#include <AccelStepper.h>
#include <avr/interrupt.h>
#include <avr/io.h>

#define STEP_PIN 12
#define DIR_PIN 13
#define USART_BAUDRATE 9600

const int stepsPerRevolution = 200;
const uint16_t NUMBER_OF_SPINS = 7500;
const uint16_t STEPPER_MAX_SPEED = 1000;
const uint8_t STEPPER_ACCELERATION = 10;

AccelStepper myStepper(1, STEP_PIN, DIR_PIN);

void setup() {
  Serial.begin(9600);
  Serial.println("CNC WINDING MACHINE");
  Serial.println("SHUT UP AND MAKE PICKUPS!!");

  myStepper.setAcceleration(STEPPER_ACCELERATION);
  myStepper.setMaxSpeed(STEPPER_MAX_SPEED);

  attachInterrupt(2, handleCommands, HIGH);
}

void loop() {
  myStepper.move(stepsPerRevolution *  NUMBER_OF_SPINS);
}

void handleCommands() {
   int i;
   int length = Serial.available();

   String cmd = "";
   //copy data out of the receive buffer
   for(i = 0; i < length; i++) {
      cmd += Serial.read();
   }

   //run a string compare function, or otherwise parse the received data
   if(cmd.equals("stop") ){
      myStepper.stop();
      Serial.println("OK. Take a cup of tea. I'll be missing you!");
   } else if ( cmd.equals("start") ) {
      Serial.println("Prepare to FIGHT!");
      myStepper.run();
   }
}