Weird Serial.Print() behaviour (Char-Array)

Projects Programming
1

First of all, hi there, thanks that you are reading this.
If you could help me out a bit or point me at least in the direction the error is located i would really appreciate.
Alright, here the Problem:

I have a const PROGMEM char - (2D)-Array to store '\0' - terminated strings in.

const PROGMEM char VARIABLE_STRINGS[30][20] =
{
	"Some Example\0",        //shortened version
	"some other\0",
	"another one\0"
};

So far so good. I can print all my chars by "Serial.print(VARIABLE_STRINGS[X][Y]);"
As i tried to iterate-print a string, i get problems.
My first thought was: "gonna be easy, just use "Serial.print(VARIABLE_STRINGS[X]);"

Which apparently returns me some gibberish of other parts of the memory i sometimes even recognize, but are outside of the char arrays memory.

It gets weirder. If i try to just print a single char from the array by telling it its X and Y to look, it returns the char perfectly fine. Once i put it in a loop and iterate it, it just returns random memory values.

Serial.print(VARIABLE_STRINGS[0][0]); // works

//------------------------------------------------

for (int i = 0; i < Var1; i++){               // does not work, returns
     for (int j = 0; j < Var2; j++){         // "random" memory-data
           Serial.print(VARIABLE_STRINGS[i][j]);
     }
}

The Serial is working fine, everything is printed the intended way, only my 1D-CHAR-ARRAY copied from 2D-CHAR-ARRAY wont print.

Weirder: i can even use "strcasecmp" to compare them and get the right results, which shows me that the variables are set alright, i guess.

So the problem might have to be in me trying to Serial.print(); it... but what am i doing wrong?

Thanks for help in advance

Felix

2

If you only want to print the messages

const PROGMEM char VARIABLE_STRINGS[][20] =
{
  "Some Example",
  "some other",
  "another one"
};

void setup() {
  Serial.begin(115200);
  for (byte i = 0; i < sizeof(VARIABLE_STRINGS) / sizeof(VARIABLE_STRINGS[0]); i++) {
    Serial.println((__FlashStringHelper*)VARIABLE_STRINGS[i]);
  }
}

void loop() {}

Some Example
some other
another one

Here is some documentation about PROGMEM avr-libc: <avr/pgmspace.h>: Program Space Utilities

3

Thank you VERY MUCH!

case closed

4

I post just to say... THANKS A LOT FROM ME TOO!