在弄清楚udev规则结束后(可以参考我之前的博文)，我们来看看。rikirobot设备管理。
rikirobot你可以去源码github.com搜索下载，很多热心的网友已经打包上传了，包括我们下面要讨论的。setup例如，文件，
https://github.com/ykevin/rikirobot_setup
项目使用usb接口（包括USB串口)通信时，我们都希望有一个固定的设备名称供程序调用。usb即插即用设备，udev又是动态随机命名，所以，很难保证每次设备的名称都不变；因此，我们需要编写一些名称映射规则文件，对usb设置设备。
规则文件以.rules规则配置路径一般为：
/etc/udev/rules.d/*由于这些文件具有优先级，一般在名称前添加一个数字，系统在加载时会根据数字进行排序，在数字较小的前排（优先级相对较高）。
规则格式示例： KERNEL=="ttyUSB*", ATTRS{idVendor}=="xxxx", ATTRS{idProduct}=="xxxx", MODE:="0777", SYMLINK ="device_name" 其中 ATTRS{idVendor}=="xxxx" ATTRS{idProduct}=="xxxx"
从查询到的结果里进行配置。
下面我自己通过。ch340控制ROS以汽车通讯的实际配置为例。
查询命令
$ ls -l /dev |grep USB crw-rw---- 1 root dialout 188, 0 Jan 10 04:56 ttyUSB0 $ ls -l /dev |grep serial drwxr-xr-x 4 root root 80 Jan 10 04:56 serial
我们可以找到串口设备；
$ lsusb Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter Bus 001 Device 003: ID 248a:8367 Maxxter USB2.0 Hub Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
再仔细看，
$lsusb -v
一切都可以找到usb设备的详细信息包括要找到的ch340，内容如下
Bus 001 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter Couldn't open device, some information will be missing Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 255 Vendor Specific Class bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x1a86 QinHeng Electronics idProduct 0x7523 HL-340 USB-Serial adapter bcdDevice 2.64 iManufacturer 0 iProduct 2 iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 0x0027 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 98mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 3 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 1 bInterfaceProtocol 2 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 1 熟悉usb朋友可以一下子看到这个usb通信协议是bulk，其中endpoint为0x8?为IN，0x0?的为Ｏut，例如，用户的通讯是EP2-0x82(IN)/0x02(out)，还有一个中断传输端口EP1-0x81(IN)。具体想了解usb这里可以看看规范，
USB 2.0 Specification | USB-IF
设备的idVendor和idProduct分别为，
idVendor 0x1a86 QinHeng Electronics idProduct 0x7523 HL-340 USB-Serial adapter
我们可以建立文件名称的规则 /etc/udev/rules.d/58-riki.rules
与ch340对应的规则是内容 KERNEL=="ttyUSB?", SUBSYSTEM=="tty", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="7523", MODE="0777" SYMLINK ="rikibase"
规则文件配置完成后，执行命令 service udev reload service udev restart 然后你就可以在//dev找到我们想看的东西rikibase(如果没有，重启)， ls /dev/rikibase
然后在ros相应的launch在文件中，可以固定配置的参数 /dev/rikibase了。ros的launch文件 serial_port参数定义为/dev/rikibase可实现相应硬件的调用设置，不必插拔usb后在查看到底是那个端口号反复修改launch文件。
全部开源riki底盘树莓派中系统使用的规则配置示例及说明：
58-riki.rules
KERNEL=="ttyACM?", SUBSYSTEM=="tty", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="0483", MODE="0777" SYMLINK+="rikibase"
KERNEL=="ttyACM?", SUBSYSTEM=="tty", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="5740", MODE="0777" SYMLINK+="rikiarm_left"
KERNEL=="ttyACM?", SUBSYSTEM=="tty", ATTRS{idVendor}=="2341", ATTRS{idProduct}=="0046", MODE="0777" SYMLINK+="rikiarm_right"
KERNEL=="ttyUSB?", SUBSYSTEM=="tty", ATTRS{idVendor}=="10c4", ATTRS{idProduct}=="ea60", ATTRS{serial}=="0001", MODE="0777" SYMLINK+="rikilidar"
KERNEL=="ttyUSB?", SUBSYSTEM=="tty", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="7523", MODE="0777" SYMLINK+="rikibase"
KERNEL=="ttyUSB?", SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", MODE="0777" SYMLINK+="rikibase"
KERNEL=="ttyUSB?", SUBSYSTEM=="tty", ATTRS{idVendor}=="067b", ATTRS{idProduct}=="2303", MODE="0777" SYMLINK+="rikilidar"558-orbbec-usb.rules
# Make primesense device mount with writing permissions (default is read only for unknown devices)
SUBSYSTEM=="usb", ATTR{idProduct}=="0401", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0402", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0403", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0404", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0405", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0406", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0407", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0408", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="0409", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"
SUBSYSTEM=="usb", ATTR{idProduct}=="040a", ATTR{idVendor}=="2bc5", MODE:="0666", OWNER:="ubuntu", GROUP:="video"49-teensy.rules
ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="04[789B]?", ENV{ID_MM_DEVICE_IGNORE}="1"
ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="04[789A]?", ENV{MTP_NO_PROBE}="1"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="04[789ABCD]?", MODE:="0666"
KERNEL=="ttyACM*", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="04[789B]?", MODE:="0666"10-local-rpi.rules
SUBSYSTEM=="vchiq", GROUP="video", MODE="0660"解释：
VCHIQ is a command interface between the running Linux kernel and peripherals (among other things) in the VideoCore silicon. /dev/vchiq provides generic userspace access to those commands for use by (at minimum) the camera and audio subsystems as well. It's a decently dangerous interface to expose to random programs, hence the somewhat restrictive permissions by default.
40-scratch.rules
ATTRS{idVendor}=="0694", ATTRS{idProduct}=="0003", SUBSYSTEMS=="usb", ACTION=="add", MODE="0666", GROUP="plugdev"
99-com.rules
SUBSYSTEM=="input", GROUP="input", MODE="0660"
SUBSYSTEM=="i2c-dev", GROUP="i2c", MODE="0660"
SUBSYSTEM=="spidev", GROUP="spi", MODE="0660"
SUBSYSTEM=="bcm2835-gpiomem", GROUP="gpio", MODE="0660"
SUBSYSTEM=="gpio*", PROGRAM="/bin/sh -c '\
chown -R root:gpio /sys/class/gpio && chmod -R 770 /sys/class/gpio;\
chown -R root:gpio /sys/devices/virtual/gpio && chmod -R 770 /sys/devices/virtual/gpio;\
chown -R root:gpio /sys$devpath && chmod -R 770 /sys$devpath\
'"
KERNEL=="ttyAMA[01]", PROGRAM="/bin/sh -c '\
ALIASES=/proc/device-tree/aliases; \
if cmp -s $ALIASES/uart0 $ALIASES/serial0; then \
echo 0;\
elif cmp -s $ALIASES/uart0 $ALIASES/serial1; then \
echo 1; \
else \
exit 1; \
fi\
'", SYMLINK+="serial%c"本文结束