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Last updated: 31 December 2012

This page is for user comments and information specific to the Meade DS, DSX, and some older telescope models. Accessories and Feedback items appropriate to the ETX models are posted on other pages as appropriate. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me for posting. Please use an appropriate Subject Line on your message per the Site Email Etiquette. Thanks. Remember, tips described on this site may invalidate the warranty on your telescope or accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	re: Starfinder Options
Sent:	Saturday, December 29, 2012 12:13:04
From:	richard seymour (
Does your handbox say "Autostar" or "Starfinder" on the bezel around the
IF it says "Autostar", then it is probably operating in Alt/Az mode,
where both motors would be running to track stars across the sky.

Does your handbox have numeric keys? (0->9)
If it does NOT, then it's a "494".
If it DOES have numeric keys, then it's a 495 or 497, and there's hope...

If it's a 494 (saying "Autostar" around the display, then reading the
downloadable manual for (for example) an ETX-60  would reveal the menus
and options available.

Unfortunately, the 494 does not have GEM programming, desirable for
flipping the telescope end-for-end as it crosses the meridian, to
prevent running into the tripod.
At best, you could choose a model (Setup/Telescope/Telescope Model) to ETX-60 or ETX-90,
and then change the Mount to "Polar"  (Setup/Telescope/Telescope Mount) ...
that should stop the DEC drive from operating during sidereal tracking.

The handbox-to-telescope protocol has been somewhat reverse-engineered,
most of the findings are published in the Files area of the "Roboscope"
Yahoo group:
Very few people have successfully emulated it.. .it's much much
easier/faster to simply buy (on eBay, etc) a 497 Autostar, which knows
how to run GEM drives (any LXD model), and/or which can have its
firmware "patched" to "know" the 4504.
(the patch kits are available on Mike's site under the Autostar Info page)

On the other hand, there's always the attraction of attacking the
problem as a hobby, where the realities of hours invested (doing it
yourself) against simple cost (buying a 497) don't apply.

good luck

And more:

Hi... (continued)

I see (by re-reading your final paragraph) that you do have the non-numeric keypad
(it's the only model with a glued case and no second "port")

When you're searching ebay (etc), you could also use a "495"... they're
the same full keypad as a 497, and can be reloaded with full 497 handbox

Although rare(r) as time goes by, 497's (without scopes) do appear on
the lists.
You can also use the newer 497EP and Audiostar.  (do not try to load 497
firmware or patches into those models... seek out the appropriate
firmware and patch kits)

good luck


From:	Anthony Tonizzo (
There is more than just the mental challenge of doing it yourself.

I do not see why I have to learn how to use new devices (the Starfinder
in this case, but the same can be said for a variety of other cases)
where the interface is simply awful and requires a steep learning curve
that cannot be leveraged anywhere else.

I am a fan of good interfaces, and today everybody has a smart phone in
his pocket that is more than capable of doing all the Starfinder does
and then some (care to compare the dual 1GHz 32 bit ARM inside any
Android phone with the 6811 in the Starfinder? :)

If the HBX protocol is known then programming a smart phone to do all
the pointing and driving would not be too difficult. Astronomy is a
hobby that attracts highly resourceful people more often than not with
good programming skills. Crowdsourcing of an open source codebase would
do the rest.

Just random thoughts.

Mike here: Actually, there is an excellent iOS and Android app that can control many telescopes via Wi-Fi or RS-232 serial wire. It is called SkySafari. You can read my reviews on the Accessory Reviews: Software page.


What usually happens is that folks write applications (such as
SkySafari) which make good use of the smartphone's power and toolkit...
and still leave the actual GoTo fine control (and relatively tight servo
loops) to the Autostar.

The 6811 may be an "almost obsolete" processor (hence Meade's move to
the Toshiba TMP92CM22FG in the 497EP and the Audiostar), but it's quite
happily running a real-time multi-threaded "operating system" in there. 
Primary thread clock is at 4096 Hz.
(although in some ways the multi-threading makes the code highly
inefficient (tons of stack activity to handle the threading), it does
amazingly well).

Back in 1983 or so, Motorola and WindRiver got together to create
"OS-9", a port of Unix that ran on the M68C11's predecessor, the M6809,
in only 64KB of ram.
(i ran mine on a Radio Shack Color Computer... the existence of which
saved me from building my own system from parts).  ((no, the Autostar is
not running OS-9))

There are a few "open source" telescope control systems out there (Mel
Bartels', for example), but most of them stop at the simplest of human
interfaces (some method of alignment, plus entry of RA and DEC for
GoTo).  Beyond that, they expect you to hook on a PC.
For Linux-based scope control, there's INDI:

For higher-level planetarium operations (like SkySafari) there's Cartes
du Ciel ... but it's PC-based, not smartphone.

I certainly don't want to discourage you from giving it a shot... your
"product" would be applicable to any of the Meade Autostarred scopes. 
Folks are also fitting 497 Autostars and a 3rd party motor control card
into Classic LX-200 scopes, too...
(there's a case where the modifiers are making the motor-side emulate
the Autostar protocol, and using the 497 as their user interface).

I'm certainly happy to kibitz along the way

have fun
Mike here: I keep hoping for an iOS app that mimics the AutoStar (#497 and II) handcontroller without the planetarium extras. I love my Meade Wireless AutoStar II but since it has been discontinued, I worry about the day (or night) it dies. Using a smartphone to replace the functionality of the handcontroller would be SO convenient!


Mike, the AS II handbox is a completely different beastie than the 497.
The "497" functions are inside the LX200gps base.

