APN issue

[jlcook83]

While trying to set APN information such as:

fona.setGPRSNetworkSettings(F("internet.com"), F("wapuser1"), F("wap"));

the following compile error occurs

Arduino: 1.5.6-r2 (Mac OS X), Board: "Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)"

/Applications/Arduino.app/Contents/Resources/Java/hardware/tools/avr/bin/../lib/gcc/avr/4.3.2/../../../../avr/lib/avr6/crtm2560.o: In function __vector_default': (.vectors+0xcc): relocation truncated to fit: R_AVR_13_PCREL against symbol__vector_51' defined in .text section in /Applications/Arduino.app/Contents/Resources/Java/hardware/tools/avr/bin/../lib/gcc/avr/4.3.2/../../../../avr/lib/avr6/crtm2560.o

The code compiles fine when the last part of the call (password field) is changed to at least 4 characters long.. and MUST contain a space. Example:
fona.setGPRSNetworkSettings(F("internet.com"), F("wapuser1"), F("wap 1"));

Unfortunately i need the password to be 3 chars and NO spaces...

I can't seem to understand the problem to fix it...

[tdicola]

This is a tricky one because it's likely from a bug in the compiler (see this thread for a little more background and info: arduino/Arduino#1071). Unfortunately it's not related to the FONA library and is a side affect of the code & flash memory taking up enough space to slightly change the linker's behavior.

One thing to try as a workaround, can you see if using Arduino 1.5.8 beta and it's newer compiler works? This likely has a lot more bug fixes and optimizations that should reduce the change of these kinds of issues occuring.

Another workaround is to add or remove variables to change the flash memory usage enough that it doesn't trigger the linker bug. Try the Arduino 1.5.8 version first though as that should fix the issue at the source.