Andrey Mikhalchuk’s Blog

• Build the sketch
• Find /tmp/build*.tmp folder. There should be one, if you see multiple then rm -rf /tmp/build*.tmp and rebuild the sketch. Only one build folder should be in the /tmp (for simplicity
• run avr-size /tmp/build*.tmp/[sketch_name].elf
• sum of data and bss values if the number you’re looking for

I was recently compiling some Arduino code with NewSoftSerial and got hit by infamous “Error: register r24, r26, r28 or r30 required” error. NewSoftSerial is a great library and those using older avr-gcc compiler enjoy it alot. Problem is the newer gcc doesn’t like one nasty error in the code and here is how to fix it …