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Topic: calculating average from the input (Read 347 times) previous topic - next topic

brutal_magnet

Hi, I have this program which you will input a number. It will tell whether which digit is the smallest and which is the biggest and this part works fine. What I can't get to work is the average part wherein if I input '1234' it will add 1+2+3+4 and divide the sum by 4. if I run this it gives me an output of '50'. I also need the ave to be in the form of number and not in ascii form. I can't seem to find the problem.Please help.Thanks!

Code: [Select]
char output[5];
int sum=0;

void loop()
{
  if (Serial.available() > 0)
  {
    delay(10);
    int x = 0;
    while (Serial.available()>0)
    {
      output[x] = Serial.read();
      output[x+1] = '\0';
      x++;
    }
   
    if (x>=5 || x<4)
    {
      Serial.println("The input must be 4 bytes.");
    }
    else
    {
      int input = atoi(output);
      Serial.print("The value is: ");
      Serial.println(input);         
      Serial.print("1st byte is: ");
      Serial.println(output[0]);
      Serial.print("2nd byte is: ");
      Serial.println(output[1]);
      Serial.print("3rd byte is: ");
      Serial.println(output[2]);
      Serial.print("4th byte is: ");
      Serial.println(output[3]);

      if (min(output[0],output[1])<min(output[2],output[3]))
      {
        Serial.print("Byte ");
        Serial.print(min(output[0],output[1]));
        Serial.println(" is the smallest byte.");
      }
      else
      {
        Serial.print("Byte ");
        Serial.print(min(output[2],output[3]));
        Serial.println(" is the smallest byte.");
      }
      if (max(output[0],output[1])>max(output[2],output[3]))
      {
        Serial.print("Byte ");
        Serial.print(max(output[0],output[1]));
        Serial.println(" is the biggest byte.");
      }
      else
      {
        Serial.print("Byte ");
        Serial.print(max(output[2],output[3]));
        Serial.println(" is the biggest byte.");
      }
     
      for (x=0;x<5;x++)
      {
        sum+=output[x];
      }
      int ave=sum/4;
      Serial.println(ave);
    }
  }

}

AWOL

See my reply to your other question.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

David Pankhurst

You're dealing with numbers and text in the same code, which can be tricky. 1 is one, unless it's the text (ASCII) '1', in which case it's 49. Your average is for the ASCII values, so 50 is almost correct for avg of 1+2+3+4 (it should be 2.5, but integers through away the fraction). One option is to convert ASCII to number as soon as possible, and work with that.

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