Automation, sensing and robotics • Re: 4 Stepper simultaneously with Pi 4 for a (sort of) CNC

Hi there, sorry, I had to pause my project for a while but I'm getting back to it.

Current situation:
I was able to get my machine running using the Pi to map Joystick data to a frequency that the Pico receives via USB. The Pico simply generates a PWM with the given frequency and a fixed puls duration. He also toggles the DIR Pins.

Apart from a problem of lack I have in the software that appears at times, the system functions as intended.

Now:

With this setup it should be easily to move from PWM to grblHAT on pico and receiving gcode from Pi. On Pi, the joystick control could - in a program - update target positions which from time to time are sent as gcode to pico. Update rates 50 to 100ms.

I find that to be a pretty good Idea and thought about that a bit. I like the Idea of updating a virtual position value in the Pi and sending it in form of of G-Code to the Pico running grblHAT.
My only concern is that I'll get unsteady movement since grbl advertises that the software looks a few commands ahead to calculate a smooth trajectory and I give the command's only the instant my Pi calculates them.


Merlin : )

Statistics: Posted by MoerlinD — Wed Feb 07, 2024 9:40 am

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