I have an A4988 driver that I can’t quite figure out. I have it hooked up as per the product description and using this sketch. I am using a 200 step motor as well. My problem is that the only way I can get the motor to turn one full revolution is to change the line: const int stepsPerRevolution = 200; to 800 If I have all the MSx pins open, shouldn’t I be in full step mode? It is acting as though in quarter step mode now, right? I am using a 12v supply set to .7 amps for the stepper. Am I missing something?
Thanks in advance
#include <Stepper.h>
const int stepsPerRevolution = 200; // change this to fit the number of steps per revolution
// for your motor
Stepper myStepper(stepsPerRevolution, 2,3);
void setup() {
// set the speed at 60 rpm:
myStepper.setSpeed(60);
// initialize the serial port:
Serial.begin(9600);
}
void loop() {
// step one revolution in one direction:
Serial.println("clockwise");
myStepper.step(stepsPerRevolution);
delay(500);
// step one revolution in the other direction:
Serial.println("counterclockwise");
myStepper.step(-stepsPerRevolution);
delay(500);
}
The Arduino library you are using is intended for use with H-bridges or darlington arrays, not with the simpler A4988 interface, so it is not producing the proper step/direction inputs for your driver. If you want to test out the driver, your Arduino code can be quite simple: set the direction pin high or low and toggle the step pin; every low-to-high transition on the step pin will step the motor once.
You might find this thread (and its sample code) helpful:
