Warning when compiling Arduino code using CircuitPyton

[iCowboy]

Hi everyone,

Newbie to the Playground - though loving its potential. Hopefully this is a simple fix and an idiocy on my part. I did a search and couldn't find anyone posting this question - but sorry if it is a repeat.

I want to read the temperature from the built in sensor using the Adafruit_CircuitPlayground.h library, but each time I include a line to do so, the Arduino compiler throws a series of warnings:

/Users/mike/Library/Arduino15/packages/arduino/tools/arm-none-eabi-gcc/7-2017q4/bin/../lib/gcc/arm-none-eabi/7.2.1/../../../../arm-none-eabi/bin/ld: warning: changing start of section .bss by 4 bytes
/Users/mike/Library/Arduino15/packages/arduino/tools/arm-none-eabi-gcc/7-2017q4/bin/../lib/gcc/arm-none-eabi/7.2.1/../../../../arm-none-eabi/bin/ld: warning: changing start of section .bss by 4 bytes
/Users/mike/Library/Arduino15/packages/arduino/tools/arm-none-eabi-gcc/7-2017q4/bin/../lib/gcc/arm-none-eabi/7.2.1/../../../../arm-none-eabi/bin/ld: warning: changing start of section .bss by 4 bytes
/Users/mike/Library/Arduino15/packages/arduino/tools/arm-none-eabi-gcc/7-2017q4/bin/../lib/gcc/arm-none-eabi/7.2.1/../../../../arm-none-eabi/bin/ld: warning: changing start of section .bss by 4 bytes
/Users/mike/Library/Arduino15/packages/arduino/tools/arm-none-eabi-gcc/7-2017q4/bin/../lib/gcc/arm-none-eabi/7.2.1/../../../../arm-none-eabi/bin/ld: warning: changing start of section .bss by 4 bytes
Sketch uses 38260 bytes (14%) of program storage space. Maximum is 262144 bytes.
Global variables use 4248 bytes (12%) of dynamic memory, leaving 28520 bytes for local variables. Maximum is 32768 bytes.

The code *IS* compiling, but I can't see what the cause of the warning can be. It is definitely something to do with the temperature() command, as this minimal program throws the warning as does the Hello_Temperature example - but programs like the blink and fidget spinner do not:

Code: Select all

#include <Adafruit_CircuitPlayground.h>

float temp;

void setup() {
  CircuitPlayground.begin();
}

void loop() {
  temp = CircuitPlayground.temperature();
  delay(500);
}

I'm sure I'm doing something wrong, but I can't see it for the life of me.

(Running Arduino 1.8.13 and Adafruit Circuit Playground 1.11.3 on MacOS 11.6).

Thank-you in advance,

Mike.

[adafruit_support_bill]

warning: changing start of section .bss by 4 bytes

The bss is a section of memory reserved for statically allocated variables. Some processors require certain data types to be aligned on certain byte boundaries. For example a 64 bit 'double' may need to be aligned on an even 8-byte boundary. So the linker is warning you that it is making that adjustment. Nothing to really worry about - other than the fact that it ends up taking a bit more memory to do so.

[iCowboy]

Thank-you! I was hoping it was nothing serious - but that scary red text did make me worry.

I can press on.

Thank-you for the very quick response.

Mike.