How to bind arduino as a fix block-device --- /dev/ttyACM0?

Question

I want to bind my Arduino Mega as /dev/ttyACM0. Sometimes, it turns out to be /dev/ttyACM0 and sometimes as /dev/ttyACM1.

I have taken help from this question and this tutorial

Someone please help me to achieve that as there are only 2 entries in /etc/udev/rules.d :-

20-crystalhd.rules
98-kexec.rules

The output of udevadm info -a -p $(udevadm info -q path -n /dev/ttyACM0) :-

Udevadm info starts with the device specified by the devpath and then walks up the chain of parent devices. It prints for every device found, all possible attributes in the udev rules key format. A rule to match, can be composed by the attributes of the device and the attributes from one single parent device.

looking at device '/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5/2-1.5:1.0/tty/ttyACM0':
KERNEL=="ttyACM0"
SUBSYSTEM=="tty"
DRIVER==""

looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5/2-1.5:1.0':
KERNELS=="2-1.5:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="cdc_acm"
ATTRS{bInterfaceClass}=="02"
ATTRS{bmCapabilities}=="6"
ATTRS{bInterfaceSubClass}=="02"
ATTRS{bInterfaceProtocol}=="01"
ATTRS{bNumEndpoints}=="01"
ATTRS{supports_autosuspend}=="1"
ATTRS{bAlternateSetting}==" 0"
ATTRS{bInterfaceNumber}=="00"

looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5':
KERNELS=="2-1.5"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{devpath}=="1.5"
ATTRS{idVendor}=="2341"
ATTRS{speed}=="12"
ATTRS{bNumInterfaces}==" 2"
ATTRS{bConfigurationValue}=="1"
ATTRS{bMaxPacketSize0}=="8"
ATTRS{busnum}=="2"
ATTRS{devnum}=="4"
ATTRS{configuration}==""
ATTRS{bMaxPower}=="100mA"
ATTRS{authorized}=="1"
ATTRS{bmAttributes}=="c0"
ATTRS{bNumConfigurations}=="1"
ATTRS{maxchild}=="0"
ATTRS{bcdDevice}=="0001"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{quirks}=="0x0"
ATTRS{serial}=="55431313937351C05151"
ATTRS{version}==" 1.10"
ATTRS{urbnum}=="17"
ATTRS{ltm_capable}=="no"
ATTRS{manufacturer}=="Arduino (www.arduino.cc)"
ATTRS{removable}=="removable"
ATTRS{idProduct}=="0042"
ATTRS{bDeviceClass}=="02"

looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-1':
KERNELS=="2-1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="01"
ATTRS{devpath}=="1"
ATTRS{idVendor}=="8087"
ATTRS{speed}=="480"
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{busnum}=="2"
ATTRS{devnum}=="2"
ATTRS{configuration}==""
ATTRS{bMaxPower}=="0mA"
ATTRS{authorized}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bNumConfigurations}=="1"
ATTRS{maxchild}=="6"
ATTRS{bcdDevice}=="0000"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{quirks}=="0x0"
ATTRS{version}==" 2.00"
ATTRS{urbnum}=="70"
ATTRS{ltm_capable}=="no"
ATTRS{removable}=="unknown"
ATTRS{idProduct}=="0024"
ATTRS{bDeviceClass}=="09"

looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2':
KERNELS=="usb2"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{devpath}=="0"
ATTRS{idVendor}=="1d6b"
ATTRS{speed}=="480"
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{authorized_default}=="1"
ATTRS{busnum}=="2"
ATTRS{devnum}=="1"
ATTRS{configuration}==""
ATTRS{bMaxPower}=="0mA"
ATTRS{authorized}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bNumConfigurations}=="1"
ATTRS{maxchild}=="2"
ATTRS{bcdDevice}=="0310"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{quirks}=="0x0"
ATTRS{serial}=="0000:00:1d.0"
ATTRS{version}==" 2.00"
ATTRS{urbnum}=="42"
ATTRS{ltm_capable}=="no"
ATTRS{manufacturer}=="Linux 3.10.0-123.13.2.el7.x86_64 ehci_hcd"
ATTRS{removable}=="unknown"
ATTRS{idProduct}=="0002"
ATTRS{bDeviceClass}=="09"
ATTRS{product}=="EHCI Host Controller"

looking at parent device '/devices/pci0000:00/0000:00:1d.0':
KERNELS=="0000:00:1d.0"
SUBSYSTEMS=="pci"
DRIVERS=="ehci-pci"
ATTRS{irq}=="23"
ATTRS{subsystem_vendor}=="0x104d"
ATTRS{broken_parity_status}=="0"
ATTRS{class}=="0x0c0320"
ATTRS{companion}==""
ATTRS{enabled}=="1"
ATTRS{consistent_dma_mask_bits}=="32"
ATTRS{dma_mask_bits}=="32"
ATTRS{local_cpus}=="000f"
ATTRS{device}=="0x1c26"
ATTRS{uframe_periodic_max}=="100"
ATTRS{msi_bus}==""
ATTRS{local_cpulist}=="0-3"
ATTRS{vendor}=="0x8086"
ATTRS{subsystem_device}=="0x9081"
ATTRS{numa_node}=="-1"
ATTRS{d3cold_allowed}=="1"

looking at parent device '/devices/pci0000:00':
KERNELS=="pci0000:00"
SUBSYSTEMS==""
DRIVERS==""

Where should I edit my entries in which files and how. Please explain in somewhat depth as I am much naive!! Please help me establish this. It's already taking my mind and mood off.

Note that on modern versions of udev, the /etc/udev/rules.d is only for rules customized for that specific system (either by sysadmin or by other rules or some other automation). The majority of udev rules can be found at [/usr]/lib/udev/rules.d instead (whether or not there is /usr at the beginning of the path depends on distribution). — telcoM, Jan 20 '21 at 21:53

score 0 · Answer 1 · edited Apr 16 '19 at 14:38

I'm not in front of a linux system right now, but I would start by tracking down what writes /etc/udev/rules.d/70-persistent-net.rules and use that as a template.

Specifically, every time a wifi device is plugged in, the interface name, such as wlan0, wlan1, etc. becomes fixed based on some device attribute (I presume MAC address).

You can follow the same convention to create your own udev rules for the Arduino device.

How to bind arduino as a fix block-device --- /dev/ttyACM0?

1 Answers1