Serial.println()

[thelearner]

Hello,
I have a standalone device with ATtiny85 MCU running Arduino firmware. In the firmware there are serial.println() functions that write its status to the serial port. Since it is a standalone device serial port is not connected to a system or to any other device.
Will this affect the device in any way in the long run?

TIA

Regards,
thelearner

[sleemanj]

No, as long as nothing is connected to the serial pins, no problem.

[Rick Law]

One thing to consider...  Why would you want to bring in the serial library (which is not small) and add complication.

I would think, eliminating those serial related codes with #define then #if to block them out would be a far superior way to handle them rather than leaving the serial.whatever() in place relying (hoping) it would do no harm.

[brucehoult]

One thing to consider...  Why would you want to bring in the serial library (which is not small) and add complication.

Not all that much, even for an ATTiny85. I don't have the ATTiny package installed on this machine, but it won't be much different to the 328.

Adding Serial.begin(9600) to a sketch adds 994 bytes of code.
Serial.println() of an int adds 98 bytes more.
Serial.println() of a string instead adds 36 bytes.
Printing both an int and a string adds 104 bytes [1] over just Serial.Begin() or 1098 bytes over the sketch with no use of Serial at all.

Those numbers include the call to the library as well as the library code.


[1] that's so little more than just printing an int that I expect it's not actually adding any more library code,  and the 6 bytes difference is simply the call to the string print function.

ATTiny85 has 8K of program space, so using 1K for Serial is probably usually not a big deal. You probably want to have the ability to add debug printing if necessary, so leaving that flash space empty in production deployments doesn't actually save anything.