Vixen MT1 motors

[N-DD]

Hi,

would AstroEQ work with Vixen MT1 motors on a Vixen GP mount? The motors are 6-wires unipolar steppers, so I guess it is possible to use them as bipolar, and they have a 1:120 geared reduction (the mount's worm gear ratio is 1:144). Can AstroEQ do half- or quarter-stepping? Using 16x micro stepping might not work with these motors, as the torque they can generate isn't very high (around 30-40 mN*m) and might stall the stepper.

Thanks,

Nico

[TCWORLD]

AstroEQ does 1/4 stepping if you select 'Microstepping Disabled' from the configuration utility.

You can wire them as Bipolar, but you will likely find that the maximum speed you can achieve is reduced. With such high gear ratios, you are already looking at <50x the sidereal rate max speed before they stall.

[N-DD]

Hi again,

I am using an arduino mega 2560 but I could not manage to communicate with the board to upload and configure the system using the configuration utility. However, by first uploading AstroEQ.ino to the board and then running the configuration utility everything went ok. BTW, I had to change line 34 of EEPROMReader.cpp

return eeprom_update_byte((byte*) address, val);

to

eeprom_write_byte((byte*) address, val);

otherwise the scheme won't compile.
Since I am fairly new to arduino, I was wondering wether I am doing anything wrong: is the configuration utility supposed to work with an arduino mega without uploading the sketch first?

Also, do I have to set the correct parameters from the EQMOD panel (steps per worm revolution, etc.), even if I configured them previously using the config utility?

Thanks,

Nico

[TCWORLD]

Hi Nico,

The config utility has an upload firmware button which should be able to upload the firmware to the Arduino Mega without having the Arduino IDE.

You don't have to set anything in EQMOD, it will read the mount configuration from the AstroEQ controller.

Regards,
Tom.

(Apologies about the problem compiling, I uploaded the wrong version of the file. That is fixed now.)

[N-DD]

Hi Tom,

thanks. I will try again with the config utility. Strangely, on my system EQMOD isn't able to get the mount configuration. Also, I had to disable the "reset on connect" (110 ohm resistor between 5V and RESET pin on arduino) in order to be able to connect to EQMOD: are maybe those two issues related?

Thanks,

Nico

[TCWORLD]

Found out why it wasn't uploading the firmware, it was using the wrong upload string as I removed an entry from the boards dropdown but forgot to remove it from an array of upload strings.

[N-DD]

Ok, the config utility works now, thanks. However, in the ASCOM properties panel the mount has still the default gear ratios, and not the one I configured using the utility. Do I need to change those properties selecting "custom mount", or AstroEQ will move the RA axis at the right speed? (Sorry but I still didn't have any chance of trying it under the sky!)

[TCWORLD]

It doesn't matter what is in that properties panel, EQMOD will read the configuration when it loads and use what it reads.