Arduino: Fixing "Serial Port in Use"

Mon, 08 Oct 2012 09:46:16 +0000

Here’s a couple of quick tips to get around the Arduino IDE error message “Serial Port in Use.” These mostly apply to OSX, but since it is UNIX based, they may make sense for Linux as well.

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Applies to: OSX, Linux.

The check to see if another process (like a previous run of avrdude) is holding the serial port open is easy on both Linux and OSX. Just open a terminal and run the command: lsof. The command will report back all files that are currently open by the operating system. UNIX-based operating systems do everything through files, so this command is useful to see what is keeping a serial device open. Since lsof gives a list of everything that’s open, and there are a lot of “files”, use grep to only list what is relevant.

Linux on Bald Engineer

Arduino: Fixing "Serial Port in Use"

List Open Files