PPMonitor dataflow diagram

/*

PPMonitor dataflow diagram, showing how data gets from the various sensors to
the users PC screen.

Licenced as Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) -- http://creativecommons.org/licenses/by-sa/3.0/

v1.00 : 05APR2011
    Initial internal release.

v1.01 : 05APR2011
    ROJ - Group sensors into cluster & group servers/clients into cluster. Also added "TCP/IP" link to SQL Database.
    JBJ - Split "Top Board" into components.

v1.02 : 05APR2011
    Pubic Release.
    ROJ - Add distinct "Serial Sensor" path.
    ROJ - Add more clusters, they rock.
    ROJ - Tweak colours.
    ROJ - Add alternative path for SHT7x sensor.
    ROJ - Change CAN path to "dotted" to indicate old tech.
    TH  - Spelling correction to "PPMonitor Unit".

v1.03 : 07APR2011
    ROJ - Corrected spelling on "Formaldemeter" node label.
    ROJ - Added optional settings to scale down to A4 sized image.
    ROJ - Added version & date label to image.

*/
digraph SensorToScreen {
    /* We really like Arial! */
    fontname = "Arial"; node [ fontname = "Arial" ]; edge [ fontname = "Arial" ];

    /* Brand the output with the following info... */
    label = "http://ppm-technology.com .:. PPMonitor DataFlow Diagram .:. v1.03 .:. 07APR2011\nhttp://creativecommons.org/licenses/by-sa/3.0/";

    /* Use these for PDF o/p to A4
     *
     * Comment them out for anything else to get the best resolution. */
    size = "8.3,11.7";
    ratio = fill;
    /******************************************************************/


    /* The PPMoniotr Node */
    subgraph cluster_A {

        /* Example Serial Sensor */
        subgraph cluster_0s {
            node [ style = filled ];

            as0;

            label = "Serial Sensor Assembly";
            color = "blue";
            fontcolor = "blue";
        }

        /* Example Voltage Sensor */
        subgraph cluster_VoltageSensor {
            node [ style = filled ];

            av0 -> av1;

            label = "Voltage Sensor Assembly";
            color = "blue";
            fontcolor = "blue";
        }

        /* Example Current Sensor */
        subgraph cluster_0c {
            node [ style = filled ];

            ac0 -> ac1;

            label = "Current Sensor Assembly";
            color = "blue";
            fontcolor = "blue";
        }

        /*  ADC type Top-Board */
        subgraph cluster_TopBoard_ADC {
            node [ style = filled ];

            ADC -> ZERO -> LPF -> vIEEE754 -> SPAN -> Baseline;

            label = "Top Board (SPIADC Code)";
            color = "blue";
            fontcolor = "blue";
        }

        /* USART type Top-Board */
        subgraph cluster_TopBoard_USART {
            node [ style = filled ];

            Offset -> sIEEE754;

            label = "Top Board (SPIUSART Code)";
            color = "blue";
            fontcolor = "blue";
        }

        /* Main-Board */
        subgraph cluster_MainBoard {
            node [ style = filled ];

            PIC -> Relays;
            PIC -> ETRX2                [ label = "SPI", dir = both ];
            PIC -> CANBus               [ dir = both, style = dotted ];
            SHT75 -> FGMD -> PIC        [ label = "Serial" ];
            SHT75 -> PIC                [ label = "I2C", style = dashed ];

            label = "Main Board";
            color = "blue";
            fontcolor = "blue";
        }

        labelloc = b;
        label = "PPMonitor Unit";
        color = "forestgreen";
        fontcolor = "forestgreen";
        style = rounded;
    }

    subgraph cluster_B {

        subgraph cluster_2 {
            node [style=filled];

            ETRX2USB -> ZigBeeService   [ dir = both ];
            CANCntrl-> PPMService       [ dir = both, style = dotted ];
            PPMService -> ZigBeeService

            label = "PC (Server Side)";
            color=blue;
            fontcolor = blue;
        }

        subgraph cluster_3 {
            node [style=filled];

            Screen -> Client [ dir = both ];

            label = "PC (Client Side)";
            color=blue;
            fontcolor = blue;
        }

