let's add acc code!

The developers usually hang out on the IRC or the developers mailing list.

As I understand the trajectory planner changing acceleration on a line by line basis would not be possible with EMC. One could come close by changing the feeds in short increments I assume if this does not break blending...

John

Yep, that would be the place to post that.

John

Presumably the acceleration is currently stored in memory as a variable. It would be possible to move that to shared-memory where it could be a HAL pin.
Linking that value to G-code would not be tidy, but could be done with an analogue output.

In actuality the real problem is that G-code, RS274-NGC is "full", all the 1-letter codes already have a use, and there is no real possibility of making the parser handle 2-letter codes.

(A supplementary issue is that acceleration is per-joint)

It might be possible to add acceleration to your kinematics code. Perhaps by creating an output pin that can be linked (in HAL) to the halui,feed-override.value pin.

Actually, you might even be able to do it with a hal component, that watches the cartesian velocity and adjusts the feed over-ride pin to keep the acceleration correct.

I am not sure how the accelleration gets passed from the INI file to the trajectory planner, but it is possible that you could intercept it on the way and make your own, special, EMC2. It is much easier to do that than to prove that doing so is safe and reliable enough to make it into the main release.

dab77 wrote:

if i were a good programmer i'd modify my emc2, but since i need also a certain grade of reliability i'm not going to modify the code if i don't know what i'm doing...

You can always swap back to a normal version

but..correct me please if i'm wrong: in the .ini file now i'm setting the max accel for each axis, but when i move in world mode the acceleration ramp is derivated from the four max accel,is it right? so, what about changing the four max accel on the fly?

That is what you would need to do, but in your case it is somewhat more complicated as your kinematics are distinctly non-linear.

In any case, the INI file is only read at startup, and the accel values then remain constant.

I really do think that you could do exactly what you want with the motion.adaptive-feed pin and a HAL component, though.

All the developers have access to the forum but don't use it in general as they prefer the IRC and the mailing list.

John