improve documentation for Ubuntu

README.md

@@ -17,7 +17,7 @@ For more info see our [wiki](http://wiki.bitcraze.se/ "Bitcraze Wiki").
 
 * [Uninstall the cflib if you don't want it any more](http://pip-python3.readthedocs.org/en/latest/reference/pip_uninstall.html), `pip uninstall cflib`
 
-Note: If you are developing for the [cfclient][cfclient] you must use python3.
+Note: If you are developing for the [cfclient][cfclient] you must use python3. On Ubuntu (16.04, 18.08) use `pip3` instead of `pip`.
 
 ### Linux, OSX, Windows
 
@@ -76,13 +76,18 @@ The following steps make it possible to use the USB Radio without being root.
 
 ```
 sudo groupadd plugdev
-sudo usermod -a -G plugdev <username>
+sudo usermod -a -G plugdev $USER
 ```
 
+You will need to log out and log in again in order to be a member of the plugdev group.
+
 Create a file named ```/etc/udev/rules.d/99-crazyradio.rules``` and add the
 following:
 ```
+# Crazyradio (normal operation)
 SUBSYSTEM=="usb", ATTRS{idVendor}=="1915", ATTRS{idProduct}=="7777", MODE="0664", GROUP="plugdev"
+# Bootloader
+SUBSYSTEM=="usb", ATTRS{idVendor}=="1915", ATTRS{idProduct}=="0101", MODE="0664", GROUP="plugdev"
 ```
 
 To connect Crazyflie 2.0 via usb, create a file name ```/etc/udev/rules.d/99-crazyflie.rules``` and add the following:
@@ -90,6 +95,12 @@ To connect Crazyflie 2.0 via usb, create a file name ```/etc/udev/rules.d/99-cra
 SUBSYSTEM=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="5740", MODE="0664", GROUP="plugdev"
 ```
 
+You can reload the udev-rules using the following:
+```
+sudo udevadm control --reload-rules
+sudo udevadm trigger
+```
+
 [cfclient]: https://www.github.com/bitcraze/crazyflie-clients-python