Permission denied on /dev/ttyACM0

In a terminal, with the board plugged in, enter.
ls -l /dev/ttyACM*, this will show the group that has access to the port.

Example: crw-rw-r-- 1 root dialout ... /dev/ttyACM0, root is owner, dialout is the group with access.

Entering the command, groups, in a terminal will show the groups you belong to.

sudo adduser YourUserName GroupToJoin Will fix things if you need to join a group, logout and login after you run adduser.

modem-manager can also be a problem -- most people just remove the package.

2 Likes

try the following command

sudo chmod a+rw /dev/ttyACM0

--

Check this link for more info Installing Arduino IDE in Linux - YouTube

28 Likes

tf68:
In a terminal, with the board plugged in, enter.
ls -l /dev/ttyACM*, this will show the group that has access to the port.

Example: crw-rw-r-- 1 root dialout ... /dev/ttyACM0, root is owner, dialout is the group with access.

Entering the command, groups, in a terminal will show the groups you belong to.

sudo adduser YourUserName GroupToJoin Will fix things if you need to join a group, logout and login after you run adduser.

this did it for me as i ended up here with same problem as OP. i always forget this set of commands and have this sort of trouble every time i try to hook up a 3d printer to a fresh linux install. I ended up here now from trying to program an Arduino Uno.

THANK YOU!

anilkunchalaece:
try the following command

sudo chmod a+rw /dev/ttyACM0

--

Check this link for more info https://www.youtube.com/watch?v=Z2hlBbZu3CI

Thank you! Worked for me!

3 Likes

anilkunchalaece:
try the following command

sudo chmod a+rw /dev/ttyACM0

--

Check this link for more info https://www.youtube.com/watch?v=Z2hlBbZu3CI

Working on Ubuntu 18.04.1 LTS on an arduino UNO r3 via USB, and this fixed the issue for me.

Thanks Anil!

Here's what I think the fix is doing: chmod is a utility that modifies privileges. What this command is doing is changing privileges for /dev/ttyACM0, the port we're trying to write to the arduino with. We're running chmod a+rw. The "a" signifies that we're in a-mode, which modifies all users, and the "+rw" means we "+" (add) "rw" (read and write permissions).

1 Like

I had the same problem, I try to load a Blink test program in an generic Arduino UNO with a laptop with Linux Ubuntu 16.04 LTS, but when i change the permissions with the command "sudo chmod 777 /dev/ttyACM0" (the ttyACM0 is the USB port were I had connected the Arduino board) the problem still present. someone know what will be the problem? I try even to change the group for my user, wit the command "sudo usermod -a -G dialout userA".

Hi!

I have this problem:

avrdude: usbdev_open(): cannot open device: Permission denied
avrdude: jtag3_open_common(): Did not find any device matching VID 0x03eb and PID list:

Anyone have any ideas how to solve this? Permissions looks like this:

crw-rw-rw- 1 root dialout 166, 0 huhti 4 12:21 /dev/ttyACM0

Br.
Kimmo

Hi!

Now I get this error:

avrdude: usbdev_open(): WARNING: failed to set configuration 1: Device or resource busy
avrdude: WARNING: invalid value for unused bits in fuse "fuse5", should be set to 1 according to datasheet
This behaviour is deprecated and will result in an error in future version
You probably want to use 0xcd instead of 0xc9 (double check with your datasheet first).

Br.
Kimmo

anilkunchalaece:
try the following command

sudo chmod a+rw /dev/ttyACM0

--

Check this link for more info https://www.youtube.com/watch?v=Z2hlBbZu3CI

Thank you! Worked for me!

Just set current user to belong to "dialout" group which is the one who members are allowed to access ports.

Run follwing:

sudo adduser yourUserName dialout

then relog to take effect

(Ubuntu 18.04)

i tried both the solutions and they worked but when i unplug my board and replug it,i have to run the command again...
is there a permanent fix to it

The issue with the permissions for /dev/ttyACM0 can be permanantly solved by adding yourself to the dialout group. You will have to logout and then log back in before the group change is recognized.
You can do this with sudo usermod -a -G dialout $USER

Resource
It worked for me.

