sudo usermod -aG dialout $(whoami)
Q:
[200244.564482] usb 1-2: usbfs: interface 0 claimed by ch341 while 'brltty' sets config #1
A: sudo apt-get autoremove brltty
Q:
avrdude: ser_open(): can't open device "/dev/ttyUSB0": Permission denied
A: ll /dev/ttyU*; chmod a+rw /dev/ttyU*; ll /dev/ttyUSB*
Q: avrdude: stk500_recv(): programmer is not responding
A:Tools > Processor > ATmega328P (Old Bootloader).
http://cxem.net/arduino/arduino52.php
http://cxem.net/arduino/arduino53.php
http://cxem.net/arduino/arduino64.php
http://cxem.net/arduino/arduino50.php
http://www.xakep.ru/magazine/xa/122/100/1.asp
NRF24L01 Transceiver and Arduino
electronics:
adafruit.com
http://www.wayengineer.com/
Troubleshooting USB and the grayed out Serial Port
When I got the Arduino 1.0.1 update, “Serial Port” was grayed out in the tools menu. Running arduino as root ( sudo ./arduino) resolved the issue, but it’s not an acceptable solution. In my case, serial port was grayed out because my user didn’t have permission to read and write to the device.I added my user to the dialout group with the command sudo usermod -a -G dialout mark . Usually, that would have fixed it but iserial port was still grayed out.
Changing the permissions on /dev/ttyACM0 to world readable and writeable fixed the grayed out serial port. I ran sudo chmod a+rw /dev/ttyACM0 and the serial port menu worked again.
I’ve noticed that running programs that send lots of data over USB can cause issues with the arduino programming software, making it give errors while uploading code. Holding down the reset button fixed my upload and USB errors in most cases.