Software » CANHub

h1. CANHub

h2. Intro

CANServer is an Server-Client library that provides multiple applications access to an CAN-Bus via TCP/IP.

Every message received via CAN gets send to all clients. When an client sends an message, it is send 

via CAN-Bus and also to the other clients.

The physical CAN-Bus is optional.

h3. Usecases

* CAN over ethernet

* Graphical user interface for home automatisation

  An laptop/tablet can be connected to an server via WLAN

* Recording/Replay

  An PC-Application could record CAN messages and replay them.

* Debugging

  Show CAN traffic while interacting with the bus with other devices.

* WLAN CAN-Bridge

  Two CAN segments can be connected via WLAN

h3. Architecture

<pre>

        Server                      TCP       Client

        List

        {                             /-----> connectionTcpClient

            connectionCan             |

            connectionTcpServer       |

            connectionTcpServer <-----/

            connectionTcpServer

        }

</pre>

<pre>

      class CConnector {

         signal dataIn(SMsg);

         slot dataOut(SMsg);

      }

</pre>

<pre>

        Server                      

        List

        {

            connectionCan       <-----\

      /---- connectionTcpServer <-----|

      |     connectionTcpServer <-----|

      |     connectionTcpServer <-----|

      | }                             |

      |                               |

      \--> serverDataInSlot-----------/

</pre>

Each connection has an id which is an ongoing number handled by the server.

## Terminal Output

The server prints a dynamic list with the connections and traffic statistics.

- ID/Type

- Connection uptime

* in/out messag count

* in msg/s

Example:

<pre>

Id Target        Uptime   In   Out   In/s

-----------------------------------------

0: CAN           0:10s    12   55    0

1: Server        0:10s    3    51    0

2: Client        0:05s    43   52    0

3: Client        0:01s    1    57    0

</pre>

h2. Loop detection

Two servers can be connected (e.g. for connecting multiple CAN-segments). But for each connection there must 

only be a single connection line with a pair of connectors. Otherwise messages would bounce forever.

Such loops should be detected:

The TCP-Server generates an periodical Heartbeat which is send/routed to every tcp connection.

When server sends heartbeat, it must not receive it back. Otherwise there is a loop. How to generate uuid?

<pre>

        Server                      TCP       Server

        List                                  List

        {                                     {

            connectionCan                           connectionCan

            connectionTcpServer        /----------> connectionTcpClient

            connectionTcpServer <-----/      /----> connectionTcpServer     <----Doubled connection

            connectionTcpClinet <-----------/

        }                                     }

</pre>

h2. Ansi

box(x1,y1,x2,y2)

hLine(x1,y1,x2)

vLine(x1,y1,y2)

<pre>

┬

│

┴

├──┤

┌─┐

│ │

└─┘

</pre>

   QLoggingCategory::setFilterRules("*.debug=false");

   qSetMessagePattern("[%{time process}] %{function}: %{message}");

   qDebug("Happy debugging");

h1. Links

https://www.sciencebuddies.org/science-fair-projects/references/ascii-table