Hi can some one help me with this?

Projects Programming
1 
int readUltrasonicDistance (int triggerPin, int echoPin)

why does the "int triggerPin, int echoPin" is in the () and not in diffrent line like this:

int readUltrasonicDistance 
int triggerPin
int echoPin

if someone can help me here thx alot!

2

It declares variables in a way that assigns them for a different purpose in each case. To know why, you need to study some C.

3

Needs more context, but it looks like it might be a function declaration, saying that the readUltrasonicDistance function has the two inputs with those other names for the next block of code.

4

I agree, you are not following the forum guidelines for asking a question. In particular, snippets of code are rarely useful because they truncate valuable context.

1 Like
5 
int ultra = 0;

int readUltrasonicDistance (int triggerPin, int echoPin)
{
  pinMode(triggerPin, OUTPUT);  
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  pinMode(echoPin, INPUT);
  return pulseIn(echoPin, HIGH);
}

void setup()
{
  Serial.begin(9600);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
}

void loop()
{
  ultra = 0.006783 * readUltrasonicDistance(13, 13);
  Serial.print(ultra);
  if (ultra >= 80) {
    digitalWrite(3, HIGH);
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    Serial.println(" : Safe");
  }
  if (ultra > 35 && ultra < 80) {
    digitalWrite(3, LOW);
    digitalWrite(4, HIGH);
    digitalWrite(5, LOW);
    Serial.println(" : Beware");
  }
  if (ultra <= 35) {
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
    digitalWrite(5, HIGH);
    Serial.println(" : Dangerous");
  }
  delay(10); 
}

here is the code
@anon57585045 @DaveX

1 Like
6

Thank you. Google "C++ local variables".

1 Like
7

Thanks. @anon57585045 and I guessed correctly.

Look up how C++ functions work.

8

alr tysm for helping ! @anon57585045 @DaveX

9

The reason why we don't want to answer here, it's because it's like writing the same textbook that has been written and refined 1000x. You will get a better answer there, and a good answer wouldn't fit here due to space limitations.

No idea what a "alr tysm" is...

1 Like
10

alr = alright , tysm = thank you so much

11

Did you mean "alr == alright , tysm == thank you so much"?

1 Like
12

And one output?

13

You'll find your list of helpers gets shorter and shorter, the more you continue with this gibberish.
Members have the ability to set you to "ignore", and will never see your posts.
It's a free world, up to you.

14

But, alr and tysm are looked like new internet slangs. Should we learn/ignore it?

alrtysm
alrtysm808×125 11.6 KB

15

Welcome to Y2K. : ) Pager code is out. 143. SMS is in.

16

This will take (receive) two arguments (inputs)

(triggerPin, echoPin)

into the function readUltrasonicDistance , and as we all learned in maths, a function can receive multiple inputs, but only one real output. The output of readUltrasonicDistance is the int:

return pulseIn(echoPin, HIGH);
17

It could be more if the function returns a structure.

18

Yes. To the detriment of the centuries-defined "y=f(x)"

1 Like
19

A function still returns just one structure, array, object or whatever.

And the OP was asking about the inputs.

20

I would be the "xy problem."

Redeemed!

1 Like