Stepper Mottors

Hi,

I just bought this stepper motor below to be controled by a arduino UNO:

Elegoo 5 sets 28BYJ-48 ULN2003 5V Stepper Motor + ULN2003 Driver Board for Arduino.

Questions: tutorials all show the pins connected to 8,9,10,11: does that matter? can I use other pins like 5,6,7,8?

What is the stepsPerRevolution?

Step angle: 5.625 x 1/64

It seems to me that it is either: 360/5.625 = 64 (motor itself)

or: 64 x 64 = 4096 (motor + gearing)

However, when i run the motor step by step on one revolution, I count only 2048 steps.

What’s wrong?

Yes, you can use different pins.

What’s wrong?

Are we supposed to guess? Post your code, using code tags.

Thanks. I indeed tried other pins and it works the same.

I confirm that the number of steps per revolution seems to be 20148, which does not seem coherent with the specs… I have asked Elegoo directly, we’ll see what they say.

20148 or 2048?

A little math would help too. 2048 / 64 = 32.

2048 would make the gear ratio 32:1

The site below states they are 64:1

[Link to specs on listed motor

RS](28BYJ-48 Stepper Motor with ULN2003 driver and Arduino Uno – 42 Bots)

See this blog on the various different gear ratio that are associated with that model stepper:

https://grahamwideman.wikispaces.com/Mo … otor+notes

jremington:
See this blog on the various different gear ratio that are associated with that model stepper:

https://grahamwideman.wikispaces.com/Mo … otor+notes

Oh isn’t that handy. :doh:

RS

Thanks all for the responses.

So it turns out to be a 32 steps motor (the step motor itself), but with the gearing at 64:1 , the output shaft has 2048 ‘slow’ steps.

The initial confusion comes from the manufacturer’s specs; 5.625 degree per step: that’s wrong: 360/32 = 11.25 degree.

so the internal stepper has 32 steps and 11.25 degree per step, which translates to 32x64 = 2048 steps and 360/2048 = 0.17578 degree at the output shaft.

The overall package makes for a quite “high def” little stepper assembly!