The short answer is , but there is a major catch: you cannot retrieve the original C++ (.ino) source code with your comments and variable names. Instead, you will download a compiled HEX file —the machine-level instructions the processor actually understands. Summary of What is Possible
Check the /tmp/ directory for folders named arduino_build_XXXXXX . download code from arduino board
If the source code is truly gone, you can use a command-line tool called (which comes bundled with the Arduino IDE) to read the flash memory. The short answer is , but there is
You can download the HEX file and upload it to another identical Arduino to create a perfect "clone". If the source code is truly gone, you
Search for a file with the .ino.cpp extension. If you find it, you have successfully recovered your source code without needing to touch the board. Step 2: Downloading the HEX File via AVRDUDE
Before attempting a complex HEX download, check if your computer still has a copy of the original source code in its . The Arduino IDE stores a nearly-original version of your code during compilation: