Wired Canon EF/EF-S lens adaptor for ASI294 camera.

[chemistorge]

Hi All, 

 

My new project is a DIY version of this product. I have focus/aperture by wire lens for my Canon camera and I would like to use my ASI294mc with them especially  my 50 mm, 24 mm primes and  also my 250 mm zoom lens. 

I started with the following 3d printed adaptor (here) as a base. I modified it to enable pogo pins to fit and make contact with the pads on the lens.  I am now waiting for the small circuit board to adapt the pogo pins to a 2.54 mm header for ease of connection. 

Once I receive the circuit board I will be able to start writing the arduino code to interface with the lens. I have found the protocol online. As I teach arduino programming to students at a college, the program should be no problem. 

 

I plan the following specs:

1) Works with EF and EF-S (currently 3d model only fits EF as I need to chop a bit off.)

2) Be able to set aperture with two buttons, setting to be displayed on 0.9 inch LCD screen.

3) Be able to focus: 1 button for near focus, one for infinite focus, +/- 10 steps, +/- 1 step. (possibly include a routine that works out how many steps from near to far focus and then display on screen to enable more precise refocusing in subsequent sessions). 

I will update this page as  I progress. The adaptor will fit all astrocams with 17.5 mm back focus.

 

[chemistorge]

Finally managed to have time to progress this project. 

So far: 

1) Figured out the protocol and code to send commands and parse replies. 

2) I can adjust aperture and focus.

3) Implemented routine to find current focus position.

4) Implemented routine to move focus steps +/-.

5) Implemented routine to find total number of focus steps.

 

On the lens I am using the focus motor is not that precise.

 

Edited October 31, 2021 by chemistorge

[dmki]

Really nice work!

[kbrown]

Great job. Are you planning to release your work to the public? Been thinking of doing something similar every now and then...

[chemistorge]

Hi There, 

 

Sorry for the long time for a reply, work, christmas and Covid has got in the way.

 

I have wrote the basics of a arduino library for accessing EF and EFS lens. I have also wrote a sketch that can communicate with Ekos via the Myfocuser2 protocol, it allows you to do the autofocus routine with a canon lens.

 

I have attached the current files for your enjoyment!!!

 

Canonef.cpp Canonef.h main.cpp