You can solve it by adding yourself to the dialout group in Debian-based Linux, or uucp group in Arch Linux.

sudo usermod -a -G dialout $USER

OR

sudo usermod -a -G uucp $USER

For changes to take effect, simply logout and re-login. You can now compile and write to Arduino via the IDE.

1 Like

I'm having exactly the same issue. I have done all of the above. I am a member of the "dialout group", but I still get the error message:

"avrdude: ser_open(): can't open device "/dev/ttyS0": Permission denied"

I am trying to upload to my 3D printer Mega 2560. I am connecting the Mega from the USB port of my computer. The Mega 2560 is working as I have moved the steppers around and done some calibration as well through the graphics controller. The problem arose after I changed my computer. My operating system is Ubuntu 18.04 LTS.

Any help or advice will be greatly appreciated.

Thanks in advance

In Linux, the Arduino serial port is named /dev/ttyACMx where x starts at 0. If using a clone board, the serial port name may be /dev/ttyUSBx where x starts at 0.

Arduino: 1.8.5 (Linux), Board: "Arduino/Genuino Uno"

/snap/arduino-mhall119/5/arduino-builder -dump-prefs -logger=machine -hardware /snap/arduino-mhall119/5/hardware -tools /snap/arduino-mhall119/5/tools-builder -tools /snap/arduino-mhall119/5/hardware/tools/avr -built-in-libraries /snap/arduino-mhall119/5/libraries -libraries /home/doncun/snap/arduino-mhall119/5/Arduino/libraries -fqbn=arduino:avr:uno -ide-version=10805 -build-path /tmp/arduino_build_659730 -warnings=all -build-cache /tmp/arduino_cache_412874 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=/snap/arduino-mhall119/5/hardware/tools/avr -prefs=runtime.tools.avr-gcc.path=/snap/arduino-mhall119/5/hardware/tools/avr -prefs=runtime.tools.avrdude.path=/snap/arduino-mhall119/5/hardware/tools/avr -verbose /home/doncun/Documents/Arduino/Blink_led/Blink_led.ino
/snap/arduino-mhall119/5/arduino-builder -compile -logger=machine -hardware /snap/arduino-mhall119/5/hardware -tools /snap/arduino-mhall119/5/tools-builder -tools /snap/arduino-mhall119/5/hardware/tools/avr -built-in-libraries /snap/arduino-mhall119/5/libraries -libraries /home/doncun/snap/arduino-mhall119/5/Arduino/libraries -fqbn=arduino:avr:uno -ide-version=10805 -build-path /tmp/arduino_build_659730 -warnings=all -build-cache /tmp/arduino_cache_412874 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=/snap/arduino-mhall119/5/hardware/tools/avr -prefs=runtime.tools.avr-gcc.path=/snap/arduino-mhall119/5/hardware/tools/avr -prefs=runtime.tools.avrdude.path=/snap/arduino-mhall119/5/hardware/tools/avr -verbose /home/doncun/Documents/Arduino/Blink_led/Blink_led.ino
Using board 'uno' from platform in folder: /snap/arduino-mhall119/5/hardware/arduino/avr
Using core 'arduino' from platform in folder: /snap/arduino-mhall119/5/hardware/arduino/avr
Detecting libraries used...
"/snap/arduino-mhall119/5/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-I/snap/arduino-mhall119/5/hardware/arduino/avr/cores/arduino" "-I/snap/arduino-mhall119/5/hardware/arduino/avr/variants/standard" "/tmp/arduino_build_659730/sketch/Blink_led.ino.cpp" -o "/dev/null"
Generating function prototypes...
"/snap/arduino-mhall119/5/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-I/snap/arduino-mhall119/5/hardware/arduino/avr/cores/arduino" "-I/snap/arduino-mhall119/5/hardware/arduino/avr/variants/standard" "/tmp/arduino_build_659730/sketch/Blink_led.ino.cpp" -o "/tmp/arduino_build_659730/preproc/ctags_target_for_gcc_minus_e.cpp"
"/snap/arduino-mhall119/5/tools-builder/ctags/5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "/tmp/arduino_build_659730/preproc/ctags_target_for_gcc_minus_e.cpp"
Compiling sketch...
"/snap/arduino-mhall119/5/hardware/tools/avr/bin/avr-g++" -c -g -Os -Wall -Wextra -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -flto -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-I/snap/arduino-mhall119/5/hardware/arduino/avr/cores/arduino" "-I/snap/arduino-mhall119/5/hardware/arduino/avr/variants/standard" "/tmp/arduino_build_659730/sketch/Blink_led.ino.cpp" -o "/tmp/arduino_build_659730/sketch/Blink_led.ino.cpp.o"
Compiling libraries...
Compiling core...
Using precompiled core
Linking everything together...
"/snap/arduino-mhall119/5/hardware/tools/avr/bin/avr-gcc" -Wall -Wextra -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p -o "/tmp/arduino_build_659730/Blink_led.ino.elf" "/tmp/arduino_build_659730/sketch/Blink_led.ino.cpp.o" "/tmp/arduino_build_659730/../arduino_cache_412874/core/core_arduino_avr_uno_5ae566d2b74f299eedfb0fc6b9173d06.a" "-L/tmp/arduino_build_659730" -lm
"/snap/arduino-mhall119/5/hardware/tools/avr/bin/avr-objcopy" -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0 "/tmp/arduino_build_659730/Blink_led.ino.elf" "/tmp/arduino_build_659730/Blink_led.ino.eep"
"/snap/arduino-mhall119/5/hardware/tools/avr/bin/avr-objcopy" -O ihex -R .eeprom "/tmp/arduino_build_659730/Blink_led.ino.elf" "/tmp/arduino_build_659730/Blink_led.ino.hex"
Sketch uses 1092 bytes (3%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
/snap/arduino-mhall119/5/hardware/tools/avr/bin/avrdude -C/snap/arduino-mhall119/5/hardware/tools/avr/etc/avrdude.conf -v -patmega328p -carduino -P/dev/ttyUSB0 -b115200 -D -Uflash:w:/tmp/arduino_build_659730/Blink_led.ino.hex:i

