Motor Shield Stepper Issue

[snaggletooth]

Hello again,

I have a 2000mA 5V supply connected to EXT PWR and an Arduino Mega 2560 trying to run a stepper motor that requires 2.5 A to drive. I have piggybacked L293DNEs but the motor is not driving a load, leading me to believe that the current supplied directly to the motor is still not enough. My question is a) am I measuring the current right by putting an ammeter in series between a coil of the motor and a slot of M1, and then repeating for the rest of the coils in M1 and M2? If so I am only seeing ~1 mA/coil which is drastically under what I expected.

[adafruit_support_bill]

trying to run a stepper motor that requires 2.5 A to drive. I have piggybacked L293DNEs

The L293D is rated at 600mA. 2 stacked L293D's will get you to about 1A. They are probably going into thermal shutdown with a 2.5A motor.

[snaggletooth]

okay thanks. it turns out i just did not consider all factors. last question. if I acquire two stepper motors with a 5V 1A dependence, will it be better to use piggybacked L293DNE or a single SN754410?

[adafruit_support_bill]

That's a good question. I've never done a head-to-head controlled test.

The limiting factor to piggy-backing is heat dissipation. Since steppers will be pulling the full 1A at all times - moving or standing still, I'd probably go with an SN754410 and a heat-sink.

[snaggletooth]

thanks for all of your help!