Compilation Error: Undefined reference to main

Projects Programming
1 
c:/users/mdmee/appdata/local/arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/../lib/gcc/avr/7.3.0/../../../../avr/lib/avr5/crtatmega328p.o:(.init9+0x0): undefined reference to `main'
collect2.exe: error: ld returned 1 exit status

exit status 1

Compilation error: exit status 1

This is my code, literally the default blink example:

#include <Arduino_BuiltIn.h>

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);  // turn the LED on (HIGH is the voltage level)
  delay(1000);                      // wait for a second
  digitalWrite(LED_BUILTIN, LOW);   // turn the LED off by making the voltage LOW
  delay(1000);                      // wait for a second
}
2

Welcome to the forum

Which Arduino board are you using and which board have you got selected in the IDE ?

3

Hi @meeran

welcome to the arduino-Forum.
Well done to post the error-message and the code as a code-section.

You should provide much more detailed information about the compile-process.
Read this 3 minutes tutorial to learn how to adjust the Arduino-IDE to automatically create alls the detail-information

4

Using Arduino UNO and thats the one selected in the IDE

5

That is not the default Blink example

Comment out that first #include

6

If I select Arduino Uno in my IDE and compile your code as posted in post #1
it does compile.

So there must be something else wrong.

You can now waste hours, days and weeks by posting too short new postings or take a single time 5 minutes to read and then follow this tutorial.

This will

AUTOMATICALLY

create all the details that you do not know yet to analyse to find the error

7

Your compile error is in the AVR boards code. Either your install went bad, or a HDD soft fail. In either case just do a re-install of the IDE. If this persists, you need to delete the entire Arduin15 folder and any other hidden Arduino folders (at least one)

8

Already tried

9

alright ill do this

10

These are all the details


FQBN: arduino:avr:uno
Using board 'uno' from platform in folder: C:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6
Using core 'arduino' from platform in folder: C:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6

Detecting libraries used...
C:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR -IC:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6\cores\arduino -IC:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6\variants\standard C:\Users\mdmee\AppData\Local\arduino\sketches\72692CF9A2E9E385C9B7228DC9D46C74\sketch\Blink.ino.cpp -o nul
Generating function prototypes...
C:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR -IC:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6\cores\arduino -IC:\Users\mdmee\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6\variants\standard C:\Users\mdmee\AppData\Local\arduino\sketches\72692CF9A2E9E385C9B7228DC9D46C74\sketch\Blink.ino.cpp -o C:\Users\mdmee\AppData\Local\Temp\1600574688\sketch_merged.cpp
C:\Users\mdmee\AppData\Local\Arduino15\packages\builtin\tools\ctags\5.8-arduino11/ctags -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives C:\Users\mdmee\AppData\Local\Temp\1600574688\sketch_merged.cpp
Compiling sketch...
"C:\\Users\\mdmee\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-g++" -c -g -Os -Wall -Wextra -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -MMD -flto -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\\Users\\mdmee\\AppData\\Local\\Arduino15\\packages\\arduino\\hardware\\avr\\1.8.6\\cores\\arduino" "-IC:\\Users\\mdmee\\AppData\\Local\\Arduino15\\packages\\arduino\\hardware\\avr\\1.8.6\\variants\\standard" "C:\\Users\\mdmee\\AppData\\Local\\arduino\\sketches\\72692CF9A2E9E385C9B7228DC9D46C74\\sketch\\Blink.ino.cpp" -o "C:\\Users\\mdmee\\AppData\\Local\\arduino\\sketches\\72692CF9A2E9E385C9B7228DC9D46C74\\sketch\\Blink.ino.cpp.o"
Compiling libraries...
Compiling core...
Using precompiled core: C:\Users\mdmee\AppData\Local\arduino\cores\arduino_avr_uno_566c47d9f63672ddb7f5ae3fcfffff35\core.a
Linking everything together...
"C:\\Users\\mdmee\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-gcc" -Wall -Wextra -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p -o "C:\\Users\\mdmee\\AppData\\Local\\arduino\\sketches\\72692CF9A2E9E385C9B7228DC9D46C74/Blink.ino.elf" "C:\\Users\\mdmee\\AppData\\Local\\arduino\\sketches\\72692CF9A2E9E385C9B7228DC9D46C74\\sketch\\Blink.ino.cpp.o" "C:\\Users\\mdmee\\AppData\\Local\\arduino\\sketches\\72692CF9A2E9E385C9B7228DC9D46C74/..\\..\\cores\\arduino_avr_uno_566c47d9f63672ddb7f5ae3fcfffff35\\core.a" "-LC:\\Users\\mdmee\\AppData\\Local\\arduino\\sketches\\72692CF9A2E9E385C9B7228DC9D46C74" -lm
c:/users/mdmee/appdata/local/arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/../lib/gcc/avr/7.3.0/../../../../avr/lib/avr5/crtatmega328p.o:(.init9+0x0): undefined reference to `main'
collect2.exe: error: ld returned 1 exit status

exit status 1

Compilation error: exit status 1
11

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