Atmega168 and L293D controls stepper motor

Hi everyone,

I'm new to Arduino and I'm working on a project. I need to control a 5-wire stepper motor with my Arduino board. I want to use L293D as my driver.

I use my computer's usb to power the Arduino board. My question is, can I power up the L293D using the Arduino board or do I need to use a separate power supply? How can I use the L293D to drive the motor? I want to know the exact circuit configuration to do this.


Do not cross post. The mods won't like it.

The answer to both of your questions is yes.

Sometimes it's nice to show some initiative.

Well the answer to an either-or can't be "yes"... Power the motors (And L293D's Vs) separately from the Arduino. The Vss pin on the L293D is logic supply and should be the Arduino's 5V. Just be sure to use a common ground and have decoupling for the L293D's Vs

Hi MarkT,

What if I use an external power supply to power the arduino, does it mean that I can now use the 5V of the arduino as a supply to the L293D and the motor?

Try not to use the same supply for motors and logic, its fraught with problems.

Okay, thanks for your advice! :)

The Arduino's 5V supply can barely handle the L293D's logic section. Barely meaning after a few hours of run, the regulator will be on the virge of thermal shutdown and the Arduino will be wiggy at best.

hi ajofscott ,

If that is the case, then what should I put on the Vss of the L293D? Another 5V power supply?

Run motor controls on its own supply only share the ground between the sections.