Hi, im trying to get my new stepper motor to spin with the stepper library example..
/*
* MotorKnob
*
* A stepper motor follows the turns of a potentiometer
* (or other sensor) on analog input 0.
*
* http://www.arduino.cc/en/Reference/Stepper
* This example code is in the public domain.
*/
#include <Stepper.h>
// change this to the number of steps on your motor
#define STEPS 512
// create an instance of the stepper class, specifying
// the number of steps of the motor and the pins it's
// attached to
Stepper stepper(STEPS, 8, 9, 10, 11);
// the previous reading from the analog input
int previous = 0;
void setup()
{
// set the speed of the motor to 30 RPMs
stepper.setSpeed(30);
}
void loop()
{
// get the sensor value
int val = analogRead(0);
// move a number of steps equal to the change in the
// sensor reading
stepper.step(val - previous);
// remember the previous value of the sensor
previous = val;
}
I've made sure my input pins to the driver are connected in the correct order, checked and double checked.
Just a total newbie to this so can't make heads or tails.
I tried the code given on the ebay page(scroll down), that works but only seems to work at delay speeds of 3 and 4, I want to know how I can increase the speed.
I do understand that the library uses a different method than just incrementally firing the coils in order, but it doesn't work.
Any help?
Firstly that motor claims to have 64 steps/rev and a 64:1 reduction gear - making 4096 steps per shaft revolution - so your #define STEPS 512 seems wrong by factor of 8. If you want the shaft to go at 30RPM then that's too much, you're asking
for the motor itself to go at 1920RPM, an order of magnitude too fast for such a motor I think.
I'm not very impressed by their arithmetic as shown in the comments in their code. There may also be some confusion as
to what they mean by steps.
So, I dont think i'm getting the optimum torque for this motor, the 900pps how would I get that?
Is that just 900 Hertz or would I do 900/4 since theres 4 pulses in each rotation?
I did attach a pot to one of the examples for variable speed and managed to get it to spin, however very slow and with low torque.
It would help if you said what you actually want. A stepping motor has maximum torque when it is stopped, the so called holding torque. The faster it moves the lower the torque until a point where it is not able to even over come its own mass, this is called the stall torque.
Basically the higher the current in the motor the higher the torque. To maximise it you need a high voltage and a chopping or current limiting regulator.
Stepping motors are not good for high rotation speeds.