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Author Topic: Question about error "IVal must be <1200"  (Read 2586 times)

newil86

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Question about error "IVal must be <1200"
« on: February 08, 2018, 06:40:53 »
Hello! I have a DIY Astroeq based on Arduino Mega. Motor Nema 17 1.8' and A4988 drivers. Gear ratio = 2. My mount is EQ3-2. When i try to upload config i get an error 'Ival must be <1200' on DEC (my calculated value is ~1380). I can not understand what this limitation. I edited this value to 1400 and build the projects (firmware and UI). After that I was able to load the configuration.
What will affect IVal >1200 on DEC?
Thanks
P.S. Sorry for my bad English...
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TCWORLD

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Re: Question about error "IVal must be <1200"
« Reply #1 on: February 08, 2018, 08:05:09 »
IVal too large means that your overall gear ratio is much too small.

The 1200 limit is intentional to prevent issues with performing low speed movements, and to allow the acceleration/deceleration tables to work correctly. Values larger that this can result in unintended overflows in some calculations.

Additionally if you are on the high end of IVal, it means the resolution of the mount is going to be very poor - the DEC axis will move about 3 arcseconds each microstep.
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Tom Carpenter (AstroEQ)

newil86

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Re: Question about error "IVal must be <1200"
« Reply #2 on: February 08, 2018, 08:59:24 »
Quote from: TCWORLD on February 08, 2018, 08:05:09
Additionally if you are on the high end of IVal, it means the resolution of the mount is going to be very poor - the DEC axis will move about 3 arcseconds each microstep.

Many thanks!
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TCWORLD

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Re: Question about error "IVal must be <1200"
« Reply #3 on: February 11, 2018, 15:04:28 »
Hi,

I found a glitch in the config utility which was causing the issue - one of the calculations was iterating too far causing it to ignore perfectly usable IVal options.

I've attached a patched version of the config utility (firmware is unchanged). This is now fixed in the release version from the downloads page.

Hopefully it should no longer produce the error.

Kind Regards,
Tom.
« Last Edit: March 05, 2018, 08:01:32 by TCWORLD »
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Tom Carpenter (AstroEQ)

newil86

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Re: Question about error "IVal must be <1200"
« Reply #4 on: February 14, 2018, 06:49:01 »
Quote from: TCWORLD on February 11, 2018, 15:04:28
Hi,

I found a glitch in the config utility which was causing the issue - one of the calculations was iterating too far causing it to ignore perfectly usable IVal options.

I've attached a patched version of the config utility (firmware is unchanged).

Hopefully it should no longer produce the error.

Kind Regards,
Tom.

Hello,

Thanks!!! Today i'll be testing this version.
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newil86

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Re: Question about error "IVal must be <1200"
« Reply #5 on: February 18, 2018, 11:18:10 »


Hello,

Thanks!!! Today i'll be testing this version.
[/quote]

To many thanks! It's work!
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pterodyne

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Re: Question about error "IVal must be <1200"
« Reply #6 on: March 05, 2018, 05:16:32 »
should we be using the version above? or the version on the website? It wasn't clear if the patch here has been put back to the downloaded version of 8.11
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TCWORLD

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Re: Question about error "IVal must be <1200"
« Reply #7 on: March 05, 2018, 08:01:01 »
It was only a minor change to the config utility, and has already been pushed to the downloads page.

The firmware (v 8.11) is unchanged.
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Tom Carpenter (AstroEQ)