How to execute functions simultaneously in this case?

Projects Programming
19

Building off the example from @gcjr, this illustrates how you can do several things

  1. the LED blinking is totally contained without its own function. Just call it often and it updates as needed
  2. checking for a button press every time through loop so it is responsive and blinking the build-in LED as well as starting/stopping the motor and reversing direction.
  3. updating the motor every time through loop but using global variables since there are several functions involved with the motors

any or all of these techniques can by used
(untested)

#define LIGH_PIN_14 9
#define STEPPER_PIN_1 5
#define STEPPER_PIN_2 6
#define STEPPER_PIN_3 7
#define STEPPER_PIN_4 8


enum { Off = HIGH, On = LOW };

const byte pinsLed [] = { 10, 11, 12 };
const byte N_LED = sizeof(pinsLed) / sizeof(pinsLed[0]);

const byte pinBut = A1;
byte stateBut = HIGH;

bool isMotorRunning = false;
bool motorDir = false;
int motorStepIdx;
const int MAX_MOTOR_COUNT = 3000;

unsigned long currentTime;

/*
   Sequence the LEDs every 100 msec
*/

void seqLed (void) {
  static int  idx = 0;
  static unsigned long lastTime;
  const unsigned long interval = 100;

  if ( currentTime - lastTime >= interval ) {
    // time to do next action
    lastTime = currentTime;

    digitalWrite (pinsLed [idx], Off);
    idx = (idx + 1) % N_LED;
    digitalWrite (pinsLed [idx], On);
  }
}

void startMotor(bool state) {
  isMotorRunning = true;
  motorStepIdx = 0;
  motorDir = state;
  if (motorDir ) {
    digitalWrite( LIGH_PIN_14, HIGH );
  }
  else {
    digitalWrite( LIGH_PIN_14, HIGH );
  }
}

void stopMotor() {
  isMotorRunning = false;
}


void updateMotor() {

  static unsigned long lastTime;
  const unsigned long interval = 5;

  if ( currentTime - lastTime >= interval ) {
    lastTime = currentTime;
    OneStep(motorDir);
    motorStepIdx++;
    if ( motorStepIdx >= MAX_MOTOR_COUNT ) {
      stopMotor();
    }
  }
}

void OneStep(bool dir) {
  static byte step_number;

  if (dir)
  {
    switch (step_number)
    {
      case 0:
        digitalWrite(STEPPER_PIN_1, HIGH);
        digitalWrite(STEPPER_PIN_2, LOW);
        digitalWrite(STEPPER_PIN_3, LOW);
        digitalWrite(STEPPER_PIN_4, LOW);
        break;
      case 1:
        digitalWrite(STEPPER_PIN_1, LOW);
        digitalWrite(STEPPER_PIN_2, HIGH);
        digitalWrite(STEPPER_PIN_3, LOW);
        digitalWrite(STEPPER_PIN_4, LOW);
        break;
      case 2:
        digitalWrite(STEPPER_PIN_1, LOW);
        digitalWrite(STEPPER_PIN_2, LOW);
        digitalWrite(STEPPER_PIN_3, HIGH);
        digitalWrite(STEPPER_PIN_4, LOW);
        break;
      case 3:
        digitalWrite(STEPPER_PIN_1, LOW);
        digitalWrite(STEPPER_PIN_2, LOW);
        digitalWrite(STEPPER_PIN_3, LOW);
        digitalWrite(STEPPER_PIN_4, HIGH);
        break;
    }
  }
  else
  {
    switch (step_number)
    {
      case 0:
        digitalWrite(STEPPER_PIN_1, LOW);
        digitalWrite(STEPPER_PIN_2, LOW);
        digitalWrite(STEPPER_PIN_3, LOW);
        digitalWrite(STEPPER_PIN_4, HIGH);
        break;
      case 1:
        digitalWrite(STEPPER_PIN_1, LOW);
        digitalWrite(STEPPER_PIN_2, LOW);
        digitalWrite(STEPPER_PIN_3, HIGH);
        digitalWrite(STEPPER_PIN_4, LOW);
        break;
      case 2:
        digitalWrite(STEPPER_PIN_1, LOW);
        digitalWrite(STEPPER_PIN_2, HIGH);
        digitalWrite(STEPPER_PIN_3, LOW);
        digitalWrite(STEPPER_PIN_4, LOW);
        break;
      case 3:
        digitalWrite(STEPPER_PIN_1, HIGH);
        digitalWrite(STEPPER_PIN_2, LOW);
        digitalWrite(STEPPER_PIN_3, LOW);
        digitalWrite(STEPPER_PIN_4, LOW);
    }
  }
  step_number = (step_number + 1) % 4;
}

// -----------------------------------------------------------------------------


// -----------------------------------------------------------------------------
void setup () {
  Serial.begin (9600);

  pinMode (LED_BUILTIN, OUTPUT);

  for (unsigned n = 0; n < N_LED; n++)  {
    pinMode (pinsLed [n], OUTPUT);
    digitalWrite (pinsLed [n], Off);
  }

  pinMode (pinBut, INPUT_PULLUP);
}

void loop () {

  currentTime = millis();

  seqLed();

  // toggle builtin-led on button press
  byte but = digitalRead (pinBut);
  if (stateBut != but)  {
    stateBut = but;
    delay (10);     // debounce

    if (LOW == but)  {
      Serial.println ("press");
      digitalWrite (LED_BUILTIN, ! digitalRead (LED_BUILTIN));
      if (isMotorRunning) {
        stopMotor();
      }
      else {
        startMotor(!motorDir);  // begin in the other direction
      }
    }
  }

  updateMotor();
}