How to move a servo with a function with parameters

Using Arduino Programming Questions
#1

Im currently trying to control 3 servos with the same movements and pretty much the same code, I use a push button and try to use it as a toggle switch:

int lightON = 180;
int lightOFF = 90;  

buttonState1 = digitalRead(button1);
  if (directionState1 == 0) {
    if (buttonState1 == HIGH ) {
      directionState1 = 1;
      digitalWrite(LED, HIGH);
      servo1.attach(D7);

      Serial.println("Servo 1 is moving");

      for (pos1 = lightOFF; pos1 <= lightON; pos1 += 1) {
        servo1.write(pos1);
        delay(15);
      }

      servo1.detach();
      digitalWrite(LED, LOW);
    }

  } else if (directionState1 == 1) {
    if (buttonState1 == HIGH) {
      directionState1 = 0;
      digitalWrite(LED, HIGH);
      servo1.attach(D7);

      Serial.println("Servo 1 is moving");

      for (pos1 = lightON; pos1 >= lightOFF; pos1 -= 1) {
        servo1.write(pos1);
        delay(15);
      }

      servo1.detach();
      digitalWrite(LED, LOW);
    }
  }

The thing is, this works but my problem is that I have this repeated over 3 times in my code for 3 other servos and the only things changed are the name of the servo and its position. I decided to try and create a function which will let just write it once and run it every time I press the button. This is what I made.

void runServoLight(int pos, int light1, int light2, Servo servo, int state) {

  if (state == 1) {

    digitalWrite(LED, HIGH);
    for (pos = light1; pos <= light2; pos += 1) {
      servo.write(pos);
      delay(15);
    }
    digitalWrite(LED, LOW);

  } else if (state == 0) {

    digitalWrite(LED, HIGH);
    for (pos = light2; pos >= light1; pos -= 1) {
      servo.write(pos);
      delay(15);
    }
    digitalWrite(LED, LOW);

  }
}

The parameters of the function are to control my servos. It doesn’t seem to work and I cant understand why.
This is how it looks now:

buttonState1 = digitalRead(button1);
  if (directionState1 == 0) {
    if (buttonState1 == HIGH) {
      directionState1 = 1;
      servo1.attach(D7);

      Serial.println("Servo 1 is moving");
      runServoLight(pos1, lightON, lightOFF, servo1, 1);

      servo1.detach();
    }

  } else if (directionState1 == 1) {
    if (buttonState1 == HIGH) {
      directionState1 = 0;
      
      servo1.attach(D7);

      Serial.println("Servo Luz 1 en movimiento");
      runServoLight(pos1, lightON, lightOFF, servo1, 0);

      servo1.detach();
    }
  }

I don’t understand what is wrong. I would really appreciate some help. English is not my native tongue so apologies if the grammar is not that good.

#2

Hi,
Can you please post your complete code?
What controller are you using?
Do you have a separate power supply for the servos?

Thanks.. Tom... :slight_smile:

#3

you should use pointer for your servo parameter

void runServoLight(int pos, int light1, int light2, Servo &servo, int state)

runServoLight(pos1, lightON, lightOFF, *servo1, 0);

thx

#4

marcelomm:
It doesn’t seem to work and I cant understand why.

What would it be doing if it did “seem to work”. What is it doing instead?

You can greatly simplify the code by using arrays of constants and variables:

#include <Servo.h>

const int lightON = 180;
const int lightOFF = 90;

const byte ButtonCount = 3;
const byte ButtonPins[ButtonCount] = {2, 3, 4};
const byte ServoPins[ButtonCount] = {7, 8, 9};

boolean ButtonStates[ButtonCount];
boolean LightStates[ButtonCount];

Servo LightswitchServo;

void MoveServo(int index)
{
  LightswitchServo.attach(ServoPins[index]);

  if (LightStates[index])
  {
    // ON
    for (int pos = lightOFF; pos < lightON; pos++)
    {
      LightswitchServo.write(pos);
      delay(15);
    }
  }
  else
  {
    // OFF
    for (int pos = lightON; pos > lightOFF; pos--)
    {
      LightswitchServo.write(pos);
      delay(15);
    }
  }
  LightswitchServo.detach();
}

void setup()
{
  for (int i = 0; i < ButtonCount; i++)
    pinMode(ButtonPins[i], INPUT);
}

void loop()
{
  for (int i = 0; i < ButtonCount; i++)
  {
    boolean buttonState = digitalRead(ButtonPins[i]);
    if (buttonState != ButtonStates[i]) // State Change Detection
    {
      ButtonStates[i] = buttonState;
      if (buttonState)
      {
        // Button was just pressed
        LightStates[i] = !LightStates[i]; // Toggle on button press
        MoveServo(i);
      }
    }
  } // End for i
}
#5