avrdude: Version 6.3, compiled on Jan 17 2017 at 11:00:16
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "/snap/arduino-mhall119/5/hardware/tools/avr/etc/avrdude.conf"
User configuration file is "/home/doncun/snap/arduino-mhall119/5/.avrduderc"
User configuration file does not exist or is not a regular file, skipping

Using Port : /dev/ttyUSB0
Using Programmer : arduino
Overriding Baud Rate : 115200
avrdude: ser_open(): can't open device "/dev/ttyUSB0": Permission denied

avrdude done. Thank you.

Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
Error opening serial port '/dev/ttyUSB0'. Try consulting the documentation at Arduino Playground - All
processing.app.SerialException: Error opening serial port '/dev/ttyUSB0'. Try consulting the documentation at Arduino Playground - All

Hi Folks,
New here.This page was helpful. Tried the

sudo adduser yourUserName dialout

and the upload worked. But then I got a new error message.
At the IDE program tools>board I missed the right board name.
Changed it and after that it works.
Thank You all.

try the following command

sudo chmod a+rw /dev/ttyACM0

worked for me

sudo chmod a+rw /dev/ttyACM0

I’m glad that command line fixed the problem for some but it didn't help me

Then I ran

sudo adduser yourUserName dialout

And the linux system reported that I’m already a member of dialout

Yet still on serial port in Arduino

“Serial port com1 not found”

sudo chmod a+rw /dev/ttyACM0 works for a single time

"sudo usermod -a -G dialout $USER" and "sudo usermod -a -G uucp $USER" neither work. still have to chmod everytime.

What am I missing? Obviously "USER" is changed to mine.
Thanks