFI dongle off Amazon, a gender converter and a USB battery pack to power it. Got the idea here in Nexstar.

 

wifi.jpg

 



#12 junomike

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Posted 21 July 2018 - 12:45 PM

Thanks!



#13 JMP

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Posted 24 July 2018 - 09:03 PM

I have an older N11 GPS. It's been 20 years since I was a tech, I even bought a TL866a progammer. But I'd either need some coaching or just send the controller bd to someone else. I bought a spare base so I have some parts to work with.

 

Jeff Phillips

Eugene, Oregon



#14 12Bass

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Posted 25 July 2018 - 01:33 AM

I have an older N11 GPS. It's been 20 years since I was a tech, I even bought a TL866a progammer. But I'd either need some coaching or just send the controller bd to someone else. I bought a spare base so I have some parts to work with.

 

Jeff Phillips

Eugene, Oregon

If you already have a TL866A, then you've got pretty much everything needed to flash the MC firmware.  After that, what's necessary is the mc1_0406.hex (available from here), and fabricating a programming cable to connect to the MC board. 

 

I'm willing to update older MC boards here in Victoria, BC.  However, I'm not sure about the particulars regarding shipping across the border.


Edited by 12Bass, 25 July 2018 - 01:36 AM.


#15 Geo.

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Posted 25 July 2018 - 02:50 PM

I have a question, when I was taking the cover off the bottom of my nexstar 11 to check out connections , I popped the connectors off of the serial  board. Does anyone have a diagram or a picture of where the connectors to on the serial board? I'm having a lot of trouble getting any information.

Maybe this will help.

 

Main Pl Junct.jpg


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#16 Patrick66

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Posted 25 October 2018 - 01:41 PM

Thank you everyone for taking the time to help, I really appreciate it! 



#17 RogerClark

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Posted 04 November 2018 - 05:17 PM

@Sputnik

 

Thanks for posting the information about the files on Yahoo etc.

 

I've looked in my Nexstar 4GT hand controller and it has Holtek HT27C010 (  http://ec66.com/mark...et/HT27C010.pdf ) which are "128K × 8-Bit EPROM", which are soldered onto the board i.e not in holders.

Where as the Atmel AT49F040 is "4-Megabit (512K x 8)"  (http://www.mouser.co...el_AT49F040.pdf)

 

I checked all the bin files, and even the hc12 files, seem to have non zero (0xff) data in them above the 128k boundary.  So none of these firmware would fit.

 

Looking on the HC board, mine has NXW210 Rev C, written on it, and it also has 2003 written on it.

 

The main processor is a PIC17C756A-33/L

 

I must admit, I'm a bit surprised that the board is dated 2003, because I bought the telescope in either 2005 or 2006, and only use it occasionally.

 

 

Recently I thought I'd get the telescope working again, and have started to convert the old RS232 connection to USB and also to Wifi (using a ESP8266 module with Wifi to serial firmware I installed on it).

 

However the RS232 command set in the HC is 1.2 and no longer seems to be supported by Stellarium (and I suspect not supported by much else), as it has very few commands and the ones it has, use upper case letters e.g "E" instead of "e" to get az/ele

 

The RS232 connection in the firmware is also know to be buggy and can hang up, which needs the telescope to be rebooted before it works again.

 

I was hoping that I could upgrade the firmware, but this now looks quite unlikely, as I'd need to take a big risk by removing the EEPROMs and attempting to solder in the Atmel ones instead, which is a difficult job, and risks completely breaking the HC, and making the telescope useless unless I buy a replacement HC, at a cost of several hundred dollars - if I can get get hold of one at all.

 

Since I just want to do some basic control from Stellarium or possibly from some of Android Apps, (which have Wifi support), I'm now experiment with intercepting the command, and changing the letter e.g from an "e" to an "E" and also modifying the response from the telescope (because, for example, the E command only returns low resolution position, 16 bit values, where as the "e" command returns 32 bit values)

 

I think this should be fairly easy to program, but I'm not sure if some of the Android Apps expect the telescope to respond to more than just the basic goto commands, so the ESP8266 (or another MCU for USB  - a STM32F103) will need to spoof responses to other commands if necessary to appease the apps ;-)



#18 RogerClark

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Posted 04 November 2018 - 05:19 PM

BTW. On a related point. The other option is to connect directly to the motor unit, and I'm a bit surprised that no one has done something like use a Raspberry Pi (zero W) etc in place of the HC and control the telescope from web pages over wifi.

 

But I think the problem was writing the alignment software :-(

 

I'm not sure if its even worth the risk updating the motor firmware, since it looks like my Nexstar #11041 is even older than I'd realised :-(


Edited by RogerClark, 04 November 2018 - 05:26 PM.


#19 Michael_Swanson

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Posted 04 November 2018 - 08:32 PM

BTW. On a related point. The other option is to connect directly to the motor unit, and I'm a bit surprised that no one has done something like use a Raspberry Pi (zero W) etc in place of the HC and control the telescope from web pages over wifi.

