Custom homing - distance coded glass scales

Hello

(Third try posting this, there's something wrong with the forum server)

I'm retrofitting a Cincinnati Arrow which does not have any kind of homing or limit switches on x and y -axis. Glass scales have distance coded index marks though and I would like to use them for homing. I found one successful attempt doing so: 
forum.linuxcnc.org/12-milling/42195-retr...ing-success?start=50

Editing hm2 similarly shouldn't be too difficult but homing.c looks completely different nowadays. Should this kind of thing be done with homecomp? Any advice on that would be welcome, my coding skills are slightly limited and there is not too many examples of homecomp yet.

Thanks
Ossi

Homing on glass scale index is supported directly by Linuxcnc and Mesa's products.
linuxcnc.org/docs/html/config/ini-homing.html#_home_use_index but the whole page is worthwhile reading.

Yes of course but distance coded indexes are not as far as I know? (The distance between index marks varies and the distance is used to calculate absolute position)

My linear scales have index every 50 mm and that works.
That's not really what you are looking for I now understand.
 

I got it working with help of a coder brother and vscode agent by editing mwinterm 's homing files. There were several problems at start which caused inaccuracies in both encoder latched position and home position calculation but now it looks to be accurate. I uploaded quick video of the startup and homing if anyone is interested: www.youtube.com/shorts/St_XhQs68xQ . I also added some nice features;
-the machine offsets are stored within every 2 seconds and those offsets are used as machine offsets at startup before homing, so its kinda like absolute encoders but of course need to be homed to verify position
-custom .py -file checks soft limits before homing and aborts if current position is too close to limit
-also managed to remove homing final move, so minimal amount of movements in homing.

I'm considering if I should share the changed files or not, they are so machine specific. Maybe later when I find out if it's reliable and safe.

Regards
Ossi