Single name in /dev for Arduino Leonardo needed

When I connect an Arduino UNO (ATmega328p) via USB I get /dev/ttyUSB0 or /dev/ttyUSB1. With the Leonardo (ATmega32U4), it's /dev/ttyACM0 or /dev/ttyACM1.

The names alternate, which is annoying since I have to open the Tools menu and change a setting each time I unplug to test and replug to make changes.

Is there a way to force a single name? I tried a udev rule with SYMLINK+=ttyUSB_LEO, but it did not work.

SUBSYSTEMS=="usb", ATTRS{idVendor}=="2341", ATTRS{idProduct}=="8036", MODE:="0666", SYMLINK+=ttyUSB_LEO
KERNEL=="ttyACM*", ATTRS{idVendor}=="2341", ATTRS{idProduct}=="8036", MODE:="0666"

udev is certainly the right way to create a persistent name.

Did you try putting the symbolic link name in quotes?

What do you see when running udevadm monitor, then replugging the Arduino?

~$ udevadm monitor
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[7760.688539] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4 (usb)
KERNEL[7760.688708] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.0 (usb)
KERNEL[7760.689178] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.0/tty/ttyACM0 (tty)
KERNEL[7760.689336] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.1 (usb)
UDEV  [7760.694272] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4 (usb)
UDEV  [7760.696934] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.0 (usb)
UDEV  [7760.697580] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.1 (usb)
UDEV  [7760.700994] add      /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.0/tty/ttyACM0 (tty)

Revised Rule:

ATTRS{idVendor}=="2341", ATTRS{idProduct}=="8036", ENV{ID_MM_DEVICE_IGNORE}="1"
ATTRS{idVendor}=="2341", ATTRS{idProduct}=="8036", ENV{MTP_NO_PROBE}="1"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="2341", ATTRS{idProduct}=="8036", MODE:="0666"
KERNEL=="ttyACM*", ATTRS{idVendor}=="2341", ATTRS{idProduct}=="8036", MODE:="0666", SYMLINK+="ttyUSB_LEO"

I now see /dev/ttyUSB_LEO, but it is not offered as an alternative port by the Arduino IDE.
The first time I plugged in the Leonardo I got the above 8 lines, followed a few seconds later by another set with 'add' replaced by 'deleted', and another 'add' set. All with the same data. Other times I just get a single 'add' set.

Well, it looks like the IDE only cares for true device files. Rather than adding a symlink, then, try renaming the device file, either with a script or perhaps udev includes renaming as a built-in action?

Or find out how the IDE decides which devices to present.

I don’t know what the add/delete/add cycle means, but I guess it’s not really important.

Moved: This thread is more suitable in <Linux - Embedded & Single-board computer> and has been moved accordingly to help your thread/question get the exposure it deserves.