HELP in Multi Stepper Proj. Big Easy Driver(ROB-11876) fries

Hello!

I am trying to control two motors,

For each of them I have a Big Easy Driver from here: https://www.sparkfun.com/products/11876 that are connected to one Arduino Mega (one on the PINS 6 and 7, the other one on 8 and 9)

Both drivers are powered from the same supply, 12V 8A.

these pictures show my elements and the way they are connected:

http://f.cl.ly/items/47230I2V3k2z371M0O3L/photo-3.JPG

http://f.cl.ly/items/2u1j0e251M422R3m1V … %201-1.JPG

http://f.cl.ly/items/0l0j0Y1V0H1V3g0Q3O … %202-1.JPG

I am running both from the same code, first, the Mercury Motor makes a 90° turn, then the pump spins for about 2 or so revolutions.

That’s the theory, but after all was hooked up and prepared, the Driver that is connected to the pump stopped working, the light on it switched off and the pump doesn’t move anymore (I tried different motors attached to it - none of them do).

Any ideas what I did wrong? I am happy about any help, any advise regarding the whole setup. My suspicion is that the current adjust of the (now fried) driver was too high and with the other driver already pulling current, it got too hot and stopped working… But is that possible? is 8A not enough for the two drivers? and isn’t there supposed to be a heat cut off in the big easy drivers? can it be the motor maybe? because it is old?

I am very thankful for any advise you may have,

have a good day,

Leon

ps, thats the code I used:

#include <AccelStepper.h>

// Define a stepper and the pins it will use
AccelStepper stepper(1, 9, 8);

int pos = 0;

void setup()
{  
  stepper.setMaxSpeed(1500);
  stepper.setAcceleration(7000);
  
  pinMode(6, OUTPUT);     
  pinMode(7, OUTPUT);
  digitalWrite(6, LOW);
  digitalWrite(7, LOW);
}

void loop()
{
  if (stepper.distanceToGo() == 0)
  {
    delay(2000);
    pos = 800;
    stepper.move(pos);
  }
  
  while(stepper.distanceToGo() != 0){
  stepper.run();
  }
  
  for(int i = 0; i <=5000; i++){
  digitalWrite(7, HIGH);
  delayMicroseconds(100);          
  digitalWrite(7, LOW); 
  delayMicroseconds(100);
  }
  
  
  
}

If the LED went out it might be a power connection issue. Not sure what those breadboard contacts are rated for, but if you’re drawing 4A (2A/phase) you may have charred some contacts somewhere in the power connections leading to that board. Put a voltmeter on the power in pin on the board and see if 12V is getting to the board. If not, you could try pullling all the power connections in/out to try to rub off possible charring(short term test as it will likely happen again) or wiring directly from your power supply to the board.

[edit]

Some more thoughts…

Your pump motor is four phase, 2A/phase. I’m not sure what the implications are for trying to drive it with only two phases. Also, the SFE product page for the Big Easy Driver only recommends driving 1.4A/phase and recommends heats sinks when getting up there. I didn’t see any heat sinks in your photos.