Stepper Motor Query

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

OK, so I'm attempting to build a stepper motor driven Rev Counter... I've tried the search function and it throws up a bunch of stuff I don't get a definitive answer to.

Is

// change this to the number of steps on your motor
#define STEPS 100

defined by the stepper motor?

If so, is there a method of determining the amount of steps a motor has?

I am of course assuming that those 100 steps are per full revolution.

In my use I'm only going to need 3/4's of that rev range, so 270 degrees (see piccie below for the guage I'm using - image from fleabay)

I would assume that the amount of steps is down to 360 degrees, so the limitation is on the RPM of the engine to determine it's sweep right?

My application is real world, not sim, so the output is coming from a 12 volt source based on the frequency of it's repetition to generate RPM. Would this need to be stepped down to 5 volts for use with the Arduino?

Apologies for the newb questions, but I'd rather like to get it right(ish) first time than fry equipment.

Cheers,
Rich

2

A steppermotors steps / rev is usullay printed on the motor either as steps pr rev. or as a stepping angle (ie how many degrees each step is)

3

Sweet... Thank You :slight_smile:

I'll rip the clocks apart and see what the story is.

If this information isn't printed on the steps, onto plan B. Programme arduino to carry out 360 steps and see what happens from there in terms of how many revs it does. Divide 360 by the amount of Revs should give me the steps per rev, correct? :smiley:

(EDIT : is doing that likely to kill the motor?

4

Normally there is 1.8 degrees per step. If you can't find out then measure it. That is put a fixed number of steps in and see where it goes. If you have a free rotating motor you can give it many rotations to make the final angle easer to measure. In your case I would write a routine to give a step on a button push and then just count how many you need to get it full scale.