Hello,
First post…
I’m planning a project using stepper motors. I haven’t really looked at any datasheets or anything, so this may be a fairly stupid and obvious questions.
Why do I need a separate micro control to run a stepper motor (SM)? Based on information that I read various places, I need a U2004 Darlington Array (if using a unipolar stepper) or SN754410ne H-Bridge (if using a bipolar stepper). Why can’t a control the SM directly with the Arduino?
Thank you in advance.
An Arduino cannot produce enough power for any type of motor. The purpose of the motor driver is to convert the control signals produced by the Arduino into suitably controlled power for the motor.
I strongly recommend that you use a specialized stepper motor driver with a bipolar motor rather than a pair of h-bridges which are intended for DC motors.
These links may be useful
Stepper Motor Basics
Simple Stepper Code
...R
Ofcourse, that makes sense. My initial thought was that a stepper was just connected directed to a power source, and a microcontroller regulated the stepping speed.
Thank you for the links. The stepper motor basics explains it very well explained.
When going with a motor driver and steppers, make sure, that you limit the current running through the coils.
Otherwise you can burn your stepper.
If you are looking for the right driver, first have a look at the datasheet of your stepper and look for the maximum allowed current for each coil. This will determine your driver (it should deliver at least around 10-20% more current and the current should then be adjusted to the limit of your stepper motor).
Spattox:
Hello,
First post…I’m planning a project using stepper motors. I haven’t really looked at any datasheets or anything, so this may be a fairly stupid and obvious questions.
Why do I need a separate micro control to run a stepper motor (SM)? Based on information that I read various places, I need a U2004 Darlington Array (if using a unipolar stepper) or SN754410ne H-Bridge (if using a bipolar stepper). Why can’t a control the SM directly with the Arduino?
Thank you in advance.
Your information is rather out of date. Most steppers today (certainly the cheap ones) are low impedance
bipolar and you don't drive them with H-bridges, you use a current-controlling chopper-driver such as
A4988 or DRV8825 modules. These are not microcontrollers, they are motor drivers.
But of course it all depends on which motor you have, that's important to know.
The Arduino cannot drive any motor load, it outputs low current low power signals only, good for
an LED or two, motors take 10 to 100 times more current.