Stepper Newb

Projects General Guidance
1

First Time using Steppers and before I hook them up I just want to clarify a few things because I'm allergic to magic smoke :o

Hardware:
2x Nema23 Stepper Motors 11.5 lb/inch(1.26 Nm) 2.8A 2.5mH .9ohms (DATASHEET)
2x DM542S Stepper Driver (DATASHEET)
Power Supply 150w 36v 4.17A (DATASHEET)

Software:
AccelStepper

I had ordered a 24v 6.5A power supply but this is what arrived. Since specs call for only 1 stepper motor to be active at any given time I think this will be ok and a little extra speed never hurts right? :smiling_imp:

#1: Signal Wires

The datasheet shows 2 ways to connect to a micro controller. I believe that they should be
hooked up as shown in Fig. 4 (common cathode) Though I'm not sure why exactly.
]

Stepper driver connections.png
Stepper driver connections.png844×294 25.3 KB

#2: Signal from AccelStepper

I believe that the datasheet for the DM542S shows that it expects the signal to go from HIGH to LOW to initiate a step. The only mention I could find in AccelStepper seems to indicate the opposite. Will I need to use AccelStepper.setPinsInverted() to fix this?

/// \param[in] pin1 Arduino digital pin number for motor pin 1. Defaults
/// to pin 2. For a AccelStepper::DRIVER (interface==1),
/// this is the Step input to the driver. Low to high transition means to step)

Stepper Signal.png

#3: The Enable Pin

It seems that the only reason to use the enable is to shut off power to the stepper motor
when not in use. One of these steppers will spend 98% of it's time doing nothing with no load applied.
Are the power savings worthwhile or not worth bothering? Or maybe it's about motor temperature?

#4: Buck converter

Is it ok to use a buck converter to bring the 36v of the power supply down to 7v to feed into the uno's regulator or would it be better to use a separate phone charger(wall wart) to provide for the uno?

EDIT:
#5: Full Step

I almost forgot. How do you set full step mode? The driver has switches to set the microstepping but nowhere do I see where to set full step.

Thanks for taking the time to look!

Stepper driver connections.png
Stepper driver connections.png844×294 25.3 KB

Stepper Signal.png

2

It is unlikely to matter whether you choose common anode or common cathode.

My advice is to connect it up with a simple program that makes the motor move VERY slowly and see if it works.

...R
Stepper Motor Basics
Simple Stepper Code

3

#1, Arduino outputs are push/pull, either should work.

#2, selectable via jumper, manual page 3, fig 2.

#3, standstill current can be reduced to 50%, page 8.

#4, why not bring it down to 5V and connect to USB socket or 5V pin, bypassing the onboard regulator?

#5, looks like 1/2 step is the minimum (400 steps per rev).