Stepper Motor Test not working (2 replies)

Hi There,

I have recently purchased the Mega 2560 board with RAMP 1.4.
I have connected the 5V + 12 V ATX power supplies.
I am struggling to get the Stepper motor to move in my tests before I hook it up in the CNC machine I am building.

Please help !!!

I have written a test sketch and uploaded to the board:

#define X_STEP_PIN 54
#define X_DIR_PIN 55
#define X_ENABLE_PIN 38
#define X_MIN_PIN 3
#define X_MAX_PIN 2

#define LED_PIN 13


void setup() {
pinMode(LED_PIN , OUTPUT);

pinMode(X_STEP_PIN , OUTPUT);
pinMode(X_DIR_PIN , OUTPUT);
pinMode(X_ENABLE_PIN , OUTPUT);
//PULL ENABLE PIN ON A4988 TO LOW
digitalWrite(X_ENABLE_PIN , LOW);
//SET DIRECTION TO BE IN ONE WAY
digitalWrite(X_DIR_PIN , HIGH);
}

void loop () {

digitalWrite(X_STEP_PIN , LOW);
digitalWrite(LED_PIN, HIGH);
delay (1000);
digitalWrite(X_STEP_PIN , HIGH);
digitalWrite(LED_PIN, LOW);
delay (1000);
}

I have checked the voltage at the A4988 pins and all of them are correct - including the step high and low.
Questions:
1. On RAMP do I need to short A4988 REST & SLEEP pins - I read in other places that people had to short them to make the motor move?
2. Is there a way to check the voltage at the 1A 1B 2A 2B pins to verify that A4988 is doing its job
3. Can a motor run with USB power only?