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Soundstepper Alt/Az scope control???

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#1 gpelf

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Posted 24 January 2013 - 11:45 AM

Was curious if anyone has built and tried this system????

Soundstepper

#2 Geo.

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Posted 25 January 2013 - 12:59 PM

There was some discussion about it on the Yahoo Roboscope group a while ago. Don't know if anyone pursued it.

#3 Tavi

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Posted 27 January 2013 - 08:43 AM

It sounds good! :) Maybe someone can do the trick with only one usb 5+1 channel sound board? :)

#4 polaraligned

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Posted 27 January 2013 - 09:32 AM

I never liked stepper motors for high power viewing. Servos are a lot smoother.

#5 Nils Olof Carlin

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Posted 27 January 2013 - 03:59 PM

I never liked stepper motors for high power viewing. Servos are a lot smoother.



De gustibus non disputandum.
But the point with the link in the OP is to drive steppers smoothly - whatever you have used was apparently not suitable for the job.
Vibration-free driving of stepper motors is perfectly feasible - the soundstepper is one way, I have used others.

Nils Olof

#6 gpelf

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Posted 28 January 2013 - 03:30 PM

Thanks guys,

I think I will give it a go, I already have all the components except for the USB devices. I like the fact that the current limiting can be obtained with just changing the value of the 1ohm load resistor and the software looks nice as well.

Clear Skies,
Greg

#7 ccs_hello

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Posted 28 January 2013 - 07:13 PM

At one time, I was considering that seriously. I did find out that the DMOS type of USB audio dongle is out and nowhere to be found. The thing that flood the market nowadays is the other type.

I stopped pursue this project for multiple reasons:
1) a PC as the main processing core is needed thus cannot afford not giving the process enough CPU time. I'd rather go for embedded solution and be done with it.
2) Ever guess if the program freezes/stuck and the USB audio is sending a fixed value out? If very unlucky, the expensive stepper will be a constant DC drive at full power for a long, long time. In the mean time, you are sitting there enjoy the sky...

I'd say that the developer put a lot of effort in it and I'd appreciate that. Independent of my own choice.

My 0.02

Clear Skies!

ccs_hello

#8 gpelf

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Posted 28 January 2013 - 09:20 PM

ccs hello,

Thanks for the input,

According to the authors article the reason he is using this mode is that it uses a very small amount of CPU power, I have a laptop with a 1.8ghz processor and 500mb of RAM (yea, I know I need to upgrade bad) I used a digital O-Scope at work and monitored the pulses from the soundstepper software while playing in Stellarium (It goes super slow and locks up quite a bit due to the low amount of memory) After 10min. I went back and viewed the pulse train and it never missed a beat, I was impressed....
As far as the constant DC out, that is covered as well if the pulse train should stop the 2 470 ohm resistors fro the input pins to gnd and +12v sets the output to 0v,,,,
I am not at all saying it will work the way I am wishing for, I just dont know yet. I finished most of the circuit today and hope to play with it some this weekend :shrug: :shrug:

Clear skies,
Greg






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