Focuser for Canon 200mm F2.8 lens with Canon 1000d camera

[Paulkirk]

Hi, I would like to make a focuser for the canon 200mm f2.8 lens. I have an easydriver board and a bipolar stepper I rescued from somewhere. I had it all working as a focuser on the lens some years ago with a project called SGL observatory automation, but I think that's now no longer supported. So I'd like to use the myfocuser project. Could you give me some pointers as to how to proceed? I've attached a photo of the setup in case it helps.
thank you for help,
Paul Kirk

[Paulkirk]

Just to add, it is currently using an Arduino nano to drive the stepper.

[brownrb]

Hi Paul
What is the driver chip you are using to drive the stepper motor - Easydriver.

What are the pins used by the arduino to connect to what pins on the Easydriver?

Once we know that it is a simple matter of changing a few things.
Let me know and I will send you a firmware file to use with your focuser,

regards
Robert

[Paulkirk]

Thanks Robert, I'll take the arduino and easydriver out of its box and check. I'll post again soon.
best wishes
Paul

[Paulkirk]

Hello Robert,

My apols, it's a K179 stepper driver board.

Arduino Uno pin 2 -> Direction
Arduino Uno pin 3 -> Step

many thanks,
Paul

[brownrb]

Hi Paul
This is a cut down version, no display, no probe, fixed step mode, etc
should work
You might have to adjust in myboards.h these values to get the speed you want

#define EASYDRIVERFAST          4500     // delays for motorspeed
#define EASYDRIVERMED           8000
#define EASYDRIVERSLOW          12000

[brownrb]

lower value = faster
higher value = slower speed
minimum value = 1000
maximum value = 13000

If speed is FAST then change EASYDRIVERFAST value
How to do this with Windows app
Connect to focuscontroller
Set motor speed to fast
try move +500
if you want to alter speed setting for fast
use menu option Motor-Speed- Setmotorspeeddelay
It will display current value - continue to form where you can alter it
If motor too slow, reduce by 100. Click set to save setting
try motor speed again
if ok repeat process for medium and then again for slow
if not okay repeat adjusting value by around 100-200 steps at a time

At the end of this you should have new values for Fast, Medium and Slow
Write these down
exit windows app

Goto the firmware and enter these new values into myboards.h

#define EASYDRIVERFAST          3400     // delays for motorspeed
#define EASYDRIVERMED           7200
#define EASYDRIVERSLOW          11100

then reprogram the controller

[Paulkirk]

Thanks for this Robert, when I extract all, I saw the easydriver.ino Is this compatible with the driver board I have - the K179?

Also how do I get to a user interface please?

Paul

[brownrb]

Obviously you would use an arduino , and connect the
Arduino Uno pin 2 -> Direction
Arduino Uno pin 3 -> Step

and then you would use the arduino IDE to programer the Uno with the firmware I gave you.
Have you had any experience with programming an Arduino Device?
Follow the instructions in the PDf about programming the Arduino using the Arduino IDE and also installing the required libraries.

Once you did that, then you could use the windows application here to control the focuser.

[Paulkirk]

Thanks Robert, yes I've programmed arduino and written an ASCOM dome driver, just wondering where in the files section is the UI programme, there seem to be a few diferent ones.

thanks
Paul

[brownrb]

https://sourceforge.net/projects/arduinoascomfocuserpro2diy/files/WINDOWS/

either of those should work

[Paulkirk]

Thanks Robert, I'll give it a try in the next week or so.
best wishes
Paul