        SQLDB;

        color=red;
        fontcolor = red;
        labelloc = b;
        label = "Users PC";
        style = rounded;
    }

    /*
     * Inter-Cluster connections.
     *
     *************************************************************************/
    /* Sensors to Top-Board */
    as0 -> Offset                       [ label = "Serial" ];
    ac1 -> ADC                          [ label = "4-20mA" ];
    av1 -> ADC                          [ label = "0 - 5V" ];

    /*  Top-Board to Main-Board */
    Baseline -> PIC                      [ label = "SPI" ];
    sIEEE754 -> PIC                      [ label = "SPI" ];

    /*  Main-Board to PC */
    ETRX2 -> ZigBeeNet -> ETRX2USB      [ label = "SCAST", dir = both ];
    CANBus -> CANCntrl                  [ label = "CAN Bus", dir = both, style = dotted ];

    /* Clients & Servers */
    ZigBeeService -> SQLDB              [ dir = both ];
    PPMService -> SQLDB                 [ dir = both ];
    SQLDB -> Client                     [ dir = both ];
    Client -> PPMService                [ dir = both ];
    SQLDB -> Other                      [ dir = both, label = "TCP/IP Connection" ];

    /*
     * Node setup
     *
     *************************************************************************/
    /* Sensors and TXBoards. */
    av0                                 [ label = "Sensor\n(e.g. TVOC)", shape = "invhouse", color="yellow" ];
    av1                                 [ label = "Transmitter Board\n(w. Zero & Span Adjust)" ];
    ac0                                 [ label = "Sensor\n(e.g. CO, NO2)", shape = "invhouse", color="yellow" ];
    ac1                                 [ label = "Transmitter Board\n(w. Zero & Span Adjust)" ];
    as0                                 [ label = "Sensor\n(e.g. CO2)", shape = "invhouse", color="yellow" ];
    FGMD                                [ label = "Formaldemeter", shape = "invhouse", color="yellow" ];
    SHT75                               [ label = "SHT7x Temp/Humi\nModule", shape = "invhouse", color="yellow" ];

    /* Top-Board and Main-Board Components */
    ADC                                 [ label = "10-bit\nAnalgue to Digital\nConverter" ];
    ZERO                                [ label = "Subtract D.C. Level\n(ZERO)" ];
    SPAN                                [ label = "Apply Gain = RANGE / SPAN\n(convert to \"ppm\" value)" ];
    sIEEE754                            [ label = "Convert to Floating-Point\n(using IEEE754 format)" ];
    vIEEE754                            [ label = "Convert to Floating-Point\n(using IEEE754 format)" ];
    LPF                                 [ label = "Apply Low-Pass Filter" ];
    Baseline                            [ label = "Subtract baseline\n(a floating-point value)" ];
    Offset                              [ label = "Subtract offset\n(an integer value -- ZERO)" ];
    PIC                                 [ label = "Processor" ];
    Relays                              [ label = "Relay outputs", shape = "house" fontcolor = "white", fillcolor="slateblue" ];

    /* NIC and Communication */
    CANBus                              [ label = "CAN Controller", style = dotted ];
    CANCntrl                            [ label = "CAN Controller", style = dotted ];
    ETRX2                               [ label = "ETRX2" ];
    ETRX2USB                            [ label = "ETRX2" ];
    ZigBeeNet   [ label = "ZigBee Wireless Network", style = filled, shape = "doublecircle", color = "deepskyblue1" ];

    /* Services */
    ZigBeeService                       [ label = "PPMonitor ZigBee Service" ];
    PPMService                          [ label = "PPMonitor Service" ];
    SQLDB                               [ label = "SQL Database", style = filled, shape = "folder", fillcolor = "bisque" ];

    /* Clients */
    Client                              [ label = "PPMonitor Client" ];
    Screen                              [ label = "PC Screen", shape = "house", fillcolor = "slateblue", fontcolor = "white"  ];
    Other                               [ label = "Other users\n& tools", style = filled, shape = "note", fillcolor = "bisque" ];

}