While or if analogRead(A0) not in a range

[brmxcy]

Hello, in college and having some difficulty with one problem. I have a SparkFun kit and im trying to do different tasks based on what value my potentiometer reads. How do I code, "If im not in the range of 257-512, then a light shouldnt go on."? Right now I am having the issue of the light turning on, but not turning off once I turn the knob outside of that range. Heres the snippet of my code I am having problems with.

  while( 257 <= analogRead(A0) <= 512)
  {
    digitalWrite(11, HIGH);
  }
  if()// in the brackets, if analogRead(A0) is not in the range, then then digitalWrite(11,LOW)

[TomGeorge]

Hi, @brmxcy
Welcome to the forum.
Can you please post your complete code?

Do you have a statement that turns the light OFF.

@brmxcy

if()

Will not turn it off.

TIP; Use if... else...

Thanks.. Tom..

[Coding_Badly]

@brmxcy

while( 257 <= analogRead(A0) <= 512)

While that, sadly, is syntactically valid, it does not do what you think it does.

[brmxcy]

Did some modifying. Once the dial reaches the second range, the light becomes red, but doesn't turn off if the dial is moved to another range. If i press the button attached to pin 7 to turn off the light, the light will remain off even if i move dial to another range. Also if you know any way I can use a for loop to replace the first if loop that's be greatly appreciated.

int hertz = 1000;
int bomb = 200;

void setup()
{
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(7, INPUT_PULLUP);
}

void loop()
{
  if(analogRead(A0) >=0 && analogRead(A0) <= 256)
  {
    digitalWrite(9, HIGH);
    delay(200);
    tone(8,hertz,bomb);
    digitalWrite(9, LOW);
    delay(200);
    hertz = hertz +250;
  }
  if(analogRead(A0) >=257 && analogRead(A0) <= 512)
  {
    digitalWrite(11,HIGH);
    if(digitalRead(7)==LOW)
    {
      while(true)
      {
      digitalWrite(11,LOW);
      }
    }
  }
}

[horace]

@brmxcy

  while(true)
      {
      digitalWrite(11,LOW);
      }

once you are in the while(true) loop you will stay there forever
did you intend something like

while(digitalRead(7)==LOW)
      {
      digitalWrite(11,LOW);
      }

the loop exits when you release the button
or possibly

 if(analogRead(A0) >=257 && analogRead(A0) <= 512 && digitalRead(7)==HIGH)
     digitalWrite(11,HIGH);
else
    digitalWrite(11,LOW);

think you need to write out a specification of what the code is required to do

[mancera1979]

@brmxcy

if(analogRead(A0) >=0 && analogRead(A0) <= 256)

analogRead returns an integer number between 0 and 1023. https://www.arduino.cc/reference/en/language/functions/analog-io/analogread/

This means analogRead(A0) >= 0 is always true

The above of condition can then be simplified as
if(analogRead(A0) <= 256)

[TomGeorge]

HI,
Try this, I have taken tone out to JUST work on the flashing.

int hertz = 1000;
int bomb = 200;

void setup()
{
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(7, INPUT_PULLUP);
}

void loop()
{
  if (analogRead(A0) <= 256)
  {
    digitalWrite(9, HIGH);
    delay(200);
    digitalWrite(9, LOW);
    delay(200);
  }
  else
  {
    digitalWrite(9, LOW);
  }
}

Note you will have to wait up to 400ms for any change in the pot value to take effect.

delay is a blocking function.

Better to use "Blink without delay" example in Examples tab of IDE.

Tom..