PLEBBLE - node setup
Instructions

1. (optional,advanced) Make sure you have UPnP function enabled in your broadband router.
    The node will try to program the router to forward ports 16671,16672,16673,15580 to itsels, so other nodes
    can initate connections with your node. If this process fails your node will still be working fine, but
    without helping inter-node connectivity (other nodes will try to reah you without success) which reduces
    global performance. 
    If you skip this step there is a chance the node will success opening ports, but if you feel skilled it is
    worth to access the router configuration and make sure UPnP function is enabled. Alternatively to UPnP you
    can program manually port forwarding. Range of TCP ports 16670-16680 should map to same range in the node.
    Program DHCP to assign the same IP address to the node's MAC address, to make sure port forwarding manual
    configuration lasts.
    Your router can tipically be accessed via the following URLs accessible via your internet browser:
        http://192.168.0.1 or http://192.168.1.1 
    But it could be any other, depending on your local LAN configuration, if none of these works:
    Example, type in the terminal: 
    $> netstat -rn
    Kernel IP routing table
    Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
    0.0.0.0         192.168.0.1     0.0.0.0         UG        0 0          0 enp0s25
    192.168.0.0     0.0.0.0         255.255.255.0   U         0 0          0 enp0s25
    
    The use the ip address in your internet browser to access your router.
    Example: http://192.168.0.1
    Search in advanced configuration for UPnP and make sure it is enabled.
    Make also sure the firewall, if enabled, doesn't filter packets in the port range 16670-16680.

2. Download and record the US Operating System for the Raspberry Pi. 
	  The image file can be found at:
      http://plebble.io/downloads/raspberry_pi/plebble-os_raspi_alpha-11_b4b8240eb38bcc7ea270f4c6a1d9f248adeb3567.zip
      Check the size of the file after downloading it. It should be exactly 545362659 bytes.
      Check the integrity of the downloading file calculating its sha256 checksum:
      S> sha256sum plebble-os_raspi_alpha-11_b4b8240eb38bcc7ea270f4c6a1d9f248adeb3567.zip 
         d9748ffdc7c57a55e6cd78d4c2ec57c7c2ba894358f90dc9dce3eb3ca7a86736
    2.1  Uncompress & record the US Operating System into the microSD card.
         After insrting the sdCard in the microSD reader slot type in the command line terminal
         $> dmesg
            Analyze the last lines in search of the device file the card has been assigned to.
            e.g. /dev/sdc (it could be /dev/sdd or /dev/mmc...)
            Install zstd file compressor. In debian and ubuntu linux systems type:
         $> unzip plebble-os_raspi_alpha-11_b4b8240eb38bcc7ea270f4c6a1d9f248adeb3567.zip
            dd of=/dev/... if=...image_file
            wait until the process finishes, eject the device:
         $> eject /dev/...
3. Insert the recorded microSD card in the raspberry pi slot.
	Tested models: Raspberry PI 3B+ with at least 16Gb microSD
    3.1. Connect the raspberry pi to your broadband router using a (short) ethernet cable.
    3.2. Connect a TV using a HDMI cable.
    3.3. Connect a USB keyboard.
    3.4. Power up the raspberry pi using an official power supply.
    3.5. Wait approximately 15 minutes until the instalation finishes
    3.6. Login with the user and password shown in screen. You’ll be forced to change the password. 
          Recommended procedure:
       3.6.1. Write down on paper a long sequence (~10) of random numbers and letters.
       3.6.1. Enter the new password twice.
       3.6.3. Store the paper in a safe place.
    3.7. Write down your IP address for later ssh access.
      Know your LAN IP address. Example:
      $> hostname -I
      192.168.0.26 ...
    3.8. Type “us-help” to know more about the programs wallet and gov.
    3.9. Type exit to terminate the session.
    3.10. Unplug the HDMI cable and the keyboard
    3.11. Leave the node running 24/7 beside the broadband router.
4. Access your node via ssh (port 16671)
    Example:
    $> ssh -p16671 192.168.0.26
5. (optional) Check installation.
    Go to to the following URL using a computer or the mobile using the WIFI of the router.
    http://adsl4ever.com/ip
    annotate your public IP address 
    send your public IP address by email to other.arkitech@protonmail.com 
    you'll receive a response with an assessment of a successful installation, or any issue detected.