How do I wipe the memory clean and start over?

I uploaded programing to my UNO R3 ATmega328P Development Board and everything was working great, now I am having issues and want to wipe the memory/programing that is on it now. Can someone help me out on how I do that?


I have also tried that. The program I am using is called iflag: iFLAG -

As I said, when I us the software to program it, all is good but if I change the com ports and try to reprogram, it just doesn't work. so I was hoping there was a away to wipe the memory clean and start over again.

The computer see the Uno board, sees that its in a new port and the Arduino software also see the board in the "ports" tab... when I run serial monitor on it.. I can see that the computer and the board are talking to each other, but the program still will not work.


There are three types of memory on your Uno:

  • SRAM: This is reset every time you unplug the Uno, press the reset button, or upload a sketch.
  • Flash: This is reset every time you upload a sketch.
  • EEPROM: This memory persists through power outages, resets, and uploads. However, the iflag sketch does not use EEPROM (though they do have an #include directive for the EEPROM library for no reason) so EEPROM is not of concern to you.

Therefore, the solution to your problem does not lie with “wiping the memory clean”. If you want help with the problem, you should provide more details on what you mean by “the program still will not work”.

It sounds like OP has the serial port open when he’s trying to upload a new sketch.
The error messages in the IDE will tell him the serial port isn’t available / already in use.