Loop only runs once

Projects General Guidance
1 
#define led 8
#define Trigger 13
#define Echo 12

void setup(){
  Serial.begin(9600);
  pinMode(led, OUTPUT);
  pinMode(Trigger, OUTPUT);
  pinMode(Echo, INPUT);
  digitalWrite(Trigger, LOW);
}

void loop(){
  long t;
  long d;
 
 digitalWrite(Trigger, HIGH);
 delayMicroseconds(10);
 digitalWrite(Trigger, LOW);

 t = pulseIn(Echo, HIGH);
 d = t/59;

 if (d<10){
  digitalWrite(led,HIGH);
 }else{
  digitalWrite(led,LOW);
 }

}
2

Since you have serial.print() available to show you a message, why not use it to verify your assumption?

3

Thanks! Its looping but i am not getting any readings from the ultrasonic sensor

4

Solved it, i had defined them wrong and i had put the cables in the wrong polarity, the tutorial i saw put them wrong.

5

You are also jumping to conclusions that are not necessarily true! Why not add a time-out value to the pulseln function call? Might also add a test to see if you got a valid return time or got the time-out time. Only then can you know if you got an echo.

6

The function times out by default after 1000 milliseconds, so any other activity would happen only once a second in the absence of quickly returned pulses.

   pulseIn(pin, value, timeout);

pukseIn() accepts a third parameter, the timeout interval in milliseconds. If you try it, set it to something like 2 or 3 times the longest you expect to wait for a valid pulse.

Also handy to test is the returned value, where 0 will mean you did not get a pulse within the timeout period.

See

https://docs.arduino.cc/language-reference/en/functions/advanced-io/pulseIn/

where I just again "learned" about that. The beauty of being older - you can learn something every day and who cares if it's something you've forgotten as many times as you had. :expressionless:

a7

7

Thanks for reminding me too.

8

Hi, @bautic
Welcome to the forum.

You might like to try the NewPing library to do the Ultrasonic work for you.

https://docs.arduino.cc/libraries/newping/

If you are using the IDE 2x then you shold just have to install it.

Tom.... :smiley: :+1: :coffee: :australia: