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Author Topic: Side Real with LV8729 driver  (Read 50 times)

kaito83

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Side Real with LV8729 driver
« on: January 22, 2021, 11:32:49 »

Dear Tom,

I recently changed to LV8729 drivers, unfortunately the bad whether I cannot test the equipment, but It's look like the sidereal is quarter of the normal.
The driver specs same as the drv8825 the 1/32 (High   Low   High) and 1/4 (Low   High   Low ).
The goto positioning is OK when I tells to the mount goes to DEC90 to 0 is fine same as RA, with hours, but I switch to sidereal it moves quarter.
example Sidereal start from 0 RA after 1 hours its reach only 0/quarter point.
I have to modify the firmware or what I'm doing wrong or is this just a mistake by myself?

Regards Tamas
« Last Edit: January 23, 2021, 22:32:52 by kaito83 »
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kaito83

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Re: Side Real with LV8729 driver
« Reply #1 on: January 22, 2021, 14:47:00 »

I Found the code
                case 32:
                    // 1/32
                    modeState[SPEEDNORM] = (( HIGH << MODE2) | ( HIGH << MODE1) | ( HIGH << MODE0));
                    // 1/4
                    modeState[SPEEDFAST] = ((  LOW << MODE2) | ( HIGH << MODE1) | (  LOW << MODE0));
                    break;

Dear Tom,

Could You fix your DRV8825 code to this
modeState[SPEEDNORM] = (( HIGH << MODE2) | ( LOW<< MODE1) | ( HIGH << MODE0));

permanently because DRV8825 is also operate in HLH in 1/32.
In the future will be compatible with LV8729 and stepper is very smooth like DC motors.

Best Regards Tamas
« Last Edit: January 23, 2021, 22:33:42 by kaito83 »
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kaito83

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Re: Side Real with LV8729 driver
« Reply #2 on: January 23, 2021, 22:24:10 »

Problem solved with the modified code, the sidereal is precise now.
And I recommend everybody the LV8729 driver and stepper motor smooth like a DC motor after this change.
I also uploaded the modified hex.
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