Controlling PWM using push buttons

Other Hardware General Electronics
1

hi friends, First of all i am new to electronics. i am trying to generate PWM signal to control my VFD.
I have made a tinker cad simulation using Arduino UNO. I got the PWM signal and also can control the signal using the push buttons(Increse and decrease). Then, i tried to add one more button to stop and start the loop.i wrote a code but it is not working properly. I got stuck in this step, i have attached the screen shot of the simulation and the code.

can someone help me?

Note: I have attached both the code 1.before adding stop button 2.After adding stop button

Thanks in adance!!

2 button pwm.png
2 button pwm.png1366×560 119 KB

2 button pwm 2.txt (550 Bytes)

pwm + stop.txt (718 Bytes)

2

Please post your code using code tags (The </> button)

3 
int button1=12;
int button2=11;
int button3=4;
int buttonval1;
int buttonval2;
int buttonval3;

int pwmout=3;
int bright=0;
int dt=100;

void setup()
{
  pinMode(button1,INPUT_PULLUP);
  pinMode(button2,INPUT_PULLUP);
  pinMode(button3,INPUT_PULLUP);
  pinMode(pwmout,OUTPUT);
}

void loop()
{
  buttonval1=digitalRead(button1);
  buttonval2=digitalRead(button2);
  buttonval3=digitalRead(button3);
  
  delay(dt);
  
  if(buttonval1==LOW)
  {
    bright=bright+25;
  }
  if(buttonval2==LOW)
  {
    bright=bright-25;
  }
  if(buttonval3==LOW)
  {
    bright=0;
  }
  if(bright>255)
  {
    bright=255;
  }
  if(bright<0)
  {
    bright=0;
  }
  
  
  
  analogWrite(pwmout,bright);
  }
4

So which button is the Stop button? What does it do now? What EXACTLY is it supposed to do?

Steve

5

hi steve,

The push button which is connected to pin 4 is used to stop the motor. This code is working well with the increment and decrement of the motor speed. i want to stop the motor suddenly with a stop button that's y i used

if(buttonval3==LOW)
  {
    bright=0;
  }

could u please check my code.

Thanks for your response

6

That looks like it should do something, if the button is wired correctly with a pull-up resistor.

Note that it doesn't in any sense "stop and start the loop" it just sets the PWM to 0 so in your case LED should go off. To "start" it again you need to press the + button. Isn't that what happens? Or isn't that what you wanted?

Steve

7

Yes, that's what i want. But when i press 'stop' button it is not turning off. should i want to change any thing in my code?

8

I see you've changed the button pinModes to INPUT_PULLUP. How are the buttons wired, particularly the stop button? Do the other two buttons still work to increase/decrease brightness?

Are you still doing this all in Tinkercad rather than in the real world? If so it could be anything. Tinkercad is far from perfect.

Steve

9

Hi steve, you are right. i am confused with the push button concept. i have changed the input to INPUT_PULL and also changed the digital read to HIGH.(It gives output when it reads '1'). Now, it is working fine. Your replies helped me a lot. Thank you, very much.

int button1=12;
int button2=11;
int button3=4;
int button4=2;
int buttonval1;
int buttonval2;
int buttonval3;
int buttonval4;

int pwmout=3;
int bright=0;
int dt=100;

void setup()
{
  Serial.begin(9600);
  pinMode(button1,INPUT_PULLUP);
  pinMode(button2,INPUT_PULLUP);
  pinMode(button3,INPUT_PULLUP);
  pinMode(button4,INPUT_PULLUP);
  pinMode(pwmout,OUTPUT);
}

void loop()
{
  buttonval1=digitalRead(button1);
  buttonval2=digitalRead(button2);
  buttonval3=digitalRead(button3);
  buttonval4=digitalRead(button4);
  
  delay(dt);
  Serial.println(buttonval1);
  if(buttonval1==1)
  {
    bright=bright+25;
  }
  if(buttonval2==1)
  {
    bright=bright-25;
  }
  if(bright>255)
  {
    bright=255;
  }
  if(bright<0)
  {
    bright=0;
  }
 if(buttonval3==1)
  {
    bright=0;
 }
   if(buttonval4==1)
  {
    bright=25;
 }
  analogWrite(pwmout,bright);
  }
10 
int button1=12;
int button2=11;
int button3=4;
int button4=2;
int buttonval1;
int buttonval2;
int buttonval3;
int buttonval4;

Next up, arrays :wink: