CODEWITHSUNDEEP
arduinoserial-portarduino-uno
Patrick Dahlin
Patrick Dahlin

Reputation: 286

Arduino com port keeps getting busy

I have got an Arduino Uno R3 on which I have an accelerometer that I'm playing a bit with. This setup has worked for quite a while now, everything working from uploading to checking the serial output.

Today I started having problems with the com port reporting busy or not connected at all. When I use the default IDE it cant find the arduino at all but when I use a modded IDE (Arduino ERW 1.0.5) seems to find the port to communicate on but it reports it being busy.

I have reinstalled the driver like 5 or 6 times now and searched for any other driver that might work but they wont change anything. I have also checked that my pc actually detects the arduino which it does, it is listed among the COM ports on Device Manager. I also tried changing the Com port from COM3 to COM4 and still it worked for like 3 uploads and then the COM port kinda "disappeared" from the serial port list on the IDE.

EDIT: Weirdly, after closing some programs that seem to have to do with serial communication it works. I have to look into what I close and when.

EDIT2: For now it seems that processing sometimes didnt close properly when not using the stop button on the processing application which then didnt close the connection to the arduino. I havent had any problems since I started to use the Stop button on processing.

Win 8.1 Latest driver and IDE(an modded IDE called Arduino ERW 1.0.5 seem to work a bit better but have the same issues)

One thing I noticed is that if I press the reset button when it starts again it wont send anything through serial, is it defaulting to the Blink program after a reset or what?

Upvotes: 1

Views: 12908

Answers (3)

ntomazin
ntomazin

Reputation: 21

For anyone who is struggling with this, you have to give again rw rights to ttyACM0

sudo chmod a+rw /dev/ttyACM0

after that I was able to open the serial port.

Upvotes: 1

user8917573
user8917573

Reputation:

For those getting the "port busy" error while connecting Arduino and Process, one fix is to close the serial monitor in Arduino.

Upvotes: 1

Patrick Dahlin
Patrick Dahlin

Reputation: 286

I found the problem being in Processing itself, on win 8.1 the P3D option for 3D renderer seems to leave the java process open after closure which causes the serial port to be busy even after the main window is closed.

I simply fixed it by using OPENGL instead of P3D which didn't change anything visibly so I'm fine with it.

Upvotes: 0

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