I want to drive a NEMA17 HS4401S-24 stepper motor with a A4988 driver however I’m experiencing very odd issues of the driver randomly working and not. My A4988 is connected to my NodeMCU V3 (ESP) and I’m using this code:
const int dirPin = D0;
const int stepPin = D1;
const int stepsPerRevolution = 2000;
void setup()
{
// Declare pins as Outputs
pinMode(stepPin, OUTPUT);
pinMode(dirPin, OUTPUT);
}
void loop()
{
// Set motor direction clockwise
digitalWrite(dirPin, HIGH);
// Spin motor slowly
for(int x = 0; x < stepsPerRevolution; x++)
{
digitalWrite(stepPin, HIGH);
delayMicroseconds(2000);
digitalWrite(stepPin, LOW);
delayMicroseconds(2000);
}
delay(1000); // Wait a second
// Set motor direction counterclockwise
digitalWrite(dirPin, LOW);
// Spin motor quickly
for(int x = 0; x < stepsPerRevolution; x++)
{
digitalWrite(stepPin, HIGH);
delayMicroseconds(1000);
digitalWrite(stepPin, LOW);
delayMicroseconds(1000);
}
delay(1000); // Wait a second
}
Note: i have also tried using AccelStepper and Stepper libraries and have experienced the same results.
The behaviour seems to be completely random. First time I uploaded this code to my Arduino, I than connected the power supply to the A4988 for the motor and it works, motor starts spinning as expected.
Then I disconnect the motor power supply to the A4988, I make a small change in code let’s say for the faster loop I change delayMicroseconds to 1500, upload the code and reconnect motor power supply and it’s no longer working. I revert the code and the code that used to work does not work anymore… Complete random. The motor holds with a lot of torque it’s impossible to move the shaft by hand maybe it also buzzes but does not move.
Ok I replace the code with AccelStepper or Stepper implementation with something simple like:
#include "AccelStepper.h"
#define motorInterfaceType 1
AccelStepper ballFeederStepper = AccelStepper(motorInterfaceType, D0, D1);
void setup() {
ballFeederStepper.setMaxSpeed(1600);
ballFeederStepper.setSpeed(600);
Serial.begin(9600);
}
void loop() {
ballFeederStepper.runSpeed();
}
And completely randomly it works or does not work.
Note: when I say it does not work I just mean that motor does not step/move but holds position with high torque. Than I disconnect it go away come back and at times it just starts working. Complete random…
The heat sink does not get hot, i made sure current limiting was set correctly… I’m not sure why this is happening. Is there some procedure to reset the driver after reprograming the ESP. It’s not the wiring. I did connect RST + SLEEP pins…
I’m kinda confused. I have many available news ones from 3 manufacturers (some 70 units) tried multiple and same issues 
I don’t think it’s a defective batch.