origin of ground in a stepper motor system

Hello everyone!

In my system im controling stepper motor with arduino leonardo that connected to a PC.

Im wondering where i should take the DC ground for the arduino and the motor driver.

Do i take it from the inputs of the power supply (24V output) or from the arduino board (that gets power and data from PC with USB cable)?

Attached a schematic of the system.

Many thanks!

Image from Original Post so we don't have to download it. See Image Guide

...R

What stepper driver are you using?

With the Pololu A4988 drivers that I use there is no need to connect the power supply GND to the Arduino GND - it must happen inside the A4988 board.

...R

Thanks for the image info!

Robin2:
What stepper driver are you using?

With the Pololu A4988 drivers that I use there is no need to connect the power supply GND to the Arduino GND - it must happen inside the A4988 board.

...R

im using the stepper motor and driver from this kit

In this video he using the same motor and driver, but he gets the ground from a different source which
im not using in my system.

Such a motor driver has opto-isolated inputs - you need to run two wires for step and two wires
for direction, the relevant signal and its ground return in each case. Consult the documentation
for the motor driver of course (you did this?). Since the motor driver is opto isolated there
should be no connection between motor supply and arduino at all.

Your guy in the video is connecting 5V to Pul+, Dir+, and EN+. If you look closely you can see the red wire loops between those pins. The Pul- and Dir- are then pulled low to step or change direction, and it doesn't look like he connected anything to disable the drivers.

This is also documented on your eBay page if you just scroll down a bit.

Chagrin:
Your guy in the video is connecting 5V to Pul+, Dir+, and EN+. If you look closely you can see the red wire loops between those pins. The Pul- and Dir- are then pulled low to step or change direction, and it doesn't look like he connected anything to disable the drivers.

This is also documented on your eBay page if you just scroll down a bit.

i connected the 5V to Pul+, Dir+, and EN+ as he did from the arduino power pins, everything worked fine,
i just didnt want to make mistakes and damage so i was extra cautious.

the motor now is rotating but i got a few more questions maybe, i'll post another thread with the specific questions.

No, don't cross post, keep the discussion here.