Arduino Mega y pololu drv8825

First, I wish to greet all the members of this forum and that these words are worth as presentation.
And, of course, I want to ask a little question I have:

How do I connect pololu driver with arduino mega 8825 2560r3?, I tested with the connection shown in pololu site
Pololu - DRV8825 Stepper Motor Driver Carrier, High Current (md20a) and is not in any way.

To test, I loaded the program on the arduino:

int sleep = 11;
int reset = 10;
int direccion = 9;
int paso = 8;

void setup()
{
pinMode(sleep,OUTPUT);
pinMode(reset,OUTPUT);
pinMode(direccion,OUTPUT);
pinMode(paso,OUTPUT);

pinMode(12,OUTPUT);

digitalWrite(sleep, HIGH);
digitalWrite(reset, HIGH);
digitalWrite(direccion, HIGH);

}

void loop()
{
digitalWrite(12, HIGH);
digitalWrite(paso, HIGH);
delay(100);
digitalWrite(12, LOW);
digitalWrite(paso, LOW);
delay(100);
}
The pin 12 is to see me in a LED each program cycle ...

Awaiting your instructions ...

A greeting.
P.D.: Sorry for the English, is the translator of google.

Your code looks OK to me. Post a photo of the boards, stepper and the wiring between them, then we can see if that looks OK too.

What voltage power supply are you using for the stepper motor?

First of all thanks for answering so quickly.
It is like putting the images in the message. When stepping motor feed him with a 12v source. and noticed that the engine responds something, to play with their coils 12v directly. The scheme is the one in the link in the section where it says "using the driver". What I have is not the 100uF capacitor in the motor supply terminals.

Initializations terminals "sleep" and "reset" for I have put in place instead of directly to +5 v, inicializaras with arduino so you can "play" with the settings to see if it must be HIGH or LOW

Thanks again and I hope your answers.

To put images in the message, click on "Additional Options..." and then "Choose file".

This is the scheme with which I have decided to write the post.

Can you confirm:

  1. You have a wire between one of the Arduino GND pins and the GND connection (next to ¬FAULT) at the bottom right of the DRV8825 board;

  2. You have the other GND connection (the one next to VMOT) on the DRV8825 connected to the negative or common output from the 12V power supply?

I'm playing with drv8825 and I have the same problems. The DRV8825 doesn't work. I use 12V power supply, the wiring is the same you have put in place.
I connected with Arduino only one gnd, because in the driver the gnd pins are already connected.
May be is the capacitor? I don't think because in the manual is written that it is used only to avoid destructive LC voltage spikes.
The mistery is not ended...

GND all the sack of the same power supply generates +5, -5, 0 (GND), +12 and-12V. The LED connected to pin 12 of arduino I use testing as well as I tried to exit the arduino variety STEP.