Code from Nano not running on Leonardo and which Arduinos using Atmega328?

Using Arduino Programming Questions
#1

Hi,

I am wondering which are the Arduinos using the Atmega328 since i have code already for the Arduino Nano and porting them to certain Arduinos using a different microcontroller is being problematic since the registers don't seem to be compatible.

Here is the list of boards that i have found using the Atmega328.

  • UNO
  • Pro Mini
  • Nano
    Am i missing any?

And somehow, in the Arduino IDE when i'm compiling my code, i selected the MEGA and it worked?! The MEGA uses the ATmega2560. But if i try to compile the same code for the Leonardo (i really need the extra serial port), i get the following error in the Arduino IDE:

'TCCR2A' was not declared in this scope
'TCCR2B' was not declared in this scope
'TIMSK2' was not declared in this scope
etc...

So, i suppose that i have no choice but to rewrite the code, if i want to run the same Arduino Nano compatible code on the Leonardo which uses the ATmega32u4 microcontroller?

#2

For the official Arduino's that's all I think.

But want is using the non-portable code? Is it a library or your code? In case of the last, why?

And why do you need two serial ports?

#3

If you want to maintain compatibility of the code with different boards, you can use compiler directives to selectively compile different code for the different boards, such as:

#if defined(__AVR_ATmega32U4__)
//code specific to atmega32u4 board
#endif

#if defined(__AVR_ATmega328P__)
//code specific to atmega328 board
#endif

#if defined(__AVR_ATmega2560__)
//code specific to atmega2560 board
#endif

#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega2560__)
//code for atmega328 or atmega2560 boards
#endif
#4