Just defining a function can render another function useless?

Projects Programming
1

Once again I encountered a strange problem, which makes no sense for me.
In the Setup-Routine I'm calling a function which checks a database if its available. No problems with that.
But now I've defined a new function and without actually calling it anywhere, the ckeck-db-function hangs on startup (No compilation error). I've debugged the new function to that point:

Serial.print("...");

If that line is commented out, everything works fine.
Just a reminder: The new function was only defined, not even called anywhere (It is supposed to be called before check-db). How can that be?

2

How can that be?

Without seeing your code, I'm going to guess that you are running out of memory.

POST YOUR CODE!

3

Running out of SRAM was my first guess, too.

4

I've debugged the new function to that point:
Code: [Select]

Serial.print("...");

Didn't you mean Serial.print(F("...")); ?

5

But now I've defined a new function and without actually calling it anywhere ...

Why did you define a function without calling it? Wasn't that a waste of time?

6

I've waited for that question :grinning:
Sure I had called the function. But when the sketch didn't work any longer I removed the reference. It still didn't work so I removed the definition too - that finally did it.

POST YOUR CODE!

I will. But I'm currently not at my PC...

7

Here is the code. It might be a little unstructured but I'm not finished yet...
I'm getting more and more sure that it's really getting out of memory. It must be the EEPROM-crc check.

zks.zip (5.06 KB)

8

I'm getting more and more sure that it's really getting out of memory.

10 lines into the code, and I am positive:

String myHost, myUser, myDB, myPass;

//Python Einstellungen
const String pyPath = "/usr/bin/python";
const String pyScript = "/skripte/sqlexec.py";

//USB-Device
const String usbDevice = "/dev/input/event1";
const String deviceID = "05f9:2206";
const String usbHub = "058f:6254";

There REALLY is no reason to piss away memory like that. char * will work just as well.

void DisplayText(String Line1, String Line2)

This function REALLY does not need to take Strings.

There should be a means of displaying data that can accommodate the use of the F() macro, so that you can do:
DisplayText(F("Bitte Konfigu-"), F("ration pr\365fen."));

9 
 DisplayText(F("Bitte Konfigu-"    "ration pr\365fen."));
10

Oh nooooo! Shame on me :-[
That happens when you do your daily business with Visual Basic and C# - No thoughts about limited resources...
Ok I will revise my code with priority on memory usage. Thank you guys :slight_smile:

11

It happens to everyone that moves from PCs with 1 GB of RAM, to get a shock to find they have 2 KB of it.