我正在Android设备上运行Linux chroot环境，并试图与基于Atmel atmega2560（Arduino Mega衍生）微控制器进行通信。 执行“ls -ld / dev / ttyACM0”会显示调制解调器的以下权限：
crw------- 1 root root 166, 0 Feb 11 22:28 /dev/ttyACM0 “lsusb”告诉我：
Bus 003 Devices: ID 03eb:204b Atmel Corp. LUFA USB to Serial Adpater Project
“udevadm info –attribute-walk –name = ttyACM0”说：
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/platform/sunxi_hcd_host0/usb3/3-1/3-1:1.0/tty/ttyACM0': KERNEL=="ttyACM0" SUBSYSTEM=="tty" DRIVER=="" looking at parent device '/devices/platform/sunxi_hcd_host0/usb3/3-1/3-1:1.0': KERNELS=="3-1:1.0" 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/platform/sunxi_hcd_host0/usb3/3-1': KERNELS=="3-1" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{bDeviceSubClass}=="00" ATTRS{bDeviceProtocol}=="00" ATTRS{devpath}=="1" ATTRS{idVendor}=="03eb" ATTRS{speed}=="12" ATTRS{bNumInterfaces}==" 2" ATTRS{bConfigurationValue}=="1" ATTRS{bMaxPacketSize0}=="8" ATTRS{busnum}=="3" ATTRS{devnum}=="20" ATTRS{configuration}=="" ATTRS{bMaxPower}=="200mA" ATTRS{authorized}=="1" ATTRS{bmAttributes}=="c0" ATTRS{bNumConfigurations}=="1" ATTRS{maxchild}=="0" ATTRS{bcdDevice}=="8888" ATTRS{avoid_reset_quirk}=="0" ATTRS{quirks}=="0x0" ATTRS{serial}=="55330343534351415012" ATTRS{version}==" 1.10" ATTRS{urbnum}=="12" ATTRS{manufacturer}=="RRD (www.ru" ATTRS{removable}=="unknown" ATTRS{idProduct}=="204b" ATTRS{bDeviceClass}=="02" ATTRS{product}=="RUMBA - ATmega 2560 co" looking at parent device '/devices/platform/sunxi_hcd_host0/usb3': KERNELS=="usb3" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{bDeviceSubClass}=="00" ATTRS{bDeviceProtocol}=="00" ATTRS{devpath}=="0" ATTRS{idVendor}=="1d6b" ATTRS{speed}=="12" ATTRS{bNumInterfaces}==" 1" ATTRS{bConfigurationValue}=="1" ATTRS{bMaxPacketSize0}=="64" ATTRS{authorized_default}=="1" ATTRS{busnum}=="3" ATTRS{devnum}=="1" ATTRS{configuration}=="" ATTRS{bMaxPower}==" 0mA" ATTRS{authorized}=="1" ATTRS{bmAttributes}=="e0" ATTRS{bNumConfigurations}=="1" ATTRS{maxchild}=="1" ATTRS{bcdDevice}=="0304" ATTRS{avoid_reset_quirk}=="0" ATTRS{quirks}=="0x0" ATTRS{serial}=="sunxi_hcd_host0" ATTRS{version}==" 1.10" ATTRS{urbnum}=="777" ATTRS{manufacturer}=="Linux 3.4.39 sunxi_hcd-hcd" ATTRS{removable}=="unknown" ATTRS{idProduct}=="0001" ATTRS{bDeviceClass}=="09" ATTRS{product}=="sunxi_hcd host driver" looking at parent device '/devices/platform/sunxi_hcd_host0': KERNELS=="sunxi_hcd_host0" SUBSYSTEMS=="platform" DRIVERS=="sunxi_hcd_host0" looking at parent device '/devices/platform': KERNELS=="platform" SUBSYSTEMS=="" DRIVERS==""
因此，我创build了包含以下内容的文件“/etc/udev/rules.d/99-arduino.rules”：
SUBSYSTEMS=="usb", ATTRS{idVendor}=="03eb", ATTRS{idProduct}=="204b", MODE:="0666"
试图允许我的用户读/写权限。 我不能用root权限来运行我的应用程序，我需要ttyACM *的所有权（注意我也尝试了OWNER =“myusername”而不是MODE：=“0666”）。
事实证明，我只需要做“服务udev重启”，并突然开始工作。 以前我尝试过“udevadm control –reload-rules”，“udevadm control –reload”，“udevadm control trigger”，然后重新启动系统，但都没有工作。