Nema 17, Arduino Uno and stepper motor drive ~2H42B

Question

I tried running Nema 17 stepper motor using the drive in the pic below (not the basic L298N drive, which BTW I successfully used to rotate the motor) .

Could any of you review my existing connections and guide me to complete the remaining ones?

Existing Arduino Uno, Nema 17 motor and drive setup:

Existing connections to Drive from left to right:

1. Thick yellow wire (0v) from power adapter along with a thin black wire (Ground) from Arduino
2. Thick red wire (12v +) from power adapter
3. Green wire (A+) from stepper motor
4. Black wire (A-) from stepper motor
5. Red wire (B+) from stepper motor
6. Blue wire (B-) from stepper motor

What I am missing is connections to PUL, DIR, VCC and ENA. I could put the 4 wires from Arduino D8 to D11 respectively but is that enough? Is there an Arduino sketch I could refer to after the connections are ready?

Answer 1

Here is the user manual for the BH-MSD-2A Micro stepping driver.

Page 5 shows the two tables giving the connections:

You have already connected P2, and that leaves P1 remaining.

The timing diagram below shows the state of the, PUL, DIR and ENA signals required

.

So, the ENA input can either be held high, by connecting to V_CC or connected to a digital output pin of the Arduino, to provide basic ON/OFF control.

This thread, arduino uno with stepper motor, the OP is using a very similar controller to yours, except that theirs is the 6 A version (BH-MSD-6A). Their code, in the thread has a lot of unnecessary code, and apparently has a number of issues. A stripped down version, of the same code, is as follows:

//arduino code
//
#include <TimerOne.h>
#include <EEPROM.h>

int rpm;
int initial_rpm;
int dutycycle_time=0;
int stepper_Enable=5; //STEPPER MOTOR  ENABLE PIN : PUL- 
int stepper_Pulse=6;  // STEPPER MOTOR PULSE PIN :  PUL-

int address_eeprom=0;


void displayNumber(int);
void lightNumber(int);



void setup() 
{                



  Timer1.attachInterrupt( timerIsr ); // attach the service routine here
  pinMode(stepper_Pulse,OUTPUT); // Analog pin A2 is used for ENABLING the steeper motor
  pinMode(stepper_Enable,OUTPUT); // Analog pin A2 is used for DIRECTION the steeper motor
  digitalWrite(stepper_Pulse,HIGH);
  digitalWrite(stepper_Enable,LOW);

  rpm=EEPROM.read(address_eeprom);
}

void loop() 
{


  while(digitalRead(stepper_Enable)==HIGH){
     int cycle_freq=(1600/60)*rpm;
     int dutycycle_freq=2*cycle_freq;
     int dutycycle_time=1000000/dutycycle_freq;
      Timer1.initialize(dutycycle_time); // set a timer of length 100000 microseconds (or 0.1 sec - or 10Hz => the led will blink 5 times, 5 cycles of on-and-off, per second)
      if(analogRead(A3)==LOW )  // STOPPING THE STEPPER MOTOR
       {
         digitalWrite(stepper_Enable,LOW);

       }

  }

  while(digitalRead(stepper_Enable)==LOW)
  {
    int initial_rpm=rpm;
     EEPROM.write(address_eeprom,rpm);

      if(analogRead(A0)==LOW && rpm<300 ) ///increasing speed of stepper motor
    {
          rpm=rpm+1;
         // delay(100);
     }
    if(analogRead(A1)==LOW && rpm>0) ///decreasing speed of stepper motor
    {
          rpm=rpm-1;
         // delay(100);
    }
    if(analogRead(A2)==LOW ) //STARTING THE STEPPER MOTOR
    {
     digitalWrite(stepper_Enable,HIGH);
    }
  }
  if(initial_rpm!=rpm){
    address_eeprom=address_eeprom+1;
  }

}

void timerIsr()
{
  // Toggle LED
  digitalWrite( stepper_Pulse, !digitalRead( stepper_Pulse ));
}

Note that while this should get you started, as the OP states in the thread there are issues with it, that will need fixing.

---

(I have to go now to fix some Marlin firmware, but I'll come back to this answer later)

Answer 2

Connect:

• V_CC to Arduino 5 V
• ENA either directly to V_CC or to an Arduino pin (for optional enable driver software control - active high).

Pulse (steps) and direction to Arduino GPIO.

Have a look here Arduino forum Simple Stepper Program - I think you will find what you are looking for.