Servo Speed Changer with Buttons

Question

ok so yesterday i was in trouble with the buttons, with help from you i got over it and everything worked fine with the 1st speed of the servo, then i added the other 2 speeds and it looks like it all messed up... the buttons don`t respond as they should and the servo moves very weirdly. Here is the code:

const int button1Pin = 2;
const int button2Pin = 3;
const int ledPin1 = 13;
const int ledPin2 = 12;
const int ledPin3 = 11;
#include <Servo.h>
Servo servo1;


int x = 0;
int button1State = 0;
int lastButton1State = 0;
int button2State = 0;
int lastButton2State = 0;



void setup() {
  servo1.attach(9);
  pinMode(button1Pin, INPUT);
  pinMode(button2Pin, INPUT);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
    int position;
    button1State = digitalRead(button1Pin);
    button2State = digitalRead(button2Pin);

      if (button1State != lastButton1State)
     {
        if (button1State == HIGH) 
          {
            x++;
            Serial.println("on1");
            Serial.print("number of button Pushes:  ");
            Serial.println(x);
          }
        else 
          {
            Serial.println("off1");  
          }
     }

    if (button2State != lastButton2State)
      {    
        if (button2State == HIGH) 
          {
            x--;
            Serial.println("on2");
            Serial.print("number of button Pushes:  ");
            Serial.println(x);
          }
        else 
          {
            Serial.println("off2"); 
          }
       }
          delay(1000);

lastButton1State = button1State;
lastButton2State = button2State;

  if(x == 1)
    {
      digitalWrite(ledPin1, HIGH);
      digitalWrite(ledPin2, LOW);
      digitalWrite(ledPin3, LOW);
        for(position = 0; position < 360; position += 2)
          {
            servo1.write(position);
            delay(20);
          }
    }
   else if (x == 2)
    {
      digitalWrite(ledPin1, LOW);
      digitalWrite(ledPin2, HIGH);
      digitalWrite(ledPin3, LOW);
        for(position = 0; position <360; position += 5)
          {
            servo1.write(position);
            delay(20);
          }
    }
   else 
    {
      digitalWrite(ledPin1, LOW);
      digitalWrite(ledPin2, LOW);
      digitalWrite(ledPin3, HIGH);
        for(position = 0; position < 360; position += 10)
          {
            servo1.write(position);
            delay(20);
          }
    }
}

Answer 1

There may be better ways to mitigate button bounce. Check this link for a discussion on button bounce and example code to work around this problem. In your code, it appears you can not press your buttons faster than once a second.

Determine if the servos you are using are capable of the range you are demanding. Some servos only travel from 0 degrees to 180 degrees. Your code is asking the servo to travel from 0 degrees to 360 degrees. Also, it is unlikely that any normal servo can travel this far. Most servos use a potentiometer as a feed back sensor. And most potentiometers can only be turned to something less than 1 full revolution.

It is likely you have not given the servos enough time to move to the zero degree position at the start of each of your 3 loops. Understand that normal servos can not make complete revolutions. They need to stay within their designed limit of rotation. If you want to start over at 0 degrees you need to allow the servos time to rotate back in reverse to the 0 degree position.

Consider your last loop. You are asking the servo to move from 0 degrees to 360 degrees in 10 degree steps. You are allowing 20ms per step. That means the servo will be demanded to move almost a complete revolution in (((360 / 10) * 0.020 = 0.72 seconds) less than a second. Some but not all servos can move that fast.