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Jan 20

Dome only rotates for 2 or 3 seconds then stops.



I made some changes to the dome such as installing the shelves in the bay and rotating the dome so the shutter is at 0 degrees when charging and home. I also did some updates and flashed the arduinos. Now when I push to calibrate the dome it only moves for a second or 2 but the driver shows it as still counting up and still seems to think it is rotating. The same thing when I hold the rotate button. It rotates for a second or so then just stops even though I am still holding the button. If I release and repress the button it turns again for the same second or so then stops.

Any Idea as to what might be going on?


Tom Jaeger

Jan 20Edited: Jan 20

Where is your sensor (magnet?) Since you flashed the firmware - I'd do that again and watch carefully to make sure it fully uploads without error. Also verify your motor settings in the driver. Make sure you have the speed, acceleration and steps set with a close guess. 9000, 9000 and 844744 should get you going. Then calibrate for proper steps. Also what software? Some software will require that the mount not be parked.

BTW - I'm Ron Richard in the fb group and on fb


Hi Tom,


After following Ron Kramer's advice..


If you are using the supplied 12V power supply I would suggest the problem is that the silly thing is going into low energy mode and dropping voltage. In ASCOM setup change rotator minimum voltage to something like 0.5V. Personally I got rid of the power supply in favor of something which stays on. In the Automation threads I wrote a lot about this. If you look in Documents\ASCOM at the logs likely the problem is noted there whatever it is.


Good luck!


It was the flash or the PS. I re-flashed it and it still wouldnt rotate from the driver(not sure about the switch) and I saw the volts at 5 and realized the cutoff voltage was 12. I lowered the minimum voltage to 0.1 and it started working.... sorta. The driver seems to have an issue still about not stopping with the mount when the dome and scope are slaved. If i move the scope to the moon and then check the box to slave dome to scope the dome rotates and keeps going. I was watching the driver show the scope, desired dome degrees, and dome physical degrees. It rotates past the scope and past the home and park positions past the scope again and keeps on going.... The driver showing the dome rotating and the physical shutter matching the driver position. After 2 full rotations I stopped it and closed and opened the drivers etc but the issue remained. I am not sure if I did a reboot or not but that will be next.


Tom J

Set the minimim to say 11v or 10.5 the concept is that the shutter will close when the voltage drops below a set level. We'd like it to close BEFORE it's to low to move! Then find it starts raining and can't close because it's at 4.5 volts! If you can't keep power above 11V then change DC adapter. Get one that can output at least 5A. The one that comes with it does. Mine doesn't sleep or reduce power. Non stop... let me think a bit... you have homed and calibrated? must do. What are you rotation steps? I THINK they're around 455800. ish... your homing sensor "IS" working? so when you click HOME it will go there and stop at the sensor? your slave settings are fairly accurate and your first number to slave (dome radius) is 41" ? Start with mount parked and dome HOME. Make sure SLAVE is checked. UNPARK the mount. Slew it say 20 degrees to the east... within 30 seconds the dome should rotate with it and stop with it. (NEAR IT) if you're slave settings need tweaking. Trying to think - of why it would not stop. What software? your mount software needs to let ascom know where it's pointing. Are you using poth? The dome needs to let ascom know where it's rotated to... so that it can be determined where it should stop. I do not use the settings in POTH to slave. I had problems with mine. I use only my SGP settings with slave data. If using SGP - also unpark with SGP (not with mount software). also open the dome and control it via SGP dome control panel. It makes them work together so if the mount has to park the dome will park too. (if that option is checked). If you unpark with mount software then SGP doesn't keep track of the mounts park/unpark status. This is why I say what software? seems like a software issue if you have calibrated and your home sensor works. Now it's a matter of software saying to goto "scope position" and stop - n - track the scopes tracking movments.



Sorry for the delay in responding. I left the voltage for the shutter alone as that is the shutter battery voltage. I changed the rotation voltage to .5 as that is the voltage from the power supply that goes into sleep mode at 5 volts or so.

I will be rebooting everything tonight and looking at it again. The software is totally aware of the orientation of the dome and the scope per the driver. When it passes the magnet for rotation it slows down and recognizes it as home. It just never seems to tell it to stop when it should.

I should know more tonight.


Tom Jaeger

Jan 22Edited: Jan 22


My settings file - you're will be different - but if you start with these it will get you close. You can measure and tweak from there. But since you said you had the Volts set wrong, I'm sharing my settings in case you have the slave settings wrong as well. If your diameter is to high. (like 80) it may likely go round and round since it will go 360 degrees before it finds the scope... if it's looking at a 80" diameter at the equator. Or... the distance across the radius. Diameter at the equator is confusing. It seems like the length measurement around the equator.

Rebooting all the gear fixed the issue of the rotation not stopping at home.


Tom J

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