Network configuration

Ruff provides three ways to configure a network:

  • Broadcasting mode - the developement board is not required to connect to the PC in this mode.
  • LAN mode - the development board must be connected to the same network where the PC is connected to. Alson, AP mode can be initiated on the development board to set up a temporary wireless network.
  • USB serial mode - to use this mode, a USB-to-serial driver ([Windows][usb-serial-windows], [OS X][usb-serial-osx]) must be installed in the PC, and the development board needs to connect to the PC by a USB data cable.

The First Configuration

The Ruff development board will boot up into Ruff OS after a connection between the micro USB on the board and a USB power cable.

  • You will soon see a red LED flashing that indicates the board is waiting for network configuration after system startup.

Broadcasting Mode

  1. Now we can execute the command rap wifi to configure WiFi settings:
rap wifi
  1. Please enter your SSID and password. If the PC is connected to multiple networks, rap will ask for an IP address to broadcast from. ALso, the development board will indicate network connection status via the onboard LED:
  • Blue LED flashing - the board has received the settings and is trying to connect.
  • Blue LED steady - a successful connection to the network.
  • Blue LED flashing followed by red LED flashing - the board is failed to connect to the network or timed out. Please retry.

The development board and PC need to be in the same network. Currently Ruff supports only 2.4GHz band, so please configure a hotspot with 2.4G. For some dual-band routers, 2.4G and 5G bands share the same network. If so, your computer can still connect to a 5G hotspot.


  • What if the red LED onboard keeps flashing, and indicates no network settings received?
    • The wireless router might place restrictions on network broadcasting. For example, some might prevent two or more wireless devices from connecting.
    • The network might be in poor condition. Please try again, or address the condition of the wireless network.
  • What if the command rap wifi shows the device has been already connected, but the development board is still waiting for settings or trying to connect?
    • It is possible that multiple Ruff devices on one network are waiting for network configuration. You may see the status of other Ruff devices that have connected to the network and sent back signal successfuly to the PC.

AP Mode (A Special Case of LAN Mode)

Please follow steps shown below to initiate the AP Model:

  1. Press the FUNC button onboard. The flashing frequency of red LED will increase, indicating that the development board has entered AP mode.
  2. Connect to the hotspot that the Ruff development board has setup(SSID Ruff_[SN], or Ruff_[MAC] for some old devices).
  3. Execute the command rap wifi --lan ap to configure WiFi settings for the development board.
rap wifi --lan ap

USB Serial Mode

PLease follow steps shown below to initiate USB Serial mode:

  1. Install a USB-to-serial driver on your PC (Windows, OSX).
  2. Connect the development board with the PC by a USB data cable. Please confirm it is recognized as a serial device in one of the following ways:
  • For Windows - open the device manager and confirm that “Ports (COM & LPT)” > “Prolific USB-to-Serial Comm Port (COMx)” exists.
  • For OS X - execute the command ls /dev/tty.usbserial* to list related serial devices:
ls /dev/tty.usbserial*
  1. Execute the command rap wifi --serial to configure WiFi settings for the development board. If multiple USB serial devices are available, rap will ask you to select one of the devicesx.
rap wifi --serial


  • What if the output shows that it cannot open the serial port during network configuration?
    • It is posiible that other programs (like plink or screen) occupy the serial device. Please close related programs and try again. In this situation, users of OS X might need to disconnect and then reconnect the device physically.

Changing Configuration

Ruff does not support to change network configuration via broadcasting. If you would like to change, you need to use one of the other two modes or to reset the development board.

LAN Mode

LAN mode requires that the development board and the PC be connected to the same network, and you need the network’s IP address to proceed. For example:

rap wifi --lan

USB Serial Mode

The procedure for changing configuration in USB serial mode is the same as in the steps outlined above in The First Configuration.

Resetting Wifi

Please press and hold the RESET button for 3 ~ 10 seconds to reset the WiFi configuraton,.

Resetting Development Board

Please press and hold the RESET button for 10 seconds to reset the development board. The development board will be reset, and you can configure network settings via the same process in The First Configuration.