Upload to Nano fails: 'avrdude: ser_open(): can't set com-state for "\.\COM6"'

[nizartheprogrammer]

Arduino: 1.8.16 (Windows 10), Board: "Arduino Nano, ATmega328P (Old Bootloader)"

`type or paste code here`

Sketch uses 924 bytes (3%) of program storage space. Maximum is 30720 bytes.

Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.

C:\Users\Lenovo\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/bin/avrdude -CC:\Users\Lenovo\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/etc/avrdude.conf -v -patmega328p -carduino -PCOM6 -b57600 -D -Uflash:w:C:\Users\Lenovo\AppData\Local\Temp\arduino_build_342375/Blink.ino.hex:i

avrdude: Version 6.3-20190619

     Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

     Copyright (c) 2007-2014 Joerg Wunsch



     System wide configuration file is "C:\Users\Lenovo\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/etc/avrdude.conf"



     Using Port                    : COM6

     Using Programmer              : arduino

     Overriding Baud Rate          : 57600

avrdude: ser_open(): can't set com-state for "\.\COM6"

avrdude done. Thank you.

An error occurred while uploading the sketch

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

[ptillisch]

Hi @nizartheprogrammer.

@nizartheprogrammer

avrdude: ser_open(): can't set com-state for "\.\COM6"

There were some previous reports of this "can't set com-state for ..." error occurring specifically when uploading to the boards that use the WCH CH340 USB chip (and apparently only specific batches of those chips). The problem only occurs when using the latest version of the CH340 driver.

The affected users have reported that doing a "roll back" to an older version of the driver was an effective workaround. You can give that a try.

I'll provide instructions:

1. Open this tutorial from SparkFun in your browser:
   https://learn.sparkfun.com/tutorials/how-to-install-ch340-drivers/all#drivers-if-you-need-them
   ⓘ We are using this tutorial as a source for an older version of the CH340 drivers. Generally I recommend only obtaining drivers from the manufacturer of the device, but WCH does not provide older versions of their drivers and SparkFun is trustworthy.
2. Click the "Windows (EXE)" link you see in red under the "Drivers (If You Need Them)" section of the tutorial.
3. Wait for the download to finish.
4. Run the downloaded CH341SER.EXE file.
5. A "User Account Control" dialog may now appear asking "Do you want to allow this app to make changes to your device?". Click the "Yes" button.
6. A "DriverSetup(X64)" dialog will appear. Click the "INSTALL" button in the dialog.
7. Wait for the driver installation to finish, as indicated by the appearance of a "Driver install success!" dialog.
8. Click the "OK" button in the "Driver install success!" dialog.
9. Click the X icon at the top right of the "DriverSetup(X64)" dialog to close it.
10. Close Arduino IDE if it is running.
11. Connect the Arduino board to your computer with a USB cable.
12. Open the Windows Device Manager.
13. Select View > Devices by type from the Device Manager menus.
14. Open the "View" menu.
15. If there is a ✓ to the left of the "Show hidden devices" menu item, click on "Show hidden devices" to disable it.
16. Open the "Ports (COM & LPT)" section of the Device Manager tree.
17. You should see a port identified as "USB-SERIAL CH340 (COMn)" under the "Ports (COM & LPT)" section (where "COMn" is some serial port e.g., COM4). Double click on that item.
    The "USB-SERIAL CH340 (COMn) Properties" dialog will open.
18. Select the "Driver" tab of the "USB-SERIAL CH340 (COMn) Properties" dialog.
19. You will see a "Roll Back Driver" button in the dialog. If it is not clickable, perform the following instructions:
    1. Click the "Update driver" button.
       An "Update Drivers Device - USB-SERIAL CH340 (COMn)" dialog will open.
    2. Click on "Search automatically for drivers" in the "Update Drivers Device - USB-SERIAL CH340 (COMn)" dialog.
    3. You should now see the driver installation wizard update the driver. Wait for the update to finish, as indicated by the message "Windows has successfully updated your drivers" in the dialog.
       It is possible you will instead see the message "The best drivers are already installed". If so, please stop following the instructions here and reply on the forum thread to let me know. I'll provide alternative instructions you can follow.
    4. Click the "Close" button in the "Update Drivers Device - USB-SERIAL CH340 (COMn)" dialog.
20. Click the "Roll Back Driver" button in the "USB-SERIAL CH340 (COMn) Properties" dialog.
    The "Driver Package rollback" dialog will open.
21. Click the radio button next to "My apps don't work with this driver" in the "Driver Package rollback" dialog .
22. Click the "Yes" button.
23. Click the "Close" button in the "USB-SERIAL CH340 (COMn) Properties" dialog.

Now start Arduino IDE again and repeat whatever you were doing before when you encountered that error before. Hopefully this time you will not encounter that "can't set com-state" error during the sketch upload.

[emjay_blng]

Hello,

I have the same problem and installed the driver as you showed in your instructions, but now I always get the following error when uploading a sketch to my arduino nano:

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xa0

I tried all of my ports.

After a failed attempt of uploading the little popup window always states:

Can you please help me further with this problem? I'm new to Arduino and better with the Uno, but I have to use the Nano for a mechanical engineering project in university.

Thank you and greetings!

[emjay_blng]

Update: I also tried all of the available bootloaders (as I read in other posts to this topic) without any success!

[ptillisch]

Hi @emjay_blng. This error might be caused by having the wrong port selected from the Tools > Port menu in Arduino IDE.

I'm a bit suspicious of your port selection because in the first screenshot you shared the error message says "COM4", but then in the second screenshot it shows that you have COM5 selected from the Tools > Port menu in Arduino IDE.

Please perform this experiment to verify that the port you have selected is your Arduino board:

1. Disconnect the USB cable of the Arduino board from your computer.
2. Select Tools > Port from the Arduino IDE menus.
3. Take note of the ports, if any, listed in the menu.
4. Close the Tools menu.
   The ports list is only updated when the Tools menu is re-opened, so this step is essential.
5. Connect the Arduino board to your computer with a USB cable.
6. Select Tools > Port from the Arduino IDE menus. - If a new port is listed in the menu, that is the port of your Arduino board.

Select that port from the menu and try uploading again.

If the upload still fails, or if no new port appeared after you plugged the Arduino board into your computer, add a reply here to let us know and we'll investigate the problem further.