That said, Gene Nolan (inventor of the 506/909 replacement) has created
an iPhone app to replace the AS II's wireless handbox...

As he posted to the LX200gps group:
Quick video of an IOS app talking via a wifi to rs232 adapter plugged
into hbx port of an lx200gps. The app and adapter replace the hbx.

Many thanks to Andrew J for providing a spare semi-broken lx200gps
control panel and all the insight into the HBX serial protocol.

... unfortunately for Anthony, this replaces the dumb-terminal handbox
on an LX200GPS, not the "computer inside" 497 handbox.  (Gene's uses a
far simpler protocol)

Gene is now trying to go through Apple's hoops of getting it accepted by
the App Store.

have fun
Mike here: I saw his message on the LX200GPS group. Wish him luck! I'll have to check it out once it becomes available.


Thinking about the stuff discussed in this thread helped me understand
what I _really_ want: An end-to-end program that runs on a smart phone
to drive any type of telescope.

It sounds far more complex than it really is. Layered software stacks
are nothing new (TCP/IP anyone?) In this scenario the stack is divided
in layers, each handling one part of the transaction that goes from the
planetarium down to raw motor driving.

You want to drive a Dobsonian? Compile/enable the right layer and you
are all set. HBX? There is a layer for that too. One layer handles the
coordinate calculation, one layer handles the communication with the
user (layers can be written that go from planetarium to a simple keypad
or RS-232.)

It would be a fun project to work on as soon as I am done with the
debugger I am working on now (which, interestingly, is itself based on a
heavily layered architecture.)



Many of the layers already exist...
SkySafari (and i think there's a version of Voyager, and others for
Android and Palm) is an example of one that's already "soup to nuts",
with the ability to talk to some existing scope controllers (such as the

Note the word "some"

Unfortunately, the mount manufacturers have not agreed on a common protocol.
Many have at least a partial emulation of the basic Meade LX200 protocol
(so  :SrHH:MM:SS#   will set the RA of the target to HH:MM:SS )
..but many have not (Celestron, for example, differs)

If you wish to bypass the Autostar, you're getting far more "atomic".

The Meade motor cards expect a  floating point *speed* command.
They're not told a distance or an "alt/az" value... just speed.
Their internal servo system then maintains that speed fairly accurately
(they deliver PWM to the motors, and use a quadrature encoder to keep track of the speed).
The motor cards do not know the relationship between their speed and the
actual angular motion of the telescope itself... that "loop closure" is
performed by the Autostar.
The dynamic range of the motor control is surprisingly large... in the
ETX-90 it's from about 12,000 rpm down to about 50 rpm.

Some systems (such as Mel Bartels, and some commercial scopes) use stepper motors.
The Celestrons, like the Meade, use DC analog motors.

Meade has patents on the idea of distributed control.. (and the patents
discuss the signals 'twixt the Autostar and the motor cards).
and look at patents 6,304,376  6,392,799  6,445,498   6,563,636  align: 6,922,283
7339731, 7221527, 7092156, 7079317, 7053992, 7414707, 7227223

Meade's published serial protocol (for PC to Autostar) is here:

Stellarium is another example of an open source planetarium and telescope control program.
It knows a few scope protocols, and has a method for invoking the ASCOM
initiative's work for doing a broader range (but ASCOM is woefully
Windows-only, even though Stellarium is multi-platform).  INDI is a
Linux ASCOM-like project for layering the scope-protocol-specific duties.

> It would be a fun project to work on as soon as I am done with the
> debugger I am working on now (which, interestingly, is itself based on
> a heavily layered architecture.)

Welcome to the can of worms of dynamic scope control...

have fun
Mike here: SkySafari 3 Pro (as well as the "Plus" version) can probably control the most different types of GOTO telescopes. See the Southern Stars web site ( for the list. I use the Pro version, and have controlled my ETX and LX200-ACF telescopes using it.

Subject:	Starfinder Options
Sent:	Wednesday, December 26, 2012 14:23:46
From:	Anthony Tonizzo (
A few years ago I bought a Meade 4504 for $20. When I finally found time
to work on it, a quick check on a Ronchi tester showed a bad case of
turned edge on the 4.5" mirror so I re-polished and re-figured it and I
am now in the process of rebuilding the unit (Jupiter looks spectacular
even without the aluminum coating on the mirror.)

One thing I found is that the StarFinder controller that came with the
telescope does not seem to have the same options as those described in
the PDF file available online for the 4504. To add to the misery, the
user interface of the controller is so bad that, without a proper
manual, I cannot seem to be able to guess how to use it. As much as I
try, things do not just make sense, with motors that move when they
should not, stay put when they should move and generally do not give
enough feedback to know what is going on.

My first reaction was to rewrite the whole thing for a small
microcontroller. It would not be difficult to do but while reading your
site I learned to my dismay that the HBX protocol has not been reverse
engineered yet, and my software would hinge on knowing the exact
messages used to move the motors.

Plan B now revolves around trying to replace the existing handheld
controller with a newer model, perhaps one with instructions I can
actually follow. Ideally the two motors in the telescope would no need
to be replaced. The one I have does not have any "upload" connector, and
it seems a sealed device that is not meant to be cracked open: Obviously
it is an older model, likely late 90s or early 2000s.

Do you know if there is any market out there for these controllers and
if so, where I could score one? I checked e-Bay and Craigslist, but the
controllers available are always sold with the scope they are connected

Any help would be greatly appreciated.
Thanks much!
Anthony Tonizzo
Mike here: If you search the ETX Site for "4504" you will get lots of hits, some of which might be useful to you. You could also check out the Meade 4504 Yahoo Group (

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