I have an arduino uno. Whenever I try to upload code to the arduino I get this error.

avrdude: ser_open(): can't open device "/dev/cu.usbserial-AL01EI7I": Device not configured 

ioctl("TIOCMGET"): Inappropriate ioctl for device Problem uploading to board. 
See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
  • What OS are you on? Do you have the necessary drivers installed?
    – John K
    Dec 26, 2015 at 8:45

1 Answer 1


The error message is telling you that avrdude failed to open the device and read the modem status (basically the information about whether a device is present and ready on a serial line). The most likely causes of this are:

  1. Using the wrong serial port (Tools > Port in the Arduino IDE).
  2. The IDE not recognizing the board.
  3. Using a power only USB cable.

The Arduino IDE seems to remember the device that your board was last connected through, but on some Unix flavored OSes the device name depends, in part, on method of connection – which port, hub or no hub, etc. So if you change the board or the port you plug it into, the name changes.

So, the very first thing to do is to look under Tools > Port in the Arduino IDE to see if there is another device present. Also confirm that you're using a USB cable with data wires. There are "power only" USB cables…

Failing that, check to see if the OS sees the board. On OS X you would go to the Apple menu and choose About this Mac and then look at at the System Report to see what devices have been detected on your USB busses. I'd be surprised if there wasn't something similar on Linux (and Windows too for that matter). If you're comfortable on the command line you could look in /dev for devices with similar names.

If the board is present, but not seen by the Arduino IDE, try restarting the IDE and/or plugging and unplugging the USB cable. Sometimes it helps to plug the cable into a different port.

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