Stepper motor library:

```
#include "stepperMotor.h"
#include "mbed.h"
int motorSpeed; // Steper speed
sMotor::sMotor(PinName A0, PinName A1, PinName A2, PinName A3) : _A0(A0), _A1(A1), _A2(A2), _A3(A3) { // Defenition of motor pins
_A0=0;
_A1=0;
_A2=0;
_A3=0;
}
void sMotor::anticlockwise() { // rotate the motor 1 step anticlockwise
for (int i = 0; i < 8; i++) {
switch (i) { // activate the ports A0, A2, A3, A3 in a binary sequence for steps
case 0: {
_A0=0;
_A1=0;
_A2=1;
_A3=0;
}
break;
case 1: {
_A0=0;
_A1=0;
_A2=0;
_A3=0;
}
break;
case 2: {
_A0=0;
_A1=0;
_A2=0;
_A3=1;
}
break;
case 3: {
_A0=0;
_A1=1;
_A2=0;
_A3=1;
}
break;
case 4: {
_A0=0;
_A1=1;
_A2=1;
_A3=1;
}
break;
case 5: {
_A0=1;
_A1=1;
_A2=1;
_A3=1;
}
break;
case 6: {
_A0=1;
_A1=0;
_A2=1;
_A3=1;
}
break;
case 7: {
_A0=1;
_A1=0;
_A2=1;
_A3=0;
}
break;
}
wait_us(motorSpeed); // wait time defines the speed
}
}
void sMotor::clockwise() { // rotate the motor 1 step clockwise
for (int i = 7; i >= 0; i--) {
switch (i) {
case 0: {
_A0=0;
_A1=0;
_A2=0;
_A3=1;
}
break;
case 1: {
_A0=0;
_A1=0;
_A2=1;
_A3=1;
}
break;
case 2: {
_A0=0;
_A1=0;
_A2=1;
_A3=0;
}
break;
case 3: {
_A0=0;
_A1=1;
_A2=1;
_A3=0;
}
break;
case 4: {
_A0=0;
_A1=1;
_A2=0;
_A3=0;
}
break;
case 5: {
_A0=1;
_A1=1;
_A2=0;
_A3=0;
}
break;
case 6: {
_A0=1;
_A1=0;
_A2=0;
_A3=0;
}
break;
case 7: {
_A0=1;
_A1=0;
_A2=0;
_A3=1;
}
break;
}
wait_us(motorSpeed); // wait time defines the speed
}
}
void sMotor::step(int num_steps, int direction, int speed) {// steper function: number of steps, direction (0- right, 1- left), speed (default 1200)
int count=0; // initalize step count
motorSpeed=speed; //set motor speed
if (direction==0) // turn clockwise
do {
clockwise();
count++;
} while (count<num_steps); // turn number of steps applied
else if (direction==1)// turn anticlockwise
{
count=0;
do {
anticlockwise();
count++;
} while (count<num_steps);// turn number of steps applied
}
}
```

I tried different methods to change the speed (delay of stepper motor) but it is not working.

I am trying to get the motion as shown in this video Pick and place robot