Upgrade to 2.5 with 5i20, ncggui and joypad

Generally speaking if I have a machine that is working great I don't change or upgrade it unless I am involved in testing. After all "If it ain't broken don't fix it"
A few years ago I set up a mill with steppers, the Mesa 5i20, 7i47-s and 7i37. It has worked flawlessly so I left it alone running 8.04 and emc2 2.4.
LinuxCNC 2.5 now has some new features and it was time for a new hard drive so time to upgrade...

If you follow the Wiki instructions it should go pretty smooth.

The following hiccups of going from 2.4 to 2.5 are posted elsewhere but it may be a good idea to point some of them out all in one spot.

These are some that I ran into...

As per the Wiki you may need to rename directories and or file locations and shortcuts to take into account the name change.

If you are using a usb joypad you may need to rename the pin
input.0.btn-trigger
to
input.0.btn-joystick .

If you are using NGCGUI you will need to edit your configuration file to remove the line
USER_COMMAND_FILE = ./tkapp.py
as the 2.5 version does not use it.

Skip any of the steps above that apply and Linuxcnc will not start.

Having done that the machine immediately reported a joint following error.

This was the case in earlier versions if you had a Base thread on a stepper system but did not use the Base thread. Easy solution was to remove the Base thread from the configuration and all was well.
Other solution was to increase the
stepgen maxaccel for each axis from 0 to perhaps 2 to 4 times the axis acceleration.

The first solution does not seem to be the case in 2.5, even without a Base thread the joint error occurred.

The second solution does however seem to work, on an axis with MAX_ACCELERATION = 8.0

When I edited my configuration from

setp hm2_5i20.0.stepgen.nn.maxaccel 0
to
setp hm2_5i20.0.stepgen.nn.maxaccel 16
(2x the MAX_ACCELERATION)

It took care of the errors.

Now the mill is up and running again.

I just looked and if your configuration is generated by the current 2.5 version of Pncconf it will set the stegen maxaccel at least 1.25 times the MAX_ACCELERATION automatically, so new configurations will probably be fine.

Rick G