First line of print not getting dispayed

Projects Programming
1

To learn about arrays I wrote this simple sketch. It creates a 21 element array and should print out 21 pairs of lines. But I don't see why the first line does not get printed properly?

const int folderCount = 21;  // Number of elements (folders)

int subtractions[folderCount] = {0, 157, 21, 154, 153, 152, 151,
                                 49, 166, 149, 21, 206, 134, 133,
                                 33, 127, 41, 31, 15, 114, 252
                                };
void setup()
{
  Serial.begin(9600);
  for (int i = 1 ; i <= folderCount; i++)
  {
    Serial.print("In folder number ");
    Serial.println(i);
    Serial.print("Subtract this: ");
    Serial.println(subtractions[i - 1]);
    delay(100);
  }
}

void loop()
{

}

And when I copy paste the first few lines of output here, why does it only paste a single time stamp ?

17:12:41.691 ->


I tried a screenshot and a link, but both failed. What I wanted to show was that the text for that first line appears far over to the right.
2

Arrays go from 0

3

But have I not accounted for that with

Serial.println(subtractions[i - 1]);
4

An array index begins with 0
And therefore ends with 1 less than the length of the array

5

I know, but my code takes account of that. It runs as it should, except for the format issue I described.

6

Sorry, couldn't see the output.
Try a simple test:

I added a new print statement before the if loop.
If this prints correctly it will let you know that it is not your array causing trouble. I don't see anything obviously wrong with your print statements.

7

Sorted: I was viewing the monitor directly after uploading the sketch. Is that known to be flaky in presenting the first line?

If instead I started with a reset, the first line was correctly displayed,

8

I have encountered some flakiness in the first of the output when using certain boards at one time.

I don't remember the exact details, but I think Arduino actually made a fix for it. I remember I was able to work around it by adding a short delay in setup to give a little time before the first output.

Which Arduino board are you using?

Which version of the Arduino IDE are you using?

9

Hi,
Use 115200baud for the serial monitor.

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

10

Using a UNO with 1.8.19.

11

OK, I don't know of any problems with that combination

12

has your Uno CH340 as USB chip?

13

No, it's a 328.
EDIT: Sorry, reckon I didn't read your question correctly. The MCU is 328, but I guess you mean the tiny square chip near the USB socket. Can't identify that.

BTW, I almost always get two identical lines at the start of any printing, directly following upload.

14

because the sketch starts and then Serial Monitor reconnects and resets the Arduino

15

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