Multiple loops, how can i make it work?

Using Arduino Project Guidance
1

hi, i'm a student just getting to know an arduino uno.

i'm trying to build a very basic code, but can't make it work.

i got two loops

  1. reads the A5 and translate it to voltaje, and increase a variable
  2. print to serial every 1 sec the count variable

this is what i got:

int contar = 0;

void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
}

void loop()
{
int sensorValue = analogRead(A5);
float voltage = sensorValue * (5.0 / 1023.0);
contar = contar + 1;
}
void imprimir ()
{
Serial.println(contar);
delay (1000);
}

thanks for the help.
regard
Yosi

2

You can't use delay() when you want two things to be happening 'at the same time'. Use millis() to schedule periodic events like "print once every second".

void loop()
{
  static unsigned long previousMillis = 0;
  int sensorValue = analogRead(A5);
  float voltage = sensorValue * (5.0 / 1023.0);
  contar = contar + 1;
  if (millis() - previousMillis >= 1000)
  {
    Serial.println(contar);
    previousMillis = millis();
  }
}
3

Welcome to the forum

Please follow the advice given in the link below when posting code, in particular the section entitled 'Posting code and common code problems'

Use code tags (the </> icon above the compose window) to make it easier to read and copy for examination

When you posted your code without code tags did you receive a warning message ?

As to your problem, see Using millis() for timing. A beginners guide, Several things at the same time and the BlinkWithoutDelay example in the IDE

1 Like
4

Hi John, it should be one after another. meaning:

  1. count how many A5 read where made and save it as "contar"
    after that
  2. print to serial contar, and contar should set to 0 again

and loop 1 should run again and loop2 after that.

thanks and regards
Yosi

5

Hi John, your code output got negative values, i'm trying to count how many read of A5 are made every 1000ms :
-22944
-14023
-5093
3829
12760
21681
30611
-25995
-17074
-8143
778
9709
18631
27561
-29045
-20124
-11193

6

So every second you want to know how many times the input was read in the previous second? Just change it to:

  if (millis() - previousMillis >= 1000)
  {
    Serial.println(contar);
    previousMillis = millis();
    contar = 0;  // add this line
  }
7

An 'int' on an Arduino UNO can only count up to 32767. For higher values, change 'int' to 'unsigned long'.

8

Thank you john, now it working

this are the output that i got
8931
8922
8930
8922
8931
8930
8922
8931
8921
8931
8921
8931
8931
8921
8931
8922
8930

that should be how many A5 reads were made?

9

Yes, is there any doubt in your mind?

10

How many times loop() ran, which includes reading A5, incrementing 'contar', calling millis(), subtraction, comparison... If you add anything to loop(), like using the value of 'voltage' for anything' the rate will go down.

11

nope thanks a lot for asking

12

Yes, what is the significance of the number of reads? Don't you want to control the timing of them?

13

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