 

But I think the problem was writing the alignment software :-(

 

I'm not sure if its even worth the risk updating the motor firmware, since it looks like my Nexstar #11041 is even older than I'd realised :-(

You can connect a small PC (running Windows, not Linux) via the PC Port on the base and run the scope with NexRemote on that small PC.  Then, it is possible to use ASCOM to connect to NexRemote, WiFi Scope (http://mainsequencesoftware.com) to connect to ASCOM and then you can connect SkySafari on a smartphone/tablet to control your scope.  In theory :-)

 

You can definitely at least go as far as NexRemote.  A tablet running Microsoft Remote Desktop client could then provide remote access to NexRemote. 

 

Best regards,
Mike Swanson
Author of "The NexStar User's Guide II"
Author of "The NexStar User's Guide"
Author of "NexStar Observer List"

http://www.NexStarSite.com 


Edited by Michael_Swanson, 04 November 2018 - 08:33 PM.


#20 RogerClark

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Posted 04 November 2018 - 09:04 PM

@Apollo

 

Thankyou....  I didn't realize I could do that.

 

I'll need to double check the Serial voltages on that connection, but I suppose since its internal to the telescope i.e between the HC and the base / motor unit, that its 5V serial,

 

I have plenty of USB to serial converters, and I've already converted the HC to use a USB to serial converter, as all but one of my old PC's don't have real RS232 (12V).

 

 

 

Anyway... Thanks again.


Edited by RogerClark, 04 November 2018 - 09:21 PM.


#21 RogerClark

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Posted 04 November 2018 - 10:04 PM

Well, I gave that a try, but it doesnt work either.

 

NexRemote fails to connect to the telescope.

 

I've double checked the connections, and its all OK, because if I open a terminal to the serial port and send the E command, it get the Az/el

 

e.g.

 

E3D85,27C8#

 

I've selected the same com port (11) and I've tried Mount Model as GT Series, and also tried the "All models", but both fail to connect.

 

Just to confirm.  NexRemote connects to the RS232 port on the bottom of the hand controller and not into the base ?

 

(I suspect everything in my scope is too old to be compatible any more :-(   )



#22 Michael_Swanson

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Posted 05 November 2018 - 12:43 AM

Hi Roger,

NexRemote works through the port on the bottom of the hand control when the hand control is version 4 or higher. That is why I stated you must connect via the PC Port on the base since you already indicated your hand control is version 1.2. For the cable required, visit this page of my website and see the article 'PC Port Cable':
ttps://www.nexstarsite.com/PCControl.htm

Additionally, you may need to update your motor control firmware using these instructions:
https://www.nexstars...pgradeHowTo.htm

Best regards,
Mike Swanson
Author of "The NexStar User's Guide II"
Author of "The NexStar User's Guide"
https://www.NexStarSite.com

#23 RogerClark

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Posted 05 November 2018 - 05:42 AM

@Apollo

 

Thanks.

 

I have already modified my hand control to have a USB to Serial converter, and using a terminal program I can send commands

 

However the only commands that it responds to are the ones labelled 1.2 in this doc

 

https://s3.amazonaws...tarcommprot.pdf

 

If I send the version command, the hand controller sends back the "e #"

 

I've checked what the actual bytes of these values are and its sending back

 

101

0

35

 

e = 101

(the space) is showing as a space as its a non printable character

and the 35 is the #

 

I'm not entirely sure what this means, perhaps the version is 1.01 ??

 

 

Re: Motor firmware update

My telescope seems too old to use any of the update methods, listed on https://www.nexstars...pgradeHowTo.htm  but I have a PicKit programmer kicking around somewhere, plus various other programmers, which may be able to update the Pic firmware

 

However I'm quite reluctant to do this, since the EEPROMs in my HC predate any of the ones listed in this thread and even V1.2 hand controller firmware is too big to fit in my EEPROMs,  so I suspect there is strong possibility that if I reflash the motor control firmware it may no longer be compatible with my ancient hand controller

 

 

In the mean time, I've continued to work on my microcontroller based command converter, and the microcontroller can now convert the "e" command to an "E" and then converts the response e.g. 3D6E,27C8#  to 3D6E0000,27C80000#

 

I think doing command conversion for all the 1.2 (or version 1.01 ??) commands if my safest course of action, as I don't want to brick the telescope completely, while trying to get it to work with PC, because the old fashioned manual operation of the hand controller does work OK.



#24 RogerClark

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Posted 05 November 2018 - 05:37 PM

BTW.

 

When I get chance I'll have a look at what commands NexRemote is sending. Potentially its attempting to use the AUX commands which the HC passes straight through to the motor unit.

But I'm not sure my HC supports these either



#25 Michael_Swanson

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Posted 05 November 2018 - 07:39 PM

BTW.

 

When I get chance I'll have a look at what commands NexRemote is sending. Potentially its attempting to use the AUX commands which the HC passes straight through to the motor unit.

But I'm not sure my HC supports these either

Hi Roger,

 

Nope, hand control 1.2 does not support the pass-through command which is specifically why NexRemote will not work when connected to the port on the bottom of that version of hand control.  

 

Re-reading your first post, I'm not sure which scope you actually have.  When you stated "hand control 1.2" I assumed NexStar 11 GPS, particularly since this string is about the NexStar GPS mount.  But, you also mentioned your NexStar 4GT.  Which mount do you have as some of my responses above are only applicable to the NexStar GPS, not the NexStar GT.

 

Best regards,
Mike Swanson
Author of "The NexStar User's Guide II"
Author of "The NexStar User's Guide"
https://www.NexStarSite.com




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