Doh!  I just found this sensor which completely eliminates the need for the Arduino.  This provides a stand alone solution for registration mark detection.  Now we can just work on the VB!  This should be easy to wire in as a probe.  Does anyone have some examples of calculating an arc tan in VB and setting the G68 coordinate system rotation from a script?

ATN (arc tangent) is covered in the "Cypress Enable for Mach" manual , page 44

How would i then set the g68?

I'd  provided how to set the g68 in the file that was posted to your other thread.
http://www.machsupport.com/forum/index.php/topic,26758.msg189574.html#msg189574

Call SetOemDro (118,NewAngle)
OEMDRO was added to screen with machscreen. To show me what it was set too. As if it is anything other than zero the Axis X Y DRO's values turn red.

The sensor you used before does not need the Arduino to work, it just needed a 12 volt DC supply, as it incorporated a SPDT relay.
You could then provided the 5 volt source at the relay.
Though it does a poor job of detecting a thin line and lighting the area has to be extremely controlled to be accurate and repeatable.

Using a wide line to get it to work well, makes me suspect its precision at the ability to find the true corner of the scanned probing routine.

i made a camera that finds the registration marks and adjusts for distortion and rotation

Hi guys! Any news on this? Does anyone have a registration system up and running?

because it was for my work and i spent work time i can not give a lot of information.
attached is the script i used for finding the dots and rotating and stretching the file.
hope it is a help

Thank you! I really appreciate it! :-)

Judging from your post, this solution that my team and I have been working on probably fits your criteria: https://www.youtube.com/watch?v=dqFpI4t21Z8

Effectively, we use registration marks to re-align the generated G-code, allowing for a proper cut despite the material being rotated or distorted. Let me know if you have any questions, I'd be happy to chat about this feature.