auto create variables

Projects Programming
1

My project has 28 doors. I’d like to create a simple variable that is basically it’s position, R1C1 would the first door. There are 5 rows, and 7 columns (R5C7 would be the last one) I’ve been typing them in then thought it should be easy to use a couple for loops or while and create them quickly but after 3 days of trying it’s time for a little help.

2

Sounds like you need an 2-dimensional array: array - Arduino Reference

3

tperry724:
My project has 28 doors. I’d like to create a simple variable that is basically it’s position, R1C1 would the first door. There are 5 rows, and 7 columns (R5C7 would be the last one) I’ve been typing them in then thought it should be easy to use a couple for loops or while and create them quickly but after 3 days of trying it’s time for a little help.

As always, post your code so far...

4

MarkT:
As always, post your code so far...

In code tags, please.

5

Opps...forgot the code

Code is a language where punctuation and syntax are everything. And here is no intuition on the part of the computer.

Been working really hard at this. Takes times I'm sure.

void setup() {
// put your setup code here, to run once:

Serial.begin(9600);

int row = 1;
for ( int row = 0; row >= 5; row++) {

Serial.print("R");
Serial.print(row);

int col = 1;
for ( int col = 0; col >= 7; col++)
{
Serial.print("C");
Serial.print(col);
Serial.println();

delay(100);

}
}
}

void loop() {
// put your main code here, to run repeatedly:

}

6

Several items. First, please use code tags when you post code or error messages. It should look like this.

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  int row = 1;
  for ( int row = 0; row >= 5; row++) {
    Serial.print("R");
    Serial.print(row);
    int col = 1;
    for ( int col = 0; col >= 7; col++)
    {
      Serial.print("C");
      Serial.print(col);
      Serial.println();
      delay(100);
    }
  }
}

void loop() {
  // put your main code here, to run repeatedly:

}

Second, notice how the code is formatted? While in the IDE hit CTRL-T to auto format. This makes the code easier to read and makes it MUCH easier to find mismatched curly brackets.
Also I removed the unnecessary white space, extra blank lines.

Now, you posted code but have not mentioned it if produced the results you wanted or not.
A good way to describe any difficulties with the code is in this format;
I expected the code to do this.
Instead it did that.
You might even give details on how this and that differ if you think it will help us understand your issue.

You mentioned 28 doors. Then you mentioned 5 rows and 7 columns. 5 * 7 is 35.
How many doors do you have?

Codewise, I think you have confusion on for loops and scope of variables.

 int row = 1;
  for ( int row = 0; row >= 5; row++)

The second line declares the variable row. Its scope is limited to just the for loop between the curly brackets.
The variable that you declare on the first line of the snippet appears to not be used. You set it to 1 but then it is never used.
The for loop has 3 pieces inside the parentheses - initialization, test condition to repeat loop and increment.
You initialize row to 1.
You tell it to repeat while row is greater or equal to 5.
You increment row by 1.
It could be me, but I am used to seeing the end condition test being something like row < 5

Here is a for loop from a c# reference:

for (int i = 0; i < 5; i++) 
{
  Console.WriteLine(i);
}

All this also applies to your loop on columns.