Nema 14 with planetary gear 5:1 and power supply not getting along?

Hello

I am working with a high torque stepper motor(this one together with the A4988. I have connected the Arduino, the power supply and the motor to the driver according to https://www.google.dk/search?q=A4988+arduino&client=firefox-b-ab&dcr=0&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjI6uyYqdLYAhXNZVAKHbUSCusQ_AUICigB&biw=1830&bih=753#imgrc=yQy5vDBDGCVZ1M: . I am using the folowing simple code :

// defines pins numbers
const int stepPin = 4; 
const int dirPin = 5; 
 
void setup() {
  // Sets the two pins as Outputs
  pinMode(stepPin,OUTPUT); 
  pinMode(dirPin,OUTPUT);
void loop() {
  digitalWrite(dirPin,HIGH); // Enables the motor to move in a particular direction
  // Makes 200 pulses for making one full cycle rotation
  for(int x = 0; x < 400; x++) {
    digitalWrite(stepPin,HIGH); 
    delayMicroseconds(500); 
    digitalWrite(stepPin,LOW); 
    delayMicroseconds(500); 
  }
  delay(1000); // One second delay

}

But I find so many issues!

-The power supply gets shortcuted every second
-The motor, at microcontoller restart, shortly turns many times in both directions, before starting with the full cycle turns every second.
-Sometimes it juts gets locked, and won’t turn every second
-The turning direction changes every time I restart the microcontroller

What am I not grasping here?

Did you adjust the motor coil current (pot on the A4988 driver)? Here is a guide on adjusting the coil current on A4988 drivers.

What is the voltage and current rating of the power supply?

I don't see anything in the code that would cause your problems, so I must assume hardware.

How about a picture of your setup that, clearly, shows components and wiring?

Your code seems to be trying to make the motor move 1000 steps per second. Start with a very much slower movement - say 5 steps per second.

...R Stepper Motor Basics Simple Stepper Code

trying to make the motor move 1000 steps per second

Sorry, I don't know why I missed that. It is the same thing the test tube guy was doing.

Start off with a simple test using the AccelStepper library with modest acceleration and speed settings first, you certainly cannot expect a motor to go from stationary to 1000 steps/sec immediately, it will simply stall/miss-step as motors obey the laws of physics, not impossible demands.

You should add a physical pull-down resistor (1k to 10k range) to pin 4 so that the stepper behaves during power-up and reset.

Thanks for your answers guys. Well, even though I still cannot see how from my code I should tell the motor to move 1000 times per second, I started to troubleshoot by uploading Robin2's basic stepper code from his stepper basics thread (really helpful).

Well it did not work either! I started thinking that my bench power supply would be the problem, so I used a laptop converter at 19V.

It did not work.

But by accident when trying to read the voltage at the current limitor on the A4988, it worked! Simply by shortcutting GND and the current limitor I got the codes working. I do not know what this is due to. But I've ordered a new driver and I'll try again :-)

Thanks again,

/Ivan

I still cannot see how from my code I should tell the motor to move 1000 times per second

for(int x = 0; x < 400; x++) {
    digitalWrite(stepPin,HIGH);  
    delayMicroseconds(500);      
    digitalWrite(stepPin,LOW);
    delayMicroseconds(500);

Each of those delayMicrosecond functions wait for 1/2 millisecond. Total time for a cycle = 1 millisecond, result is 1000 pulses (steps) per second.

ivino: Thanks for your answers guys. Well, even though I still cannot see how from my code I should tell the motor to move 1000 times per second, I started to troubleshoot by uploading Robin2's basic stepper code from his stepper basics thread (really helpful).

Thank you for your kind words.

In my examples I have a variable to hold the value of the interval between steps. That is what determines the motor speed.

I don't know what you mean by " shortcutting GND and the current limitor"

...R

Each of those delayMicrosecond functions wait for 1/2 millisecond. Total time for a cycle = 1 millisecond, result is 1000 pulses (steps) per second.

I see now Groundfungus :-) Thanks.

And Robin2, by

" shortcutting GND and the current limitor"

I mean stablishing galvanic connection between the screw on the A4988 board where the current is adjusted and the A4988 GND pin. That really something I have not seen on any tutorial.

/Regards

ivino: And Robin2, by I mean stablishing galvanic connection between"

Is that what I would describe as "soldering a wire between"?

If so, it is certainly not something I ever contemplated. Have you studied the schematic for the A4988 board to figure out the effect of such a connection?

If not, then I still don't understand.

...R