Sometimes you need to clear, wipe, erase, - whatever you want to call it - to run code on it from a different source, such as the Processing platform, and you don't want to run the code currently uploaded code. You've tried to upload a blank sketch and you get this Error Message:
core.a(main.cpp.o): In function `main':
C:\Program Files\Arduino\hardware\arduino\cores\arduino/main.cpp:11: undefined reference to `setup' C:\Program Files\Arduino\hardware\arduino\cores\arduino/main.cpp:14: undefined reference to `loop'
Here how to do it.
Step 1: Remove All Unnecessary Hardware.
Remove all the unnecessary hardware and connect the Arduino to the computer.
(Yes, I'm using a spin off of the Arduino. It's still the same concept.)
(To get a RedBoard [ the spin off ] go here.)
Step 2: Upload the Sketch
Upload the attached sketch.