Guys,

I could need some some help and advice in upgrading my telescope to a
servo controlled unit. My problems in brief.
Two years ago I've obtained a heavy German Equatorial Mounting with a
12.5 inch Newton telescope. Though the 15 inch worm wheels on both axes
are stepper motor driven, the electronics can not handle computer
control, they don't have microstepping and the slew-rate is to low,
about 0.5 degr/sec. and very loud in the middle of the night, so this
setup is a dead-end street.
I decided to go looking for a servo-motor solution, but I couldn't find
a do-it-you're-self project on the internet and the commercially
available systems were to expensive. I talked about my problems to a guy
who is working on the very nearby radio telescope WSRT (Westerbork
Synthesis Radio Telescope)( at the moment they are looking for the Mars
lander), and he told me they were updating the motor control electronics
on all the 14 telescopes. I tried to persuade him to give me the spare
set of electronics they had, but he refused, however they had
experimented in the past with a system based on the LM628
(National Semiconductor's Precision Motion Control chip with build in
programmable digital PID filter), but had to abandon this after they
found out how "noisy" it was in the radio-spectrum.
I became quite interested in this setup and after I received all the
documentation they had (but no software, they hadn't reached that stage
yet), I started building it. But after a few weeks I realized that I
might could get the electronic hardware working but without the
software............! I know very little about programming, and I'm very
puzzled about the hardware/software interface I need to translate the
LX200 protocol into commands the LM628 will understand. Would it be wise
to build a microcontroller to do the job or should I go for a software
solution? What are the pros and the cons? Is there someone on the net
who dealt with this problem before or had a similar experience?
So I stopped building and hoped I would find a project based on the
LM628 with the matching software, in the near future. Due to
circumstances it took me a lot longer, but since a few weeks I'm roaming
the Internet again looking for some suggestions and ideas.
I know for sure there are some professional observatories using the
LM628 to control their telescopes so I wouldn't wonder if there are one
or two amateurs using it too or are planning it to use!

I hope some of you have some good news for me!

With kind regards,

Albert



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Albert Schuitema
Dwingeloo 52 50' 18,6" N
The Netherlands 05 22' 26,3" E
alberts@...
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