Hello from Reno NV.

@will I get this message during an attempt to compile my sketch?  I can't find a reference to it anywhere.  

@olddude 

Seriously ?

Think how we're supposed to explain a compile time error that you get compiling your sketch when you don't show us either the error message nor the code.

@will @olddude See Help for instructions how to post code and post a picture of the error

@olddude Also, it would help if we knew what your invention is, pictures, some sort of description?

@will  Here is my first attempt to write a sketch.

void setup() {
const int STEPS_PER_REV = 200;
const int SPEED_CO
Stepper stepper_NEMA17(STEPS_PER_REV), 8,9,10,11);

}
void loop() {

stepper_NEMA17SetSpeed. setSpeed(motorSpeed);
stepper_NEMA17. step(STEPS_PER_REV / 100);
Delay Microseconds (1000);
]
]

This is the response from Arduino

void setup() {
const int STEPS_PER_REV = 200;
const int SPEED_CO
Stepper stepper_NEMA17(STEPS_PER_REV), 8,9,10,11); This line is highlighted (error msg below)

}
void loop() {

stepper_NEMA17SetSpeed. setSpeed(motorSpeed);
stepper_NEMA17. step(STEPS_PER_REV / 100);
delayMicroseconds(1000);
]
]

(expected initializer before 'stepper'

@olddude Please read HELP on how to post code and post a picture of the error you get with a screen grab (Mac Shift Cmd 4, Win ?????)

@zander 

will do

This should work better, but the SPEED_CO statement needs finishing.  And see other comments in code.

// These are called global variables and constants.  
// They need to be seen by all parts of your code.

const int STEPS_PER_REV = 200;
const int SPEED_CO                               //  <= This is not a statement.
Stepper stepper_NEMA17(STEPS_PER_REV), 8,9,10,11);

void setup() 
{
}

void loop() 
{
  stepper_NEMA17SetSpeed. setSpeed(motorSpeed);
  stepper_NEMA17. step(STEPS_PER_REV / 100);
  // This is not a valid statement... Delay Microseconds (1000);
    delay(1000);   // This is.
// ]  This is not valid here... stray character.
// ]
// You had no curely brace to end
}
 

@olddude Should look like this

void setup() {
const int STEPS_PER_REV = 200;
const int SPEED_CO
Stepper stepper_NEMA17(STEPS_PER_REV), 8,9,10,11);

}
void loop() {

stepper_NEMA17SetSpeed. setSpeed(motorSpeed);
stepper_NEMA17. step(STEPS_PER_REV / 100);
Delay Microseconds (1000);
]
]

@olddude 

This version compiles clean, it doesn't do anything and I guessed at your speed declaration

#include <Stepper.h>

 const int STEPS_PER_REV = 200;
 const int SPEED_CO = 1;
 
Stepper stepper_NEMA17(STEPS_PER_REV, 8, 9, 10, 11);

void setup() {
    stepper_NEMA17.setSpeed(SPEED_CO);
}

void loop() {
    stepper_NEMA17.step(STEPS_PER_REV / 100);
    delayMicroseconds(1000);
}

@will I can't thank you enough.