System cannot find file specified.


I'm pretty new to using microcontrollers so bear with me.

I'm using an Uno rev3 to flash my 3D printer and I'm getting the error message:

avrdude: ser_open(): can't open device "\.\COM1": The system cannot find the file specified.

It's worked before and I'm not sure what might have changed.

So far I have checked the COM port in the device manager, reinstalled drivers, tried various cables and ports, restarted the IDE and checked preferences.txt but I'm getting the same error every time.

Is there something obvious that I'm missing?

I'm running Windows 7 and version 1.8.7 of the IDE.


Very very unlikely to be COM 1 or 2 on a windows machine.

Double check in device manager what appears when you just plug the board in by itself.

Device Manager says COM1. I've changed it to COM3 to see what happens and it's thrown up this instead:

avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: Expected signature for ATmega1284P is 1E 97 05
Double check chip, or use -F to override this check.

I guess the wrong COM port was the issue but it's found something else it doesn't like.

Thanks for pointing me in the right direction.

That error indicates you're trying to upload to something based on 1284p, but it's talking to the bootloader of the Uno, and (correctly) not uploading to it.

What exactly are you trying to do, and how is everything set up? How is the Uno connected to the 3d printer controller, which is presumably based on a 1284p?

I'm trying to flash a bootloader to the printer.

I was using jumper cables from the Uno to the printer board. The printer is an Ender 3 which I understand uses a 1284p.

I unplugged and plugged everything back in and restarted the IDE and it's worked this time so whatever was upsetting it is beyond me. Very likely I had my wires mixed up.