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Mach3 and G-Rex / (STP/DIR) Manually driving the stepper motors using Raspberry Pi
« on: November 22, 2018, 03:14:52 PM »
I have CNC router along with its driver unit. I dont want to use it as a router, i'm hacking it to move manually using 2 joysticks. One joystick is a 4-way and controls the X and Y axis. The other joystick is a 2-way and controls the Z-axis.
I want to keep my work to a minimum, so i plan to drive the CNC from the parallel port that would usually get signals from the PC (i.e. Mach3). It would appear there are only 3 wires from the parallel port to each of the stepper motor drivers. I assume these are: STEP, DIR & GND?
My question is this:
Assuming that is the only signals I need, what type of waveforms do they need?
From what i've read, DIR is just a standard logic signal (5V or 0V). Is that correct?
It would appear the STEP signal requires a pulsed input? That would make sense.
So assuming it needs a pulsed input, what is the frequency (25kHz)?
Also, what would a typical pulse train look like in order to get the motor moving?
I know the Pi is 3.3V, i have a driver converting them all to 5V.
Any help much appreciated. I'll try post some pics and vids later.
10-4 Rubber Ducky
I want to keep my work to a minimum, so i plan to drive the CNC from the parallel port that would usually get signals from the PC (i.e. Mach3). It would appear there are only 3 wires from the parallel port to each of the stepper motor drivers. I assume these are: STEP, DIR & GND?
My question is this:
Assuming that is the only signals I need, what type of waveforms do they need?
From what i've read, DIR is just a standard logic signal (5V or 0V). Is that correct?
It would appear the STEP signal requires a pulsed input? That would make sense.
So assuming it needs a pulsed input, what is the frequency (25kHz)?
Also, what would a typical pulse train look like in order to get the motor moving?
I know the Pi is 3.3V, i have a driver converting them all to 5V.
Any help much appreciated. I'll try post some pics and vids later.
10-4 Rubber Ducky