Since I'm researching on this topic for quite a while, read all the old messages here in the forum it's probabely not something trivial like not being member of dialout. I am!!!
But interesting is the output of a dmesg - command:
usb 1-4.2: Manufacturer: FTDI [3303686.111831] usb 1-4.2: SerialNumber: A50285BI [3303686.117000] ftdi_sio 1-4.2:1.0: FTDI USB Serial Device converter detected [3303686.117095] usb 1-4.2: Detected FT232RL [3303686.117884] usb 1-4.2: FTDI USB Serial Device converter now attached to ttyUSB0 [3303866.054206] usb 1-4.2: USB disconnect, device number 34 [3303866.055121] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0 [3303866.055228] ftdi_sio 1-4.2:1.0: device disconnected [3307353.465583] usb 1-4.2: new full-speed USB device number 35 using xhci_hcd [3307353.561536] usb 1-4.2: New USB device found, idVendor=0403, idProduct=6001 [3307353.561545] usb 1-4.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [3307353.561550] usb 1-4.2: Product: FT232R USB UART [3307353.561554] usb 1-4.2: Manufacturer: FTDI [3307353.561558] usb 1-4.2: SerialNumber: A50285BI [3307353.566091] ftdi_sio 1-4.2:1.0: FTDI USB Serial Device converter detected [3307353.566201] usb 1-4.2: Detected FT232RL [3307353.567064] usb 1-4.2: FTDI USB Serial Device converter now attached to ttyUSB0
Just these last few lines of the output show clearly, that the programmer is constantly being attached and then again disconnectet from the serial port. The programmer is a FT232RL FTDI USB to TTT Serial Adapter Module with 3.3 and 5 V.
Can anybody help me with this weird thing?