Index homing Mesa 7i96s

But it is doable without needing custom fw on the mesa?
editing the hal file is not an issue for me. Other than figuring out what needs to be changed.

It needs custom firmware or a specific component that simulates index behaviour
I think there is a thread where this was discussed, searching for stepgen index might find it

The disadvantage of using a component to simulate index behavior is that it
will typically miss index pulses shorter than 1 servo thread in length.

I don't mind making special firmware for this if you can live with the loss of 4 isolated inputs

I have a few friends that also need this. When doing index homing the velocity is very low so i dont think missing the pulse is an issue. That would be amazing!

Out of interest, what makes this method so slow? I assume that the "proper" encoder method responses faster?

If you use the stepgen + index firmware, it works identically to homing to index
with an encoder and can detect short index pulses (sub microsecond)

If you use a special component to do this, it will be limited to detecting pulses
longer than 1 servo thread period.

Here is a link to a thread with a users hal component that implements stepgen homing to
index:

forum.linuxcnc.org/24-hal-components/463...der-m19-g33-1#246815
 

most likely I'll just by an expansion board to keep it simple. For the 100 bucks or so it is not worth making a super custom config. Thank you anyway!

Here is firmware for a 7I96S + 7I85 (not 7I85S) with stepgen index:

 

The 7I85 encoder index inputs can be stepgen or encoder indexes