GoTo Dob Firmware

[knightrider]

Good evening guys,

My skywatcher goto dob came preloaded with synscan firmware v3.08.
I realise there has been some changes in the firmware releases lately but that more directly affect the EQ boys and girls in the updates.

I there any advantage to upgrading the firmware to a newer version for a AZ mount? (eg v3.35/34)

[Steffen]

I'd go to version 3.27, it seems reasonably functional. The latest version (3.35) has very useful polar alignment routine (which you don't need for a Dob) but some new bugs, too.

Cheers
Steffen.

[knightrider]

I had a look at the skywatcher site and 2.27 doesn't seem to be listed. 3.08 seems to work relatively well except for I've noticed it seemed to keep the lunar tracking rate after viewing the moon. I've only noticed this sometimes.

The new versions seem to carry too many EQ setup features which are irrelevant to AZ, and I needlessly have to skip through a large part of the setup features.

[Steffen]

Hm, there's probably a reason for that. It appears that 3.27 is an EQ only version. They unified the EQ and AltAz versions only as of 3.32…

Cheers
Steffen.

[knightrider]

I zapped 3.35 onto the HC tonight. I did notice it has the Caldwell catalogue which 3.08 didn't have. That's a plus I guess. Apart from that, if the lunar to sidereal problem is fixed also as the site mentions that would be also a bonus.

I'm yet to test it out still though

[knightrider]

I tried out 3.35 lastnight. I've found it has an issue when you command it to an object where it will alternate back and forth quite a few times from the object and away to another point a few degrees away before it settles down at the point away from the object.

So I've reverted back to 3.08. I don't know if anyone else has found the same thing with 3.35 on their AZ mount?

[Steffen]

Yes, there have been threads about it here on IIS.

The feature is meant to remove pointing errors that stem from backlash in the drive gears. It should only re-approach the object once or twice and then land straight on it. There is a bug that makes it keep going back and forth, and then often stop away from the object.

For me (HEQ5 Pro mount) this only ever happens after I've done a 3-star alignment. It has never happened after a 2-star alignment (I have yet to hear from others confirming this). I find alignment accuracy and repeatability much better with 2-star alignments anyway. My cone error appears to be low (too low to notice for visual), so I just don't bother with 3-star alignments anymore. I do like the polar alignment routine in 3.35, that's why I'm sticking with this version.

Cheers
Steffen.

[acropolite]

I seem to remember reading somewhere that the back and forth thing is corrected when backlash figures are correctly set. Not sure if this is correct but it dies make some sense.

[shenanigans000]

I will shortly be upgrding from 3.08 to 3.35 for my goto Dobby - if the required cable ever arrives!

Will post once I have and let you know if there are any issues.

I too have noticed the lunar / sidereal problem so hopefully 3.35 will fix that.

[knightrider]

That would be awesome greg :)

[shenanigans000]

Well the cable finally arrived. It's actually 2 cables: the first is a USB to serial RS232 port converter cable, the second is the RS232 to RJ45 connector that attaches to the Synscan handset.

Firstly I installed the driver so the computer recognises the serial converter cable - all good.

Unfortunately when I attach the second cable with the Synscan unit attached to it, nothing happens. The Skywatcher firmware updating program scans the COM ports but doesn't see the Synscan unit. Grrrr!

So tomorrow I'll try a different computer, but I suspect the problem lies with the fact that I'm trying to connect via USB to Serial converter (which I must, as my computer doesn't have a serial port).

All this leads me to reflect on the fact that the Synscan doesn't in fact have a USB connection. RS232 serial ports are so '90s !!!

We have two laptops, one netbook and one desktop computer in our household. None of them have a serial RS232 port, all of them have multiple USB ports. Why Skywatcher still supplies handsets in 2013 with a proprietary serial connector is beyond me. Comes down to cost I suppose.

Anyway when (if) I get it all working I'll post again, re the benefits or otherwise of upgrading to V3.35

[knightrider]

I too found my cheap eBay USB to rs232 converter to not work at all.

I went and bought a quality one from my local computer shop for $30 and it registers pretty reliably.

[shenanigans000]

Yeah, I'm thinking that might be the go. I looked on Jcar and they can be had for 29 bucks.

[shenanigans000]

OK - success! I have managed to successfully update to Synscan firmware 3.35

Turns out I was forgetting to hold down the 0 and 8 buttons during power up, to put the hand control in to firmware update mode. Doh!

I'll post here again in a few nights when I've had a chance to fiddle around and see how things actually work.

[knightrider]

Sounds good. When 3.35 is installed onto the AZ handset it doesn't throw in
all the EQ options and setup procedures like the previous versions I found.

[knightrider]

I've reloaded v3.35 back on and tested it again tonight. It worked well this time around. It cycled between 3 points and settled on the object on the third movement consistently.

Another thing I've noticed, v3.08 wouldn't accept commands from Stellarium after a successful first command. The first time I tried v3.35, it would accept all commands consistently.

It seems that Skywatcher.com has taken down all the previous versions of firmware and only left the current one available for download.